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STATE OF CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD
In the Matter of Amendment of the) DECISION 1631
City of Los Angeles' Water Right )
Licenses for Diversion of Water ) SOURCE: Lee Vining Creek
From Streams Tributary to Mono ) Walker Creek
Lake (Water Right Licenses 10191 ) Parker Creek
and 10192, Applications 8042 ) Rush Creek
and 8043) )
) COUNTY: Mono
CITY OF LOS ANGELES, )
)
Licensee )
)
DECISION AND ORDER AMENDING WATER RIGHT
LICENSES TO ESTABLISH FISHERY PROTECTION FLOWS
IN STREAMS TRIBUTARY TO MONO LAKE AND TO
PROTECT PUBLIC TRUST RESOURCES AT
MONO LAKE AND IN THE MONO LAKE BASIN
INTRODUCTION.....................................1
BACKGROUND.......................................3
PROCESS FOR REVIEW OF MONO BASIN WATER RIGHTS....12
PARTIES PARTICIPATING IN EVIDENTIARY HEARING.....19
RESTORATION AND PROTECTION OF FISHERY
RESOURCES IN THE MONO BASIN......................21
PROTECTION OF OTHER PUBLIC TRUST RESOURCES
AND BENEFICIAL USES OF WATER WITHIN THE
MONO BASIN.......................................77
BENEFICIAL USES SERVED BY WATER DIVERSIONS.......159
POTENTIAL ADVERSE ENVIRONMENTAL IMPACTS OF
REDUCED MONO BASIN WATER DIVERSIONS..............180
SUMMARY AND CONCLUSIONS..........................194
ORDER............................................196
CERTIFICATION....................................212
STATE OF CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD
In the Matter of Amendment of the) DECISION 1631
City of Los Angeles' Water Right )
Licenses for Diversion of Water ) SOURCE: Lee Vining Creek
From Streams Tributary to Mono ) Walker Creek
Lake (Water Right Licenses 10191) Parker Creek
and 10192, Applications 8042 ) Rush Creek
and 8043) )
) COUNTY: Mono
CITY OF LOS ANGELES, )
)
Licensee )
)
DECISION AND ORDER AMENDING WATER RIGHT
LICENSES TO ESTABLISH FISHERY PROTECTION FLOWS
IN STREAMS TRIBUTARY TO MONO LAKE AND TO
PROTECT PUBLIC TRUST RESOURCES AT MONO LAKE
AND IN THE MONO LAKE BASIN
BY THE BOARD:
1.0 INTRODUCTION
In 1940, the City of Los Angeles
and the City of Los Angeles Department of Water and Power
(hereinafter "Los Angeles" or LADWP")
received permits to divert water from four streams that
are tributary to Mono Lake in Mono County, California.
The permits authorized diversion of water for municipal
use and hydroelectric power production. At the time it
issued the permits, the Department of Public Works,
Division of Water Resources (a predecessor to the present
State Water Resources Control Board) concluded that the
California Water Code required issuance of the permits
despite anticipated damage to Mono Lake and other natural
resources.
Los Angeles developed the proposed
project and received Licenses 10191 and 10192 confirming
its water rights in 1974. Los Angeles' diversions of
water from the Mono Basin between 1941 and 1982 resulted
in approximately a 45-foot decline in the water level of
Mono Lake, approximately a 30 percent reduction in the
surface area of the lake, and substantial damage to the
environment. In 1979, the National Audubon Society, the
Mono Lake Committee, and others filed the first in a
series of lawsuits which challenged Los Angeles' water
diversions in the Mono Basin. The resulting court
decisions helped clarify the legal framework governing
the State Water Resources Control Board's (SWRCB) present
reexamination of the water rights previously granted to
Los Angeles.
In addressing the issues involved in
amending Los Angeles' water rights, this decision begins
with a summary of the factual background, relevant legal
requirements, the environmental review process, the
evidentiary hearing, and the positions of the various
parties. Next, the subjects of instream flows and other
conditions needed to restore and maintain fish resources
in the four affected streams are addressed. This decision
then addresses additional measures needed for protection
of other public trust resources in the Mono Basin. In
recognition of the outstanding ecological significance of
Mono Lake, this decision designates Mono Lake as an
Outstanding National Resource Water.
In determining the appropriate amendments
to Los Angeles' water right licenses for protection of
public trust resources, the decision considers the
effects which those amendments will have on the Los
Angeles water and power supply and on the environment.
The SWRCB's findings and conclusions are summarized in
Section 9.0 of the decision. The appropriate amendments
to Los Angeles' water right licenses are set forth in the
order at the end of the decision.
The order amends the licenses to set
quantified instream flow requirements for the protection
of fish in each of the four streams from which Los
Angeles diverts water. The order also establishes water
diversion criteria to protect wildlife and other
environmental resources in the Mono Basin. The water
diversion criteria: (1) prohibit the export of water from
the Mono Basin until the water level of Mono Lake reaches
6,377 feet above mean sea level; and (2) restrict Mono
Basin water exports in a manner that is intended to
result in the water level of Mono Lake rising to an
elevation of 6,391 feet in approximately 20 years.
The higher water level will protect
nesting habitat for California gulls and other birds
using the islands in Mono lake, maintain the long-term
productivity of the Mono Lake brine shrimp and brine fly
populations, enhance the scenic quality of the Mono
Basin, meet applicable water quality standards, and
reduce blowing dust from presently exposed lakebed areas
in order to protect health and comply with federal air
quality standards. The order also requires Los Angeles to
prepare restoration plans to restore the four streams
from which it diverts water and to restore a portion of
the waterfowl habitat which was lost due to the decline
of Mono Lake. Once the water level of 6,391 feet is
reached, it is expected that Los Angeles will be able to
export approximately 30.8 thousand acre-feet of water per
year from the Mono Basin.
2.0 BACKGROUND
This portion of the decision summarizes the
geographical, historical and legal background information
underlying the SWRCB's consideration of amendments to Los
Angeles' water right licenses.
2.1 The Mono Basin
The Mono Basin is a closed basin located east of the
crest of the Sierra Nevada Mountains (Figure 1). The
basin is widely recognized for its scenic qualities, with
the most prominent feature being Mono Lake. The Mono
Basin National Forest Scenic Area was established in 1984
in recognition of the panoramic views and scenery of the
Mono Basin. One of the distinctive scenic features of
Mono Lake is the presence of conspicuous mineral deposits
known as tufa towers, many of which are located Map --
page 4 within the Mono Lake Tufa State Reserve which was
established in 1982.
The high salinity and alkalinity of Mono
Lake have given rise to a unique ecological system of
lake dwelling invertebrates that provide food for large
numbers of migrating and nesting birds. Mono Lake is the
site of the State's largest breeding colony of California
gulls.
Mono Lake is a terminal lake in a
watershed with no outlet. The historic water level and
salinity of the lake have fluctuated considerably in
response to natural conditions. Since 1941, the water
elevation of Mono Lake has been affected by LADWP's
diversion of water from four tributary streams. The water
elevation of Mono Lake fell from 6,417 feet in 1941 to an
historic low of 6,372 feet in 1982. The water elevation
in the spring of 1994 was approximately 6,375 feet above
mean sea level. The surface area of the lake declined
from 54,924 acres in 1941 to approximately 37,688 acres
in 1982. (SWRCB 7, Appendix A, Table A-1.)
2.2 LADWP Water Diversion Project
LADWP diverts water from
Lee Vining Creek, Walker Creek, Parker Creek, and Rush
Creek to Grant Lake Reservoir located on Rush Creek. The
water then is exported from the Mono Basin through the
Mono Craters Tunnel approximately 11 miles to the upper
Owens River. The Mono Basin water commingles with water
in the upper Owens River and flows south to Lake Crowley,
a regulating reservoir on the upper Owens River. Water
released from Lake Crowley is diverted through three
hydroelectic power plants, Pleasant Valley Reservoir and
Tinemaha Reservoir before entering the Los Angeles
Aqueduct south of Bishop in Inyo County. The Los Angeles
Aqueduct leads to Fairmont Reservoir in Los Angeles
County from which it is distributed for a variety of
municipal uses in the City of Los Angeles.
Prior to 1970, diversions from the Mono
Basin were limited by the capacity of the Los Angeles
Aqueduct. By 1970, however, the aqueduct system had been
expanded and full diversion of flows from Lee Vining,
Walker, Parker, and Rush Creeks became common during
periods of average runoff. From 1974 to 1989, the City of
Los Angeles diverted an average of 83,000 acre-feet of
water per year from the Mono Basin. (SWRCB 7, p. 1-2.)
2.3 Issuance of Water Right Permits
and Licenses
The appropriative water rights under which LADWP diverts
water from the four Mono Basin streams were initiated by
the filing of Water Right Applications 8042 and 8043 in
1934. The applications were approved on April 11, 1940
and permits were subsequently issued by the Department of
Public Works, Division of Water Resources, a predecessor
agency to the present SWRCB. The Department of Public
Works recognized that the proposed water diversions would
adversely affect the Mono Basin, but concluded that it
was required to approve the project. This conclusion was
based on the provision of the Water Commission Act (now
codified as Water Code Section 1254) which states that
action upon applications to appropriate water shall be
guided by the policy that domestic use is the highest use
of water. (Department of Public Works, Division of Water
Resources Decision 455, April 11, 1940.)
Following completion of the second barrel
of the Los Angeles Aqueduct in 1970, LADWP was able to
divert the full flow of the four streams during periods
of average runoff. In 1974, the SWRCB issued Water Right
Licenses 10191 and 10192 which confirmed the city's
rights to divert water from the four streams. License
10191 authorizes storage and direct diversion of water
for municipal use. The total amount which may be
beneficially used in one year is 147,700 acre-feet.
License 10192 authorizes storage and direct diversion of
water for hydroelectric power generation. The combined
rate of direct diversion under both licenses is limited
to 200 cubic feet per second (cfs).
2.4 Court Decisions Affecting
Amendment of Water Right Licenses
The City of Los Angeles' diversion of water from the Mono
Basin has been the subject of extensive litigation over
the past fifteen years, resulting in three appellate
court decisions which provide guidance regarding
amendment of the water right licenses. In addition, the
city has been subject to several preliminary injunctions
governing water diversions on an interim basis. These
court decisions are discussed below.
2.4.1 National Audubon Society v.
Superior Court
In 1979, the National Audubon Society, the Mono Lake
Committee, Friends of the Earth, and four Mono Basin
landowners filed suit against the City of Los Angeles
seeking to force the city into allowing more water to
flow to Mono Lake. The plaintiffs argued that the city's
diversions of water from the Mono Lake tributaries
resulted in damage to Mono Lake in violation of the
public trust doctrine. Traditionally, the public trust
doctrine has been held to protect the public interest in
navigation, commerce, and fishing on navigable waters.
More recently, the doctrine has been interpreted to
protect a variety of natural resources and activities in
the vicinity of navigable waters and nonnavigable
tributaries of navigable waters.
The National Audubon Society suit
eventually reached the California Supreme Court which
entered its decision in 1983. (National Audubon
Society v. Superior Court 33 Cal.3d 419, [189
Cal.Rptr. 346] cert. denied, 464 U.S. 977.) In discussing
the applicability of the public trust doctrine to the
relief sought by plaintiffs, the court stated:
"The principal values plaintiffs
seek to protect...are recreational and ecological--the
scenic views of the lake and its shore, the purity of the
air and the use of the lake for nesting and feeding by
birds. Under Marks v. Whitney, supra, 6
Cal.3d 251, 98 Cal.Rptr. 790, 491 P.2d 374, it is clear
that protection of these values is among the purposes of
the public trust." (Id. at 435, 189 Cal.Rptr. at
356.)
The Audubon decision examined the
relationship between the public trust doctrine and the
California appropriative water rights system. The Court
recognized that in some cases the public interest served
by water diversions may outweigh harm to public trust
resources, but it held that harm to public trust
resources should be avoided or minimized if feasible.
(Id. at 427, 189 Cal.Rptr. at 349.) The Court went on to
state that under Article X, Section 2 of the
California Constitution: "All uses of water,
including public trust uses, must conform to the standard
of reasonable use." (Id. at 444, 189 Cal.Rptr. at
362.) The Court concluded that Los Angeles' water rights
were granted without consideration of the effects of the
diversions on the public trust resources of the Mono
Basin and that, therefore, a responsible body should
reconsider the allocation of water from the Mono Basin
streams. (Id. at 447 and 452, 189 Cal.Rptr. at 365 and
369.) The Court also ruled that the SWRCB and the courts
have concurrent jurisdiction to consider the effect of
water diversions on public trust resources.
2.4.2 California Trout v. State
Water Resources Control Board
In 1985, California Trout, Inc., the National Audubon
Society and the Mono Lake Committee filed suit seeking a
court order directing the SWRCB to rescind Los Angeles'
water right licenses. The plaintiffs argued that the
licenses should be rescinded because they did not include
a condition requiring bypass of water for protection of
fish in the four affected streams as required by Section
5946 of the Fish and Game Code. In 1989, the California
Court of Appeal directed that the SWRCB amend the city's
licenses to include the condition required by Fish and
Game Code Section 5946. (California Trout Inc. v. State
Water Resources Control Board ("Cal Trout I")
218 Cal.App. 187 [255 Cal.Rptr. 184, 213].)
In 1990, the Court of Appeal entered a
second decision which specified the following language to
be added as a condition to the city's licenses:
"In accordance with the
requirements of Fish and Game Code section 5946, this
license is conditioned upon full compliance with section
5937 of the Fish and Game Code. The licensee shall
release sufficient water into the streams from its dams
to reestablish and maintain the fisheries which existed
in them prior to its diversion." (California
Trout Inc. v. Superior Court ("Cal Trout
II") 218 Cal.App 187 [266 Cal.Rptr.788].)
The Court of Appeal left determination of
the precise long-term flow rates to the SWRCB and
assigned the task of setting interim flow requirements to
the Superior Court. (Id. at 212, 266 Cal.Rptr. at 803 and
804.) On April 4, 1990, the SWRCB amended the licenses to
include the general condition specified by the court. The
specific flow rates which are to be added as conditions
of the licenses are discussed in Sections 5.0 through
5.4.3 below.
2.4.3 Interim Relief and Stay Order of
El Dorado County Superior Court
Currently, all pending lawsuits concerning LADWP's water
diversions in the Mono Basin are coordinated under the
title of Mono Lake Water Rights Cases in the
Superior Court for El Dorado County. (El Dorado County,
Superior Court Coordinated Proceeding Nos. 2284 and
2288.) On December 6, 1989, the Superior Court entered a
preliminary injunction which ordered that LADWP must
allow sufficient water to pass its Mono Basin diversion
facilities to restore and maintain the water level of
Mono Lake at elevation 6,377 feet. On June 14, 1990, the
Superior Court entered a preliminary injunction that
established interim flows for the protection of fish in
all four Mono Basin streams from which Los Angeles
diverts water under its licenses. The interim flow
requirements presently in effect were set in an amended
order entered by the Superior Court on July 26, 1990.
On April 17, 1991, the Superior Court
renewed the preliminary injunction requiring LADWP to
bypass sufficient water to maintain the water level of
Mono Lake at or above 6,377 feet. In order to comply with
the preliminary injunctions, the city has not exported
any water from the Mono Basin since 1989 except for a
small amount needed to conduct a fishery study on the
upper Owens River.
On September 29, 1989, upon motion of the
SWRCB, the Superior Court entered an order staying
further judicial proceedings on the merits of the
coordinated litigation pending completion of the SWRCB's
review of the city's water right licenses or September 1,
1993, whichever came first. By order dated June 8, 1993,
the Court extended the stay of proceedings until the
earlier of September 1, 1994 or completion of this
Board's proceedings. The process which the SWRCB has used
in developing amendments to the city's water right
licenses is summarized in Sections 3.0 through 3.3.3
below. The Superior Court has continued to exercise
jurisdiction over interim relief questions pending SWRCB
amendment of the licenses.
2.5 Physical Solution Doctrine
In resolving disputes involving
competing uses of water, California courts have
frequently considered whether there is a "physical
solution" available by which competing needs can
best be served. (Peabody v. Vallejo, 2
Cal.2d 351, 383-384 [40 P.2d 486] (1935); City of Lodi
v. East Bay Municipal Util. Dist., 7 Cal.2d 316
[60 P.2d 439] (1936).) Adoption of a physical solution is
consistent with the constitutional goal of promoting
maximum beneficial use of the State's water resources.
The SWRCB has previously concluded that the physical
solution doctrine can be employed to establish a flow
regime for protection of fish in which the required
releases of water from storage exceed the rate of inflow
to a reservoir at a particular time. (SWRCB Order
WR 90-16, pp. 8-9.) In the present situation,
the California Court of Appeal decision recognized that,
as the price of continued appropriation of water, an
appropriator can be compelled to take reasonable steps to
restore the streams and fisheries. (California Trout
Inc. v. Superior Court, supra., 218 Cal.App.3d
at 210, n.6 [266 Cal.Rptr. at 801-802, n.6].)
Thus, in establishing the flow
requirements necessary to comply with Fish and Game Code
Section 5937 in the present situation, the SWRCB has
examined the relationship between flows and fishery
habitat, as well as the availability of other measures
which would help restore the fishery while allowing
diversion of some water for municipal use. (See Sections
5.0 through 5.3.) Similarly, in examining the use of
water at Mono Lake for providing waterfowl habitat, this
decision acknowledges that there are alternative ways of
restoring a portion of the lost waterfowl habitat without
requiring a return to the pre-1941 lake elevation. (See
Section 6.4.7.)
2.6 Summary of Legal Framework
Governing Amendment of Los Angeles' Water Right Licenses
All diversions and use of water in California are subject
to the mandate of Article X, Section 2 of the California
Constitution to maximize the beneficial use of water and
to prevent the wasteful or unreasonable use, method of
use, or method of diversion. The Audubon decision
establishes that the SWRCB has the additional
responsibility to consider the effect of water diversions
upon interests protected by the public trust and to avoid
or minimize harm to public trust uses to the extent
feasible. The public trust has been held to protect a
broad range of values including fishing, hunting,
swimming, boating, recreation, scenic values, air
quality, and wildlife habitat. (National Audubon
Society v. Superior Court, supra., 33 Cal.3d
at 434 and 435, 189 Cal.Rptr. at 356.) The California
Supreme Court concluded that the lack of consideration to
protection of public trust uses at the time that the City
of Los Angeles acquired its appropriative water rights in
the Mono Basin requires that this Board or the courts
take "a new and objective look at the water
resources of the Mono Basin." (Id., 33 Cal.3d at
452, 189 Cal.Rptr. at 369.) The SWRCB's review of Los
Angeles' water rights is subject to Fish and Game Code
Section 5946 which applies to permits and licenses for
water diversions in portions of Inyo and Mono Counties.
Section 5946 requires that the licenses be conditioned
upon full compliance with Fish and Game Code Section
5937. In this instance, the Court of Appeal has
interpreted the applicable law to require that LADWP must
release sufficient water into the streams "to
reestablish and maintain the fisheries which existed in
them prior to its diversion of water." ("Cal
Trout II," supra., 218 Cal.App.3d at 213, 266
Cal.Rptr. at 803 and 804.) With respect to flows needed
for protection of fish, the Court of Appeal ruled that
"the Legislature has already balanced the competing
claims for water from the streams affected by section
5946 and determined to give priority to the preservation
of their fisheries." (Id., 218 Cal.App.3d at 201,
266 Cal.Rptr. at 796.)
In accordance with the judicial decisions
discussed above, the SWRCB's approach is to determine
what flows are needed for protection of fish. Then the
decision addresses the need for additional water and
other measures to protect public trust resources at Mono
Lake and the surrounding area in view of the competing
uses of water by Los Angeles. Finally, the California
Environmental Quality Act ("CEQA," Public
Resources Code Section 21000, et seq.) requires
addressing how best to mitigate or avoid potential
adverse environmental impacts that may occur as a result
of the changes in Mono Basin water diversions required by
this decision.
3.0 PROCESS FOR REVIEW OF MONO BASIN
WATER RIGHTS
In reviewing Los Angeles' water rights and competing uses
to be made of Mono Basin water resources, the SWRCB has
utilized information developed through preparation of an
environmental impact report and other evidence presented
during the course of a lengthy water right hearing. In
evaluating anticipated effects of alternative proposals
for regulating the city's diversions, the SWRCB
considered evidence presented at the hearing as well as
projections developed using computer models introduced
into evidence during the hearing.
3.1 Environmental Impact Report
On September 11, 1989, the SWRCB held a public hearing to
provide an opportunity for interested parties to comment
on the suggested scope of the SWRCB's review of Mono
Basin water diversions, public trust uses of Mono Basin
water, and other beneficial uses of water diverted from
the Mono Basin. Interested parties were also invited to
comment on the scope of the environmental impact report
(EIR) being prepared as part of the SWRCB's review.
On October 10, 1989, SWRCB staff
established five technical advisory groups to assist in
identifying specific environmental issues to be addressed
in the Draft EIR and to help identify relevant
information that could be used in the environmental
review process. Participants in the technical advisory
groups included representatives of federal, state and
local governments (including the City of Los Angeles),
environmental groups, colleges and universities, private
consultants and members of the public. The groups met for
varying lengths of time, with the technical advisory
group on hydrology and aqueduct operations continuing to
meet into early 1994.
The Notice of Preparation for the EIR was
issued on January 4, 1990. The notice was mailed to over
500 groups and individuals and widely published in
newspapers. SWRCB staff prepared a scope of work and
requested proposals for preparation of an EIR from over
40 resource management consulting firms. The proposals
that were submitted were reviewed by SWRCB staff, Los
Angeles, and a joint review team composed of
representatives from Mono County, California Trout, Inc.,
the U.S. Forest Service, the Department of Fish and Game
(DFG), the National Audubon Society and the Mono Lake
Committee. Jones and Stokes Associates, Inc. was selected
as the primary EIR contractor in June 1990, and numerous
other scientists having expertise on the Mono Basin were
retained as subcontractors.
In preparing the draft EIR, the
consultant considered information from numerous sources
including: a 1987 National Academy of Sciences report
titled, "The Mono Basin Ecosystem: Effects of
Changing Lake Level;" a 1988 report prepared by the
University of California, Riverside, Water Resources
Center titled, "The Future of Mono Lake: Report of
the Community and Organization Research Institute (CORI)
Blue Ribbon Panel;" and the United States Forest
Service's 1990 "Final Environmental Impact Statement
and Comprehensive Management Plan, Mono Basin National
Forest Scenic Area."
A three-volume draft EIR was distributed
for public comment on May 26, 1993. Twenty-eight
auxiliary reports on various subjects were also prepared.
Numerous governmental agencies, environmental groups, and
individuals submitted comments on the Draft EIR. Many of
the consultants who assisted in preparing the Draft EIR
presented testimony at the water right hearing.
In accordance with provisions of the
California Environmental Quality Act, the Final EIR
identifies measures that are considered necessary to
avoid, reduce, or mitigate potential adverse
environmental impacts resulting from this decision. This
decision includes findings of overriding considerations
with respect to those adverse environmental effects which
cannot feasibly be reduced or mitigated below a level of
significance. (Title 14, Cal. Code of Regs., Section
15093.)
3.2 Water Right Hearing
Following a prehearing conference on April 19, 1993, the
SWRCB issued a hearing notice on June 30, 1993 regarding
amendment of Los Angeles' water right licenses for
diversion of water from streams tributary to Mono Lake.
The June 30, 1993 hearing notice explained that the SWRCB
intended to amend the licenses to establish quantified
instream flow requirements as necessary to comply with
the public trust doctrine, the California Fish and Game
Code, and judicial rulings requiring that the specified
flows be sufficient to reestablish and maintain fisheries
equivalent to those which existed prior to the diversion
of water by Los Angeles. The notice also explained that
the SWRCB intended to amend Los Angeles' Water Right
Licenses 10191 and 10192 to specify water surface
elevation requirements for Mono Lake and other conditions
necessary to provide appropriate protection for public
trust resources and the beneficial uses of water of Mono
Lake and its tributaries.
In addition to identifying the procedures
governing participation in the evidentiary portion of the
water right hearing, the hearing notice provided that
interested parties could present non-evidentiary policy
statements on the issues under consideration. Hearing
sessions for receipt of policy statements were held in
Los Angeles, Mammoth Lakes, and Sacramento.
The evidentiary hearing began on October
20, 1993 and ended on February 18, 1994. The evidentiary
hearing was held in Sacramento with the exception of one
day in Lee Vining to receive testimony from Mono Basin
residents. Board Member Marc Del Piero served as hearing
officer. There were over 40 hearing days, including three
days for non-evidentiary policy statements. Testimony was
provided by more than 125 witnesses, and over 1,000
exhibits were introduced into evidence. Parties
participating in the evidentiary hearing were allowed
until March 21, 1994 to submit legal briefs and until
April 29, 1994 to submit reply briefs.
3.3 Use of Computer Models to Assist
in Evaluating Anticipated Effects of Alternative
Proposals For Regulating Mono Basin Water Diversions
Much of the evidence presented during the hearing was
developed through use of computer modeling. Computer
models were utilized to help evaluate or predict: (1) the
amount of fishery habitat available at different flow
levels; (2) the impacts of various alternative water
diversion scenarios on the water elevation of Mono Lake
and the water supply available to Los Angeles; (3)
expected runoff under different hydrologic conditions;
and (4) the anticipated economic cost of alternative
approaches to regulating water diversions.
Computer models can be used to: (1)
estimate conditions that are not readily susceptible to
direct measurement and, (2) to estimate future conditions
or effects that would be expected to occur under various
assumed conditions. In situations where a computer model
provides the only feasible way of evaluating expected
conditions, the results produced by a computer model may
provide the best evidence available to the
decision-maker.
Sections 3.3.1 and 3.3.3 briefly describe
the computer models used in reaching this decision or
which will be used in implementing requirements of this
decision. In each case, the SWRCB recognizes that there
is a degree of uncertainty inherent in computer modeling.
Nevertheless, the record indicates that the computer
models discussed in Sections 3.3.1 through 3.3.3 below
provide the best available tools for evaluating the
particular conditions or effects analyzed by the
respective models. With regard to evaluation of economic
effects, the SWRCB did not rely on the computer modeling
results submitted by LADWP or California Trout, Inc. for
the reasons explained in Section 7.1.5.
3.3.1 IFIM/PHABSIM Fisheries Flow
Models
The DFG flow
recommendations for fish protection in Lee Vining Creek,
Rush Creek, and the upper Owens River were based upon
evaluation of the relationship between trout habitat and
flow as determined using the Instream Flow Incremental
Methodology (IFIM) and the Physical Habitat Simulation
Model (PHABSIM). (DFG 3, p. 2.) The EIR consultant
did a similar fishery study for the middle Owens River.
(SWRCB 13W, p. 2-1.)
The fishery study consultants collected
on-site data and measurements of various parameters such
as water depth, velocity, substrate, and cover
conditions. The data were used to develop hydraulic
models of the streams in question. The hydraulic models,
and information on fish habitat criteria, were utilized
to determine the amount of weighted useable area (WUA)
available to various life stages of target species at
different flows. Data showing the relationship between
flows and weighted useable area, together with
information on other factors affecting the fishery, were
then used to develop recommended streamflow regimes for
the species of interest. (DFG 117, p. 1-18.)
Although in some instances the flow
requirements established in this decision vary from the
recommendations set forth in the various fishery studies,
the SWRCB believes that the determinations of weighted
useable area for identified lifestages of specified
species provide a reasonable basis for estimating the
amount of habitat available at differing levels of flow.
Further discussion regarding fishery habitat on the
streams under consideration is provided in Sections 5.0
through 5.4.4 below.
3.3.2 Los Angeles Aqueduct Monthly
Planning (LAAMP) ModelThe
water supply and lake level impacts of various methods of
regulating LADWP's water diversions were estimated using
the Los Angeles Aqueduct Monthly Planning Model (LAAMP
Model) which was developed as part of the environmental
impact report process. The LAAMP Model was developed as a
tool to simulate the relationships between flows in the
tributary streams, Mono Lake surface elevation, and water
deliveries to Los Angeles through the Los Angeles
Aqueduct. In using the LAAMP Model to predict various
anticipated effects of different water diversion
scenarios, average monthly streamflow data are used for
the 50-year period of record covering runoff years 1940
through 1989. The LAAMP Model was developed to allow the
user to account for operational objectives, physical
constraints of diversion facilities and reservoirs, and
applicable agreements governing LADWP's water diversion
and storage facilities.
Expert testimony was presented by the EIR
consultants and others regarding predicted impacts on
water supply, lake level and flows of various
alternatives identified in the Draft EIR and variations
of those alternatives. In response to comments on the
LAAMP Model used in preparing the Draft EIR (LAAMP
Version 2.0), an Operations Modeling Technical Advisory
Group met during the course of the hearing to consider
revisions to the LAAMP model to improve its predictive
capability. Following revisions to the model, the EIR
consultants presented testimony and exhibits regarding
effects of various diversion scenarios on lake level and
on the water supply available to Los Angeles as
determined through use of the revised LAAMP model. (SWRCB
40 through SWRCB 48; RT XXXV, pp. 13-105.)
Two revised versions of the model,
designated as LAAMP Version 3.3 and LAAMP Version 3.31
were received into evidence. (SWRCB 49.) As discussed in
Section 7.1.2 below, the SWRCB used LAAMP Version 3.31 to
assist in evaluating the anticipated impacts of the
requirements established by this decision.
3.3.3 LADWP Runoff Forecast Model
Hydrologic classifications or year types are relative
indicators of the water available in a hydrologic basin
due to all types of precipitation and runoff. In order to
reflect the variation in flows which occurs under natural
conditions, DFG's fishery flow recommendations for Lee
Vining Creek and Rush Creek vary depending upon the
amount of runoff expected in a given year. DFG's
"dry year" classifications include the years
having runoff which would be exceeded in 80 percent of
all water years while "wet years" are
considered to be those years having runoff that would be
exceeded in only 20 percent of all water years.
"Normal years" are those years which fall in
between the 20 percent and 80 percent range. (DFG 170A,
p. 1.) In terms of average runoff equating to the various
year type classifications for the Mono Basin, a dry year
is a year having 68.5 percent or less of average runoff,
a wet year is a year having 136.5 percent or more of
average runoff and a normal year is any year having
between 68.5 percent and 136.5 percent of average runoff.
The average runoff value is based on a fifty-year moving
average of runoff which is recalculated every five years.
(LADWP 133, p. 1.)
LADWP prepares runoff forecasts for the
Mono Basin to assist in determining the amount of water
expected to be available from the Los Angeles Aqueduct.
(LADWP 55, p. 8.) The LADWP forecasts correspond to the
runoff year which goes from April 1 through March 31. The
forecasts are made near the first of the month in
February, March, April, and May. LADWP uses precipitation
data, snow survey data and weather forecasts as input
data for LADWP's Runoff Forecast Model. (LADWP 147, p.
1.) Most precipitation in the Mono Basin generally has
occurred by May 1, so the May 1 forecast is reasonably
accurate. (LADWP 52, p. 7.) For purposes of determining
the applicable flow requirements for fishery protection,
as well as for channel maintenance and flushing purposes,
the conditions which are added to LADWP's water right
licenses by this decision refer to runoff year type
classifications of wet, normal and dry years based on
projections from the LADWP Runoff Forecasting Model for
the Mono Basin.
4.0 PARTIES PARTICIPATING IN
EVIDENTIARY HEARING
The parties
who participated in the evidentiary hearing were the
California Air Resources Board (ARB), the California
Department of Fish and Game (DFG), the California State
Lands Commission (SLC), the California Department of
Parks and Recreation (DPR), California Trout, Inc. (CT),
the City of Los Angeles and the City of Los Angeles
Department of Water and Power (Los Angeles or LADWP), the
Great Basin Unified Air Pollution Control District
(GBUAPCD), Haselton Associates (HASELTON), the National
Audubon Society and the Mono Lake Committee
(NAS&MLC), the Sierra Club (SC), the Metropolitan
Water District of Southern California (MWD), the United
States Fish and Wildlife Service (USFWS), the United
States Forest Service (USFS), and the United States
Environmental Protection Agency (USEPA).
In addition to evidence presented by the
parties, SWRCB staff introduced documents from the files
relevant to the SWRCB's review process and called upon
the EIR consultant to present testimony and exhibits
relative to preparation of the Draft EIR and subjects
analyzed in that document.
The large number of parties and issues
involved makes it impractical to summarize each party's
position with respect to each specific issue considered.
In general, many of the parties urge the SWRCB to adopt
the DFG streamflow recommendations and to establish a
minimum lake level at or above 6,390 feet in order to
protect various public trust resources of the Mono Basin.
The National Audubon Society and Mono Lake Committee
recommend adoption of the DFG streamflow recommendations
and a managed lake level of 6,405 feet. LADWP introduced
a revised version of its Mono Lake Management Plan which
calls for a lake level of 6,377 feet, and which provides
for specified minimum streamflows in the four affected
streams. Frank Haselton, appearing on behalf of John
Arcularius and the Arcularius Ranch, urges that
consideration be given to protection of the fishery in
the upper Owens River. The Metropolitan Water District of
Southern California presented evidence regarding future
water supplies available to its service area, but made no
recommendations regarding amendment of Los Angeles' water
rights.
Following the close of the evidentiary
hearing, several of the parties submitted legal briefs
summarizing their positions, arguments and
recommendations on various issues.
5.0 RESTORATION AND PROTECTION OF
FISHERY RESOURCES IN THE MONO
BASIN
As discussed in Section 2.6 above, the SWRCB's first task
in this instance is to determine the flows needed to
reestablish and maintain the fisheries that existed prior
to LADWP's diversion of water from the four Mono Basin
streams. DFG conducted detailed fishery studies and
presented recommendations regarding minimum flows for
protection of fish in each of the four Mono Basin streams
from which Los Angeles diverts water. Alternative
streamflow recommendations for Rush and Lee Vining Creeks
were presented by LADWP. In addition to presenting
evidence regarding minimum flow recommendations for
providing fishery habitat, the parties also introduced
considerable evidence regarding the desirability of
periodic channel maintenance or flushing flows.
Following evaluation of evidence
regarding desired streamflows, this decision considers
other related measures to help reestablish and maintain
pre-project fishery resources. Flows and other fishery
restoration measures are discussed on a stream-by-stream
basis beginning with the northernmost stream from which
LADWP diverts water and proceeding southward.
5.1 Lee Vining Creek
5.1.1 Pre-Project Conditions
The fishery that existed in Lee Vining Creek prior to
diversion of water by Los Angeles was described by former
DFG employee Elden Vestal as a good trout fishery which
sustained catchable brown trout averaging 8 to 10 inches
in length. (CT 5.) There were several other accounts that
depicted the fishery as a good trout stream with an
abundance of 8 to 10 inch trout, with some trout reaching
13 to 15 inches. (NAS&MLC 124, p. 14.) The Draft EIR
summarized testimony from 1990 proceedings in El Dorado
Superior Court which indicated that plantings of hatchery
reared trout fingerlings and catchable rainbow trout were
common in the early 1900s. In 1940, the predominate fish
in Lee Vining Creek were brown trout. Small pockets of
rainbow trout were present along with the rare occurrence
of eastern brook trout. (SWRCB 7 Vol. 1, p. 3 D-7.)
No definitive evidence of pre-diversion
fish populations in Lee Vining Creek was presented. Based
on the evidence presented, we conclude that the
pre-project fishery in Lee Vining Creek primarily
consisted of brown trout augmented by planting of brown
trout fingerlings and catchable rainbow trout. The
planted fish probably contributed to the high angling
success. The instream flow requirements established in
this decision are designed to provide the conditions
necessary to maintain a resident brown trout fishery
similar to that which existed in Lee Vining Creek prior
to the diversion of water by LADWP.
The physical conditions on Lee Vining
Creek prior to 1941 were the subject of extensive
testimony and numerous exhibits. (E.g., SWRCB 7, LADWP 7
and 9, NAS&MLC 116, 120, 124, 125, 127, 129, 136 and
175.) A large number of the same documents were submitted
by several of the interested parties. In addition to the
testimony of Elden Vestal and several long-time residents
of the Mono Lake area, the SWRCB heard testimony from
several expert witnesses who had reviewed aerial
photographs, hydrologic records and other documentary
evidence relevant to the physical conditions on Lee
Vining Creek prior to the LADWP diversions. Despite the
amount of testimony and exhibits, detailed information
regarding the pre-1941 physical conditions in Lee Vining
Creek is limited.
The Trihey and Associates report titled
"Comparison of Historic and Existing Conditions on
Lower Lee Vining Creek, Mono County, California" by
Mitchell Katzel (NAS&MLC 116), summarized much of the
historical information presented in the exhibits
mentioned above. The Trihey and Associates report also
was based upon technical studies and investigations
conducted by a multidisciplinary planning team which
included individuals who testified on behalf of various
parties, including LADWP, NAS&MLC, and DFG. The
report concluded that there has been little geomorphic or
vegetative change between the LADWP diversion dam and
Highway 395. (NAS&MLC 116, p. 1.) Most of the impacts
of the exportation of water by LADWP occurred below
Highway 395. Fire in the early 1950s destroyed much of
the riparian vegetation. Livestock grazing also impacted
the riparian vegetation and caused the local breakdown of
stream banks. Once the riparian vegetation was in
decline, the combined effects of fire, grazing and the
limited water supply contributed to a near total loss of
vegetation in the area described as segment 3 in the
report. Additional information regarding riparian
vegetation is provided in Section 6.3 below.
Prior to the diversion of water by LADWP,
lower Lee Vining Creek was a multiple channel system
characterized by a single main channel and between two
and five subsidiary channels. The total main channel
length between Highway 395 and the county road was
approximately 9,800 feet and the total subsidiary channel
length was approximately 15,600 feet. Both the main and
subsidiary channels were generally narrow, consisting of
deep water habitat which was provided by moderate flows.
The main channel width was approximately 13 feet and
subsidiary channels ranged from 5 to 8 feet wide. High
streamflows readily increased water depth in the main and
subsidiary channels. High streamflows also over topped
the bank and deposited organic rich sediment on the
floodplain. (NAS&MLC 175.)
5.1.2 Flows for Providing Fishery
Habitat
The major instream
flow study on Lee Vining Creek was conducted during 1990
and 1991 by the firm of Aquatic Systems Research under
the direction of DFG. This comprehensive investigation
used the instream flow incremental methodology (IFIM) in
order to determine instream flow requirements for brown
trout in lower Lee Vining Creek. Study elements included:
delineating and quantifying existing aquatic habitat;
assessment of historic and existing hydrology;
development of weighted useable area/stream discharge
relationships for brown trout fry, juvenile, adult and
spawning life stages; estimation of existing fish
populations by habitat type; examination of fluvial
geomorphology; monitoring and simulating water
temperature; and assessment of riparian vegetation,
factors that lead to ice formation and fish food
availability. The DFG study evaluated flows for the main
channel of Lee Vining Creek, but made no flow
recommendations for additional channels.
DFG presented recommendations for
instantaneous flow releases to lower Lee Vining Creek on
a monthly basis based on information contained in
"The Lee Vining Creek Stream Evaluation Report 93-2,
Volumes 1 and 2," dated July 1993. (DFG 54 and 55.)
The flows in the 1993 report were presented as DFG's
recommendations for maintaining fish in good condition
pursuant to Fish and Game Code Sections 5937 and 5946.
(DFG 3, p. 4.) At the time the Draft EIR was circulated
for review and comment, the instream flow information
which DFG had provided to the EIR consultant was based on
a report from DFG labeled "Draft Final, July 13,
1992." The information in DFG's final report is
considerably different than the information in the 1992
report which was used in preparing the Draft EIR.
The LADWP Mono Lake Management Plan
describes proposed operational criteria which LADWP
contends will maintain Mono Basin resources, while
creating sufficient flexibility to operate the water
diversion system efficiently and allow for emergency
response. (LADWP 53, pp. 36-50.) The LADWP Mono Lake
Management Plan proposes minimum monthly instream flows
along with occasional channel maintenance flows. These
instream flow recommendations were intended to mimic the
natural hydrology. (LADWP 53, Section 2, p. 40;
LADWP 154, pp. 1-13.) A revised LADWP Mono Lake
Management Plan, as described in the written testimony of
Mr. William Hasencamp, proposes a new set of recommended
instream flows for Lee Vining, Parker, Walker and Rush
Creeks. (LADWP 133.) The revised instream flows are
proposed as part of a management scheme which LADWP
contends would maintain the fisheries while evening out
releases of water needed to maintain the water elevation
of Mono Lake. (LADWP 154, p. 2, Table 1.)
The NAS&MLC presented testimony by
Mr. Woody Trihey and Ms. Jean Baldridge which provided an
instream flow evaluation of possible effects upon stream
conditions of various flows regimes. This recommendation
was based upon the review of DFG's instream flow studies
and comparison of the restoration treatments implemented
for the Restoration Technical Committee. (NAS&MLC 1X,
pp. 2-7.) In a letter to SWRCB staff dated August 30,
1993, Mr. Trihey discussed his observations on Lee Vining
Creek during various flow events and the subsequent
effects upon the restoration treatments which were
implemented as part of the interim stream restoration
program under the direction of the El Dorado County
Superior Court. (NAS&MLC 104.)
Pending establishment of long-term flow
requirements by the SWRCB, the El Dorado County Superior
Court heard evidence and issued an order dated June 14,
1990 which set interim instream flows for Lee Vining
Creek and the other three streams from which LADWP
diverts water. Table 1 below shows the minimum instream
flow recommendations of DFG, the flows from the original
and revised versions of the LADWP Mono Lake Management
Plan, and the interim flows established by the Superior
Court. Table 1 also shows the flows which the SWRCB finds
to be appropriate to reestablish and maintain the
fisheries which existed in Lee Vining Creek before LADWP
began its diversion. The basis for determination of the
Lee Vining Creek instream flow requirements is discussed
following the table.
TABLE 1: LEE
VINING CREEK INSTREAM FLOW RECOMMENDATIONS/REQUIREMENTS*
*All flows are in cubic feet per second (cfs)
DFG Exhibits 54 and 55 identify
streamflow regimes for dry, normal and wet hydrologic
conditions which DFG believes would meet the needs of
trout in Lee Vining Creek. DFG biologist Gary Smith
testified that the recommended flows are minimum
instantaneous flow recommendations. DFG recommends
maintaining either the specified flows or the natural
flow, whichever is less. (RT XXXIX, 9:13-9:16.) In this
case, the inflow to the LADWP conduit diversion facility
is considered to be the natural flow. The DFG instream
flow recommendations are measured as releases from the
LADWP conduit diversion facility to Lee Vining Creek.
The criteria used by DFG to develop
streamflow recommendations for brown trout in lower Lee
Vining Creek for dry hydrologic years are described as
follows:
(a) Provide 90 percent of maximum
spawning habitat from October 1 through December 31;
(b) Maintain spawning streamflows from
January 1 through March 31; and,
(c) Provide 80 percent of maximum adult
habitat from April 1 through September 30. (DFG 54, p.
161, Table 34.)
DFG considered that the availability of
adult and spawning habitat was a limiting factor.
Consequently, providing habitat for adults and spawning
life stages was emphasized in order to develop a viable
and dynamic self-sustaining resident brown trout fishery.
The period of the year that adult habitat is a limiting
factor is from April 1 through September 30. Spawning of
brown trout generally occurs during the months of October
through December. Maintenance of the spawning flow regime
from December through April would provide a minimum flow
for adults during winter conditions and also provide
protection of the redds until all fry have emerged.
Weighted useable area/streamflow
relationships for fry, juvenile, adult and spawning brown
trout were developed using the physical habitat
simulation model (PHABSIM) within the IFIM model
technique. The results reported as weighted useable area
(WUA), in totals for the entire lower Lee Vining Creek,
are found in DFG Exhibit 55. (DFG 55, pp. 142-147, Tables
B-5 to B-8.) The results of the WUA analysis for adult
and spawning life stages are presented in Tables 2 and 3
below:
TABLE 2:
ADULT BROWN TROUT WEIGHTED USEABLE AREA (WUA) LEE VINING
CREEK
TABLE 3:SPAWNING HABITAT WEIGHTED USEABLE AREA (WUA)
LEE VINING CREEK
Examination of the weighted useable
area/streamflow relationships presented in Table 2
indicates that habitat for adults increases slowly as
flows increase above 37 cfs. Spawning flows of 25 cfs for
October 1 through March 31 provide 90 percent of the
maximum WUA for spawning while at the same time providing
70 percent of the maximum WUA for adults from January
through March 31. The limited availability of spawning
habitat substantiates the need to provide this particular
kind of habitat in all hydrologic year types in order to
ensure the continuation of the fishery. The DFG criteria
indicate that DFG's target is to maintain 90 percent of
spawning habitat and 80 percent of adult habitat. (DFG
54, p. 161.) Exhibit DFG 54 explains that providing
80 percent to 100 percent of habitat is the target for
all life stages of brown trout in Lee Vining Creek. (DFG
54, p. 160.)
In discussing findings from other
researchers, Dr. Tom Hardy, a fishery biologist
testifying on behalf of LADWP, testified that "...no
objective criteria has been validated to guide
investigators on what percentage reduction of optimal
habitat represents a significant impact or at what
exceedence value associated with either optimal or median
habitat represents adequate protection for the aquatic
resources." (LADWP 132, pp. 2-3.) Dr. Hardy
testified that several instream flow studies that he had
participated in targeted a range of 80 percent to 85
percent of the maximum WUA as optimal habitat conditions.
(LADWP 17, p. 58.) The LADWP Mono Lake Management Plan
recommends flows of 15 cfs from October 1 to March
31 which corresponds to 68 percent of the maximum WUA for
spawning and 56 percent of the maximum WUA for adults.
(LADWP 53, p. 40 Table A.) The 25 cfs figure for April 1
through September 30 corresponds to 70 percent of the
maximum WUA for adults. Thus, the LADWP plan suggests
flows which produce less WUA than recommended by DFG and
less than applied in several other studies in which Dr.
Hardy participated.
LADWP did not revise its recommendation
of the flows needed for maintenance of the fishery, but
its revised Mono Lake Management Plan recommended a
revised flow regime based on the need for increased flows
to maintain the water level in Mono Lake. The flows in
the revised management plan range from 20 to 35 cfs from
April through September, which correspond to a range of
approximately 64 percent to 80 percent of the maximum WUA
for adult brown trout. With the exception of the months
of June and July, the instream flow recommendations of
the revised LADWP Mono Lake Management Plan are below the
percentages recommended by DFG.
The criteria DFG used to develop
streamflow recommendations for brown trout in lower Lee
Vining Creek for normal hydrologic years include:
(a) Provide 100 percent of maximum
spawning habitat from October 1 through December 31;
(b) Maintain spawning streamflows from
January 1 through March 31; and
(c) Provide 90 percent of maximum adult
habitat from April 1 through September 30. (DFG 54, p.
162, Table 35.)
A flow of 40 cfs from October 1 through
March 31 would provide 100 percent of the maximum WUA for
spawning and 80 percent of the maximum WUA's for adults.
A flow of 54 cfs would provide 90 percent of the maximum
WUA for adults. (Tables 2 and 3 above.)
The criteria DFG employed to develop
streamflow recommendations for brown trout in lower Lee
Vining Creek for wet hydrologic years include:
(a) Provide 100 percent of maximum
spawning habitat from October 1 through December 31;
(b) Maintain spawning streamflows from
January 1 through March 31;
(c) Provide 90 percent of adult habitat
during April and September, to consider the needs of late
emerging fry, the seasonal transition in streamflow and
to simulate natural conditions; and,
(d) Provide 100 percent of maximum adult
habitat from May 1 through August 31. (DFG 54, p. 161,
Table 34.)
Testifying on behalf of NAS&MLC, Mr.
Trihey stated that "winter streamflows between 20
and 40 cfs, and summer streamflows between 40 and 100
cfs, would be very compatible with the restoration work
completed thus far on Lee Vining Creek."
(NAS&MLC 104, p. 2.) Routine flows above 60 cfs
begin to exceed velocities preferred by trout in Lee
Vining Creek downstream of LADWP's diversion. However, at
flows above 60 cfs, it would be beneficial to rewater two
of the ancillary channels in order to provide refuge
habitat from high stream velocities. These two ancillary
channels are the ancillary channel which parallels
Highway 120 in DFG study reach segment 2 and the
ancillary channel in DFG study segment 3 referred to by
the Restoration Planning Team as channel 3A-4. (DFG 54,
NAS&MLC 125.) If flows above 160 cfs are to occur
frequently during the next 10 to 15 years, then spawning
gravels in segment 1 should be periodically checked and
replaced as needed. Such gravels were naturally deposited
in segment 1 prior to 1941, but the LADWP diversion dam
stopped this natural process. (NAS&MLC IX, p. 6.)
The two instream flow recommendations
provided to the SWRCB are those in DFG's Lee Vining Creek
Stream Evaluation Report 93-2 (DFG 54 & 55) and the
flows described in the revised LADWP Mono Lake Management
Plan. The DFG report recommended instream flows to
maintain fish in good condition pursuant to Fish and Game
Code Sections 5937 and 5946. (DFG 3, p. 4.) The DFG's
instream flow recommendations were also presented as
flows needed to re-establish and maintain the conditions
that benefitted the fishery prior to Los Angeles'
diversions. (RT XX, 71:12-71:15.) DFG's study was based
upon data collected utilizing the previously described
IFIM and PHABSIM.
The LADWP recommendation was based upon
evaluation of flows needed to maintain the fishery, historic
hydrology, past operational practices and the need for
additional flows to meet Mono Lake level objectives. In
contrast to the DFG flow recommendations, LADWP
recommended the same flows for all hydrologic year types.
Although the flows recommended by LADWP would sustain a
fishery at some level in Lee Vining Creek, the SWRCB
concludes that those flows would not be sufficient to
reestablish and maintain the fishery that existed prior
to LADWP's diversion of water.
During wet hydrologic years, DFG
recommended an increase in the May, June, July and August
flows from 54 cfs to 95 cfs. (See Table 1 above.) The
rationale, described in DFG Exhibit 54, used for the
selection of this increase is to provide 90 percent to
100 percent of the maximum WUA for adult brown trout, 74
percent to 82 percent of the maximum fry habitat, 97
percent to 98 percent of the maximum juvenile habitat and
to provide 100 percent of the maximum WUA for spawning.
LADWP argued that providing 80 percent to
85 percent of the maximum WUA would maintain a viable
fishery and that it is not appropriate to select 100
percent of the maximum WUA. Instead, LADWP contends it is
more appropriate to select the point of change where a
significant increase in instream flow results in small
increases in habitat. (LADWP 17, p. 58.)
The instream flow requirements
established in this decision for May through August of
wet hydrologic years are different than the DFG and LADWP
recommendations. Examination of the flows associated with
90 percent and 100 percent of the maximum WUA for adult
brown trout suggests that a significant flow increase is
required to gain 10 percent in WUA. Ninety percent of WUA
is provided at a flow of 54 cfs, whereas 100 percent of
WUA would require 95 cfs. A reduction of flow from 95 to
54 cfs actually results in a slight increase in useable
habitat for juvenile trout which are also present during
the April through September period.
In his written testimony, Mr. Trihey
concludes that "...the restoration treatments
implemented thus far will provide good to very good fish
habitat (e.g., depth and velocity for adult and juvenile
fish) over a broad range of streamflows."
(NAS&MLC 1X, p. 2.) A minimum instream flow
requirement of 54 cfs for April through September would
provide 90 percent of the maximum WUA for adults and 98
percent of the maximum WUA for juveniles. In combination
with the restoration work already completed and the other
fishery protection measures established in this decision,
a flow of 54 cfs for April through September in both
normal and wet years will be sufficient to restore and
maintain the fishery that existed in Lee Vining Creek
before LADWP began its Mono Basin diversions.
With the exception of the flow
requirements for May through August of wet years, we
adopt the fishery flow recommendations proposed by DFG
for Lee Vining Creek. Based on the evidence presented we
conclude that the following flows below the Lee Vining
conduit diversion facility will maintain fish in good
condition pursuant to Fish and Game Code Section 5937 and
that the specified flows are needed to reestablish and
maintain a fishery similar to that which existed in Lee
Vining Creek prior to the export of water by LADWP.
TABLE 4: INSTREAM FLOW
REQUIREMENTS FOR
LEE VINING CREEK*
DRY HYDROLOGIC CONDITIONS-LEE VINING CREEK
|
APRIL 1 THROUGH SEPTEMBER 30
|
|
OCTOBER 1 THROUGH MARCH 31
|
|
NORMAL HYDROLOGIC CONDITIONS-LEE VINING CREEK
|
APRIL 1 THROUGH SEPTEMBER 30
|
|
OCTOBER 1 THROUGH MARCH 31
|
|
WET HYDROLOGIC CONDITIONS-LEE VINING CREEK
|
APRIL 1 THROUGH SEPTEMBER 30
|
|
OCTOBER 1 THROUGH MARCH 31
|
|
* The instream flow requirements are the
flows specified in the table or
the inflow to LADWP's point of diversion, whichever is
less.
5.1.3 Channel Maintenance and Flushing
Flows
The DFG channel maintenance and flushing flow
recommendations for Lee Vining Creek were presented by
Dr. G. Mathias Kondolf in DFG Exhibit 170, later
superseded by DFG Exhibit 170A. Dr. Kondolf's written
testimony described the scope of his research in the Mono
Basin. (DFG 11.) The result of his reseach on Lee Vining
Creek is included in the Stream Evaluation Report on Lee
Vining Creek prepared by Aquatic System Research. (DFG 54
and 55.) DFG's Exhibit 170 proposed a specific channel
maintenance and flushing flow requirement for dry, normal
and wet hydrologic conditions. The revised exhibit (DFG
170A) reflects a revised ramping flow recommendation of
20 percent maximum change in streamflow per 24- hour
period during the ascending flow change and a 15 percent
maximum change per 24 hour period during the descending
flow. (RT XXXIX, 87:21-88:7.) The ramping rate
recommendation for Lee Vining Creek takes into account
the availability of upstream flows and LADWP's inablity
to regulate flows in Lee Vining Creek through release of
water from storage. Table 5 presents DFG's channel
maintenance and flushing flow recommendations for Lee
Vining Creek for the different hydrological year types.
TABLE 5:
CHANNEL MAINTENANCE & FLUSHING FLOW REQUIREMENTS LEE
VINING CREEK
|
|
|
|
|
160 CFS FOR A MINIMUM OF
THREE DAYS DURING
MAY, JUNE OR JULY
|
|
160 CFS FOR 30 CONSECUTIVE
DAYS DURING
MAY, JUNE OR JULY
|
RAMPING RATE - 20% CHANGE DURING ASCENDING
FLOW AND 15% DURING DESCENDING FLOWS PER 24 HOURS
|
The ramping requirement applies to
changes in flow made by LADWP.
LADWP is not required to compensate for natural
fluctuations in flow.
Testifying on behalf of LADWP, Dr. Robert
Beschta acknowledged that ramping rates should be
developed to prevent exceptionally rapid changes in flows
and that the occurrence of peak flows of varying timing
and magnitude should also be captured in the flow regimes
for Lee Vining Creek. (LADWP 9, Section 2, p. 23.) The
LADWP proposal for channel maintenance and flushing flows
for Lee Vining Creek is set forth in LADWP Exhibit 133,
Table 2.
Witnesses testifying on behalf of DFG and
LADWP both acknowledged the need for and provided
recommendations regarding channel maintenance and
flushing flows. LADWP provided little testimony in
support of the numbers recommended in its Management Plan
for channel maintenance and flushing purposes. The
explanation provided in support of the DFG recommendation
was more detailed and specific regarding the procedures
used to develop the recommendation. Consequently, for
purposes of this decision, the SWRCB adopts the channel
maintenance and flushing flow requirements for Lee Vining
Creek below the LADWP diversion facility as proposed by
DFG and as set forth in Table 5 above. The justification
for this requirement is based upon the documentation
provided by DFG, NAS&MLC and LADWP. (DFG 168 and
170A; NAS&MLC 1X; and LADWP 9.)
5.1.4 Additional Measures to Assist
Restoration of Pre-Project Fishery
The long period of little or no flow in the four Mono
Basin streams from which LADWP diverts water resulted in
significant losses of riparian vegetation and other
deterioration of channel conditions. In addition to
testimony regarding recommended flow regimes needed for
fishery habitat and channel maintenance, there was
considerable evidence presented regarding the potential
need for other measures which would assist in restoring
the four streams. During the period of the preliminary
injunction, considerable restoration work on Lee Vining
Creek has already been completed under the supervision of
the Restoration Technical Committee at the direction of
the El Dorado County Superior Court.
Mr. Trihey, testifying on behalf of
NAS&MLC and Cal Trout, described the extensive
restoration treatment performed by Trihey and Associates
under the direction of the Restoration Technical
Committee. These treatments are described in a number of
NAS&MLC exhibits. (NAS&MLC 106, 107, 108, 110,
111, 112, 115, 116, 119, 120, 123, 125, 126, 127, 128,
129, 130, 131, 132, 136, 175, 217.) Cal Trout also
submitted many of these same exhibits. During his
testimony, Mr. Trihey summarized the treatments that had
been completed at the time of the hearing. He suggested
that the restoration work completed thus far on Lee
Vining Creek has significantly improved the amount and
quality of the fish habitat in the portion of the stream
affected by LADWP diversions. (NAS&MLC 1Y, p. 17.)
As mentioned previously, Mr. Trihey's
written testimony states that the restoration treatments
implemented by the time of the hearing "will provide
good to very good fish habitat (e.g., depth and velocity
for adult and juvenile fish) over a broad range of stream
flows." (NAS&MLC 1x, p. 2.) Mr. Trihey
indicated that, with completion of a few minor tasks, the
stream will do well in time. (RT XXVIII, 21:20-22:12.)
The additional treatments recommended by
Mr. Trihey to complete the restoration of the conditions
that benefitted the prediversion fishery on Lee Vining
Creek include the following:
Segment 1--minor improvements to boulder
weirs which were installed to hold spawning gravel in
place during periods of channel maintenance flows,
removal of willows from a developing side channel at
restoration site LV 1.6, and replacement of approximately
300 cubic yards of spawning gravel at restoration sites
LV 1.1, 1.4, 1.6 and LV 1.7;
Segment 2--no further work is required;
Segment 3--add approximately 100 cubic
yards of spawning gravel to rewatered channels, place and
anchor large woody debris along the main channel, remove
excess sediment deposits from the B-1 channel, develop
pool habitat in segment 3-d and implement phase II of the
revegetation plan. (NAS&MLC 1Y, pp. 17-18.)
LADWP presented testimony by Dr. Beschta
that the most important restoration activity for Lee
Vining Creek is the return of continuous flows to the
creek. The elimination of grazing in the riparian
corridor and the reestablishment of streamflows has
created conditions which are allowing the successful
establishment and growth of riparian vegetation. Dr.
Beschta believes that structural approaches to
restoration provide little functional improvement to
stream or riparian systems and may actually be
counterproductive to providing sustainable fisheries
habitat. The only structural modification he recommended
was the construction of a sediment bypass system at the
Lee Vining Creek diversion. He recommended that the flows
released should: mimic the undisturbed flow regime;
include ramping constraints; and that the minimum flow
designed for the fishery should always be allowed to
bypass the diversion. (LADWP 9, Section 2, pp. 22-23,
39.)
Restoration which occurs through natural
processes is likely to be less dependent upon continued
human intervention. In some situations, however, active
intervention is necessary in order to restore conditions
that benefitted the fishery in Lee Vining Creek. The
record supports the conclusion that, in addition to the
flow requirements discussed above, the following measures
should be undertaken to restore and maintain in good
condition the fishery that existed in Lee Vining Creek
prior to the diversion of water by LADWP:
1. A sediment bypass system should be
constructed at the Lee Vining Creek diversion.
2. Livestock grazing should be prohibited
within the lower Lee Vining Creek riparian corridor for a
minimum of ten years from the date of this order. Any
resumption of grazing in the future should be subject to
approval by the Chief of the Division of Water Rights of
a plan prepared by LADWP in consultation with DFG.
3. Boulder weirs as described by Mr.
Trihey in NAS&MLC Exhibit 1Y should be anchored
sufficiently to hold the spawning gravel in place during
the anticipated channel maintenance and flushing flows.
4. Two auxiliary flood flow channels
should be reopened. The auxiliary stream channel that
parallels Highway 120 should be reconnected to the main
channel. The channel described by the Restoration
Planning Team as 3A-4 should also be reconnected to the
main channel. The alteration of the stream and the
auxiliary channels should be kept at a minimum in order
to minimize disturbance of the riparian area.
5. LADWP should evaluate the need for
spawning gravel distribution in Lee Vining Creek below
the LADWP diversion facility.
6. Vegetation disturbed by construction
for any of the restoration activities required by this
order should be restored. Revegetation should commence as
soon as construction activities have been completed.
7. LADWP should install a continuous
recording device satisfactory to the Chief of the
Division of Water Rights to measure the flow at the Lee
Vining Creek diversion and the flow in the stream
immediately below the Lee Vining Creek diversion.
8. LADWP should consult with DFG
regarding the revegetation necessary to maintain fish in
good condition in Lee Vining Creek.
The installation of a continuous flow
recording device and the prohibition of grazing in the
riparian corridor can be implemented without the need for
a lengthy planning period. The other measures specified
above should be addressed in the stream restoration plan
required to be prepared under the provisions of this
decision.
5.2 Walker Creek
5.2.1 Pre-Project Conditions
In comparison to amount of
evidence presented regarding Lee Vining and Rush Creeks,
very little information was presented concerning pre-1941
conditions on Walker Creek. DFG's recommendations for
instream flows and restoration requirements on Walker
Creek are presented in the Walker Creek Stream Evaluation
Report 92-1, Volumes 1 and 2. (DFG 56 and 57.)
The descriptions and accounts of the
pre-1941 fishery are limited to brief descriptions
provided by Elden Vestal in his written testimony as it
related to Rush Creek. (CT 5.) Mr. Vestal testified that
both Parker Creek and Walker Creek were continuous in
their natural condition, especially during wetter years.
Both of these streams provided important nursery and
breeding areas for Rush Creek, as well as supporting a
local fishery. (CT 5, p. 14.) The descriptions of
pre-1941 conditions on Walker Creek discussed in DFG
Exhibit 56 were collected from documents and transcripts
of proceedings in the El Dorado County Superior Court.
(DFG 56, p. 20, citing Reporter's Transcripts of
proceedings on May 3 and 4, 1990.)
Walker Creek was impacted by grazing and
irrigation prior to the diversion of water for export by
LADWP in 1941. The continued grazing and irrigation
diversions, combined with the export of water beginning
in 1941, severely degraded the aquatic and riparian
environments. Complete diversions of the entire
streamflow for export and irrigation occurred several
months annually. (DFG 56, p. i.)
Walker Creek was planted with fish in the
early 1900s under intermittent flow conditions from
in-basin irrigation practices. The fishery continued to
exist near the confluence with Rush Creek, as water was
maintained in this segment by accretion from springs in
the lower reaches. Brook trout and Lahonton cutthroat
trout were introduced to Walker Creek in 1932 and 1933,
in addition to brown trout, which continued to be planted
in Rush Creek through about 1942. (DFG 56, p. 8.) The
Walker Creek fishery endured until the mid-1950s under
intermittent streamflow conditions. (DFG 56, p. 8.)
There is limited information available
regarding the pre-project fishery that existed on Walker
Creek. The record indicates that Walker Creek supported a
limited trout fishery, the extent of which is unknown.
The fishery may have naturally experienced periodic
dewatering of the main stream channel but fish were able
to move upstream or downstream into Rush Creek as
instream flows subsided.
5.2.2 Instream Flows for Fishery
Protection
DFG prepared the Walker Creek Instream Flow Report 92-1
in cooperation with LADWP. (DFG 56 and DFG 57.) Ebasco
Environmental (Ebasco) of Sacramento was jointly selected
by DFG and LADWP to conduct the investigation. The
purpose of the study was to provide a plan to restore and
optimize the presently degraded aquatic and riparian
environments in lower Walker Creek.
DFG recommended the instream flows shown
in Table 6, to maintain fish in good condition as
required by Fish and Game Code Sections 5937 and 5946,
until the stream reaches dynamic equilibrium and a more
exact evaluation can be conducted. (DFG 3, p. 6.) In
effect, DFG recommends continuation of the flow regime
developed by the El Dorado Superior Court as set forth in
its "Order Setting Interim Flows" dated June
14, 1990. LADWP recommended the same instream flows for
protection of fish in Walker Creek. (LADWP 133, p. 2.)
The recommended minimum flow requirements do not vary
based on dry, normal or wet hydrologic year types. LADWP
and DFG recommend that the minimum instream flow
requirement be the flow specified in Table 6 or the
inflow to the Walker Creek diversion facility, whichever
is less. Based on the evidence presented, the SWRCB
concludes that LADWP's licenses should be amended to
include the minimum instream flow requirements specified
in Table 6 below or the inflow to the Walker Creek
diversion facility, whichever is less.
TABLE 6: WALKER CREEK INSTREAM FLOW REQUIREMENTS*
*All flows are in cubic feet per second (cfs)
5.2.3 Channel
Maintenance and Flushing Flows
DFG presented channel maintenance and flushing flow
recommendations for Walker Creek in DFG Exhibits 56 and
170A. The original recommendation was for 15 to 30 cfs
initially for 1 to 4 days during the snowmelt season.
During wet years flows up to 30 cfs could be released to
provide more flushing. The original recommendation was
later revised to the flows specified in Table 7. (DFG
170A.) The ramping rate applies only if LADWP is
diverting water for export. If LADWP is not diverting
water, flows may fluctuate in accordance with the inflow
to the diversion facility. Based on the evidence provided
in support of the channel maintenance and flushing flows
recommended by DFG, the SWRCB concludes that the evidence
supports adoption of a channel maintenance and flushing
flow requirement for Walker Creek as recommended by DFG
and as specified in Table 7 below.
TABLE 7:
CHANNEL MAINTENANCE AND FLUSHING FLOWS FOR LOWER WALKER
CREEK
|
|
|
|
|
15 to 30 cfs for 1 to 4 days
between May 1 and July 31
|
|
15 to 30 cfs for 1 to 4 days
between May 1 and July 31
|
RAMPING RATE - 10% CHANGE IN STREAMFLOW PER 24 HOURS
|
The ramping requirement applies to
changes in flow made by LADWP.
LADWP is not required to compensate for natural
fluctuations in flow.
5.2.4 Additional Measures to Assist
the Restoration of the Pre-Project Fishery
In 1990, the Walker Creek channel was modified in
anticipation of rewatering pursuant to the Superior Court
order setting interim flows. The modifications included
removal of sediments and sod to increase channel
capacity, closing of irrigation channels, and removal of
channel obstructions such as soils, berms and small loose
woody debris. Restoration of flow to Walker Creek in
October 1990 created a continuous instream flow to the
confluence with Rush Creek. DFG planted approximately 550
hatchery reared brown trout on November 29, 1990. By July
1991, both hatchery and wild brown trout were in Walker
Creek downstream of the LADWP diversion facility. (DFG
56, p. 44.)
The DFG reported that the new
streamflows, along with the use of livestock exclosure
fences to protect riparian areas from grazing, allowed
renewed growth of riparian vegetation which in turn
provided cover and food supplies for fish. (DFG 56, p.
44.) The instream flow recommendation was intended to
provide protective habitat until an instream flow study
could be conducted and optimal flows were in place. The
1992 DFG report states:
"Fish habitat from the conduit
to Rush Creek has been provided for under the present
flow regime (Ebasco Environmental 1991, 1992). This
regime has supported healthy trout and diverse
populations of aquatic invertebrates. Further, summer
water temperatures have been within the optimum range for
trout, and the channel location appeared stable."
(DFG 56, p. 118; DFG 64, p. 75.)
The restoration monitoring of Parker and
Walker Creeks conducted by Ebasco for LADWP documented
the physical and biological condition of these creeks
before and after channel modifications and after
rewatering. (DFG 64, p. 1.) Streamflows in Walker Creek
measured directly below the diversion dam during January
through March, and August through November, ranged from 1
to 13 cfs. During much of the year, flows were below the
6.0 cfs specified in the Superior Court order due to
insufficient flows upstream of the diversion facility.
(DFG 64, p. i.)
The monitoring program concluded that
summer temperatures did not appear to pose a threat to
self-sustaining brown trout populations. Several other
factors may pose a threat to brown trout. These may
include low winter flows and low water temperatures
causing instream icing and the blockage of migration
routes by the LADWP diversion facility, Parshall flumes
and the Highway 395 culvert. Wild fish captured below the
diversion facility indicate recruitment from upstream as
these fish evidently passed through the conduit bypass
pipe. However, the Parshall flumes and the Highway 395
culvert have prevented upstream migration from Rush Creek
beyond those points. (DFG 64, p. 73.)
The Walker Creek study described several
degraded conditions that are considered limiting to the
fishery. (DFG 56.) The primary concern is the need for
stable instream flows. Extensive livestock grazing has
resulted in the loss of a significant amount of the
riparian vegetation and the deterioration of the defined
banks and channels. Dewatering of the main channel for
irrigation stranded fish and deprived the riparian
vegetation of water. Construction and operation of the
diversion facility by LADWP blocked fish migration and
trapped sediments and gravel.
DFG recommends the construction and
operation of a bypass system around the LADWP diversion
facility to restore fish passage, allow sediment and
gravel transport, and to improve benthic drift. The
design of this system should consider restoration of the
contiguous stream condition while maintaining diversion
capabilities. The bypass system should be designed to
prevent the entrapment of fish in the bypass facility and
should be screened to prevent fish from entering the
conduit. (DFG 56, p. 56.) Until the bypass channel
is operational, spawning gravel should be distributed
below the diversion facility to maintain gravel
distribution to downstream areas. (DFG 56, p. 57.)
To reduce entrainment of fish in the
irrigation channels, all diversions should be screened to
prevent fish from entering. To optimize habitat
conditions, DFG recommended locating all intakes for
irrigation at the diversion dam, screening the intake,
and conveying irrigation water to the irrigation channels
via rigid or flexible pipe. Relocating the intakes to the
diversion facility would eliminate the need to operate
and maintain instream diversion structures. (DFG 56, p.
57.)
The SWRCB concludes that Walker Creek is
maintaining a self-sustaining brown trout fishery. The
evidence indicates that the riparian vegetation has shown
considerable improvement since the 1990 rewatering and
the elimination of grazing. Any future revegetation
programs should be based upon evaluation of site-
specific needs. Fish passage is restricted by the
Parshall flumes, the LADWP diversion dam, and the Highway
395 culvert. Fish populations are still low, possibly due
to limited flows available as recovery from drought
continues and due to blockage of upstream and downstream
migration.
The plans described by DFG indicate that
the need for implementing many of the potential
restoration measures depends upon field conditions. Due
to changing land use practices and ongoing restoration
activities such as livestock exclosure fencing, aquatic
and riparian losses are decreasing and the need for some
of the restoration measures recommended in the DFG report
may also decrease. In addition, construction of livestock
exclosure fences and continued instream flows could
increase natural regeneration and reduce the need for
site revegetation. Therefore, the DFG report concludes
that need should be confirmed before implementing
specific recommended restoration measures. (DFG 56, pp.
118-119.)
The evidence in the record supports the
conclusion that, in addition to the flow requirements
discussed above, the following other measures should be
undertaken to restore and maintain in good condition the
fishery that existed in Walker Creek prior to the
diversion of water by LADWP:
1. A fish and sediment bypass system
should be constructed around the Walker Creek diversion
facility.
2. Livestock grazing should be prohibited
within the lower Walker Creek riparian corridor
downstream of the LADWP diversion point for a minimum of
ten years from the date of this order. Any resumption of
grazing in the future should be subject to approval by
the Chief of the Divsion of Water Rights of a plan
prepared by LADWP in consultation with DFG.
3. Minimum flows released to maintain the
fishery should remain in the stream channel and should
not be diverted for any use other than maintenance of the
Walker Creek fishery.
4. Spawning gravel should be distributed
below the LADWP Walker Creek diversion facility until
such time as the bypass stream has become operational.
5. If LADWP continues irrigation from
Walker Creek, then all irrigation facilities should be
constructed and operated in a manner that does not not
impede fish passage and screened to prevent fish from
becoming stranded in irrigation channels.
6. Vegetation disturbed by construction
for any of the restoration activities required by this
decision should be restored and revegetation should
commence as soon as construction activities have been
completed.
7. LADWP should consult with DFG
regarding the revegetation that may be necessary to
maintain fish in good condition in Walker Creek.
8. LADWP should install and maintain
continuous recording devices satisfactory to the Chief of
the Division of Water Rights to measure the streamflow
above the Walker Creek diversion facility and the flow
immediately below the diversion facility.
The installation of a continuous flow
recording device and the prohibition of grazing in the
riparian corridor can be implemented without the need for
a lengthy planning period. The other measures specified
above should be addressed in the stream restoration plan
to be prepared under the provisions of this decision.
5.3 Parker Creek
Pre-Project Conditions
As in the case of Walker Creek, relatively little
evidence was presented regarding pre-1941 conditions on
Parker Creek. DFG's recommendations for instream flows
and restoration measures for Parker Creek are presented
in the Parker Creek Stream Evaluation Report 92-2,
Volumes 1 and 2, dated December 1992, prepared by Ebasco
Environmental. (DFG 58 and DFG 59.)
Prior to the diversion of water by LADWP
in 1941, Parker Creek supported a trout fishery. The
riparian corridor was typically willow thickets and
deciduous hardwood forest. Ebasco used 1929 aerial
photographs to determine the extent of the pre-diversion
riparian corridor. These photographs were compared to
1990 aerial photographs to determine the gains or losses
in the riparian corridor following the start of water
diversions by LADWP.
The pre-1941 aquatic environment was
degraded by extensive livestock grazing and water
diversions for irrigation. (DFG 58, pp. 1-3; LADWP 9,
Section 2 pp. 21-22.) Prior to 1941, Parker Creek was
planted with brown trout, Lahonton cutthroat trout and
brook trout. The fishery continued to exist with
intermittent flow conditions through the 1950s. (DFG 58,
p. 8.) Parker Creek was rewatered in 1990, and shortly
thereafter it was stocked with brown trout by DFG.
5.3.2 Instream Flows for Fishery
Protection
DFG prepared the Parker Creek Instream Flow Report 92-2
in cooperation with LADWP. (DFG 58.) Ebasco Environmental
(Ebasco) of Sacramento was jointly selected by DFG and
LADWP to perform the investigation. The objectives of the
study were to develop a plan to restore and optimize the
degraded aquatic and riparian environments of lower
Parker Creek. From 1940 to 1990, the streamflow was
diverted at the LADWP diversion facility, and the
downstream channel remained dewatered for several months
annually (DFG 58, p. i.) Except during periods of very
high natural runoff or local irrigation, the annual
dewatering of Parker Creek eliminated both aquatic
habitats and biological resources, and desiccated
riparian habitats. (DFG 58, p. 2.)
DFG recommended the instream flows shown
in Table 8 to maintain fish in good condition as required
by Fish and Game Code Section 5937 until the stream
reaches dynamic equilibrium and a more exact evaluation
can be conducted. (DFG 3, p. 6.) LADWP recommended the
same instream flows as DFG. (LADWP 133, p. 2.) As in the
case of Walker Creek, the minimum flows recommended by
DFG are the same as the minimum flows required by the El
Dorado Superior Court in its "Order Setting Interim
Flows" dated June 14, 1990. The recommended
flow requirements do not vary based on dry, normal or wet
hydrologic year types. LADWP and DFG recommend that the
minimum flow requirements be the flow specified in Table
8 below or the inflow to the Parker Creek diversion
facility, whichever is less. Based on the evidence
presented, the SWRCB concludes that LADWP's licenses
should be amended to include the minimum instream flow
requirements specified in Table 8 or the inflow to the
Parker Creek diversion facility, whichever is less.
TABLE 8:PARKER CREEK INSTREAM FLOW REQUIREMENTS*
*All flows are in cubic feet per second (cfs)
5.3.3 Channel
Maintenance and Flushing FlowsDFG presented its
initial channel maintenance and flushing flow
recommendations for Parker Creek in DFG Exhibits 3 and
58. The original recommendation of 25 to 40 cfs for one
to four days each year was later revised to the flows
specified below in Table 9. (DFG 170A.) The ramping rate
applies only if LADWP is diverting water for export. If
LADWP is not diverting water, flows may fluctuate in
accordance with the inflow to the diversion facility. If
LADWP is diverting water, the ramping rate shall be a 10
percent change in streamflow per 24 hours. (DFG 170A.)
Based on the evidence provided in support of the channel
maintenance and flushing flows recommended by DFG, the
SWRCB concludes that the evidence supports adoption of a
channel maintenance and flushing flow requirement for
lower Parker Creek as recommended by DFG and as specified
in Table 9 below. (DFG 168 and 170A.)
TABLE 9: CHANNEL MAINTENANCE AND FLUSHING FLOWS FOR
LOWER PARKER CREEK
|
|
|
|
|
25 to 40 CFS FOR 1-4 DAYS
BETWEEN MAY 1 AND JULY 31
|
|
25 to 40 CFS FOR 1-4 DAYS
BETWEEN MAY 1 AND JULY 31
|
RAMPING RATE - NOT TO EXCEED A 10% CHANGE IN STREAMFLOW PER 24 HOURS
|
The
ramping requirement applies to changes in flow made by
LADWP. LADWP is not required to compensate for natural
fluctuations in flow.
5.3.4 Additional Measures to Assist
the Restoration of Pre-Project Fishery
In 1990, the Parker Creek channel was modified in
anticipation of rewatering pursuant to the Superior Court
order setting interim flows. The modifications included
removal of sediments and sod, closing of irrigation
diversion channels, and removal of channel obstructions
such as the Parker Plug, soils, berms and small loose
woody debris. Restoration of flows to Parker Creek in
October of 1990 created a continuous instream flow to the
confluence with Rush Creek. DFG planted brown trout in
Parker Creek below the LADWP diversion facility on
November 29, 1990 and August 8, 1991. (DFG 58, p. 45.)
DFG reported that the new streamflows, along with the use
of livestock exclosure fences to protect riparian areas
from grazing, allowed renewed growth of riparian
vegetation which in turn has provided cover and food
supplies for fish.
The Parker Creek report describes various
degraded conditions which could be limiting for the
fishery. The primary concern is the need for stable
instream flows. Extensive livestock grazing resulted in
the loss of much of the riparian vegetation and the
deterioration of the defined banks and channels.
Irrigation also added to the degradation of Parker Creek
by dewatering the main channel and stranding fish. (DFG
58.)
The channel modifications completed prior
to the rewatering of Parker Creek in 1990 improved the
aquatic and riparian habitat. However, if some of the
stable woody debris had not been previously removed as
part of that process, it would have created fish habitat
structures upon rewatering. (DFG 58, p.119.) Natural
recovery of the aquatic and riparian habitat was apparent
in 1991, approximately one year after the channel had
been rewatered. Nevertheless, degradation of aquatic
habitat remained due to a number of factors. Among the
problems identified in the DFG report was trapping of
sediment (including spawning gravels) at the diversion
facility, and possible entrainment of fish at the
diversion conduit. The conduit diversion dam, Parshall
flumes and the Highway 395 culvert remain as barriers to
fish migration. (DFG 58, p. 119.)
The restoration monitoring of Parker and
Walker Creeks conducted by Ebasco for LADWP documented
the physical and biological condition of these streams
before and after channel modifications, and after
rewatering. (DFG 64, p. 1.) Mean daily streamflows
between November 19, 1990 and October 31, 1991 downstream
of the Parshall flume on Parker Creek ranged from 0.5 to
30.9 cfs. During much of the year, flows were below the
9.0 and 6.0 cfs specified in the Superior Court order due
to insufficient flows upstream of the diversion facility.
(DFG 64, p. 51.)
The Ebasco monitoring program concluded
that there is some recruitment of wild fish from the
upstream population to lower Parker Creek. The Parshall
flume and the Highway 395 culvert have inhibited upstream
movement of fish from Rush Creek into Parker Creek beyond
those structures. (DFG 64, p. 73.) The fish populations
were sampled in lower Parker Creek in 1991. The results
indicated an absence of hatchery reared trout and a low
number of wild trout. (DFG 64, p. 63 Table 3-11.) There
is some evidence that low winter flows in Parker Creek in
combination with low water temperatures may have led to
development of instream ice conditions reducing the
survival of hatchery fish planted in Parker Creek in
1990. (DFG 64, p. 73.) Monitoring of water temperatures
in Parker Creek indicated that mean daily temperatures
did not exceed 15.5o C, and the highest
maximum temperature recorded is 17.50C which
is below the upper limit of the optimal temperature range
for brown trout of 19.00 C. (DFG 64, p. 60,
Table 3-10; DFG 64, p. 73.)
DFG recommends the construction and
operation of a bypass system around the LADWP diversion
facility to restore fish passage and allow sediment
bypass. The design of this system should consider
restoration of the contiguous stream condition while
maintaining diversion capabilities. The bypass system
should be designed to prevent the entrapment of fish in
the bypass facility and should be screened to prevent
fish from entering the conduit. (DFG 58, p. 57.) DFG also
recommends removal of fish migration barriers and
revegetation for areas not experiencing natural habitat
recovery. (DFG 58, p. 119.)
As in the case of Walker Creek, DFG
advises that the need for implementing many of the
restoration measures it has identified depends upon field
conditions. Due to changing land use practices and
ongoing restoration activities such as livestock
exclosure fencing, aquatic and riparian losses are
decreasing and the need for some of the restoration
measures recommended in the DFG plan may also decrease.
DFG also advises that construction of livestock exclosure
fences and continuation of instream flows could increase
natural regeneration and reduce the need for site
revegetation. Therefore, the DFG report concludes that
need should be confirmed before implementing specific
recommended restoration measures. (DFG 58, pp. 118-119.)
Based on the evidence presented, the
SWRCB concludes that Parker Creek supported a brown trout
fishery prior to the export of water by LADWP. Although
extensive grazing existed in the riparian corridor, the
riparian corridor was more extensive than that which
exists today. Natural recovery has begun since the
rewatering of Parker Creek was required by court order in
1990. Restoration activities such as removal of the
Parker plug, channel modification prior to rewatering,
livestock exclosure fences, maintenance of continuous
streamflows and planting of brown trout have resulted in
a significant improvement of the aquatic and riparian
habitat. The evidence in the record supports the
conclusion that, in addition to the flow requirements
specified above, the following measures should be
undertaken to restore and maintain in good condition the
fishery as it existed in Parker Creek prior to the
diversion of water by LADWP:
1. A fish and sediment bypass system
should be constructed around the Parker Creek diversion
facility.
2. Livestock grazing should be prohibited
within the Parker Creek riparian corridor downstream of
the LADWP diversion point for a minimum of ten years from
the date of this order. Any resumption of grazing in the
future should be subject to approval by the Chief of the
Divsion of Water Rights of a plan prepared by LADWP in
consultation with DFG.
3. Minimum flows released to maintain the
fishery should remain in the stream channel. No diversion
or use of this water should be authorized for any use
other than maintenance of the Parker Creek fishery.
4. Spawning gravel should be distributed
below the LADWP Parker Creek diversion facility until
such time as the bypass stream has become operational.
5. If LADWP continues irrigation from
Parker Creek, then all irrigation facilities should be
constructed and operated in a manner that does not not
impede fish passage and screened to prevent fish from
becoming stranded in irrigation channels.
6. Vegetation disturbed by construction
for any of the restoration activities required by this
order should be restored and revegetation should commence
as soon as construction activities have been completed.
7. LADWP should consult with DFG
regarding revegetation that may be necessary to maintain
fish in good condition in Parker Creek.
8. LADWP should install and maintain
continuous recording devices satisfactory to the Chief of
the Division of Water Rights to measure the streamflow
above the diversion facility and the flow immediately
below the diversion facility. Installation of a
continuous flow recording device and the prohibition of
grazing in the riparian corridor can be implemented
without need for a lengthy planning period. The other
measures specified above should be addressed in the
stream restoration plan required to be prepared under the
provisions of this decision.
5.4 Rush Creek
Pre-Project Conditions
Rush Creek is the largest tributary to Mono Lake.
Numerous reports were submitted in these proceedings
concerning stream and riparian conditions on Rush Creek
prior to the diversion of water by the City of Los
Angeles. (e.g., SWRCB 7; NAS&MLC 123, 125, 126, 133,
134, 136, 137, 264, and 265; CT 1, 5, 5B, 5S, and 8; and
LADWP 1, 4, 7, 9, 15, 17, 19, 21, 43, 132, 136, 137, et
al.) Trihey and Associates summarized a number of these
documents in an attempt to describe the pre-1941
conditions on Rush Creek. (NAS&MLC 137.) The majority
of the descriptions of the pre-project fishery are either
the direct account of Elden Vestal or they reference his
testimony in the Superior Court or material he prepared
for this proceeding.
Mr. Vestal's testimony indicates he was
familiar with the Rush Creek fishery as it existed prior
to the diversion of water by LADWP in 1941. His
experience included a Test Stream Study on Rush Creek,
review of the fish planting records for the region, and
his overall experience in the Mono Basin. (CT 5, p. 8.)
Mr. Vestal described DFG's activities, including hatchery
and egg collection operations on Rush Creek. (CT 5F, 5G.)
He also described the type and quantities of fish that
were present prior to 1941, testifying that "...Rush
Creek produced among the largest and hardiest trout in
the region." (CT 5, p. 11.) DFG began planting brown
trout in the 1930s in response to local angling pressure.
Mr. Vestal indicated that he regularly observed brown
trout, averaging 13 to 14 inches, in lower Rush Creek.
Rush Creek was a popular fishing attraction from the
1920s through the 1940s because of the quality fishing.
Dr. Beschta testified that pre-project
stream and riparian conditions on Rush Creek were similar
to those summarized by Trihey and Associates. (LADWP 9,
p. 137.) His testimony differed with regard to the
effects of irrigation practices, grazing, the physical
description of the stream channel and the riparian
vegetation. Based on his interpretation of historic
photographs and field observations, Dr. Beschta concluded
that Rush Creek occupied a sinuous single thread channel
throughout most of its length with channel widths of 30
feet or less and pools likely to occur at meander bends
or where flows interacted with the root masses of mature
streamside vegetation. Dr. Beschta believes that changes
in channel pattern below Indian Ditch indicate grazing
was causing the channel to widen and shallow. Dr.
Beschta's written testimony states that the general
braiding of the channel and reduced streamside vegetation
are definite indicators of channel instability, widening,
and shallowing. (LADWP 137, p. 4.) Dr. Beschta believes
that the multi-channels were mostly irrigation ditches
and overflow channels which were not watered throughout
the year.
Prior to export of water from the Mono
Basin, water diverted for irrigation onto both sides of
the bottomlands assisted in maintaining high densities of
woody plants away from the main channel. The water
diverted for irrigation or subsurface seepage caused the
occurrence of several ponded areas alongside Rush Creek
downstream of the Narrows. (LADWP 137, p. 4.) Extensive
grazing pressure had caused significant changes to
understory plants but the overstory remained intact.
Channel banks and water quality had been impacted by
livestock grazing, but widespread channel changes had not
yet occurred. From the Narrows downstream to the Indian
Ditch diversion, there were long, smooth meanders. (LADWP
137, p. 1.)
Anglers considered Rush Creek to be a
very good trout stream, producing trout weighing 3/4 to 2
pounds fairly consistently. Aquatic and riparian habitat
conditions differed considerably above and below the
Narrows. The Narrows is a granitic dike crossing Rush
Creek approximately midway between Grant Lake and Mono
Lake. (NAS&MLC 125, p. 16.)
For study purposes, Mr. Trihey divided
Rush Creek below Grant Lake into 5 segments: segments 1,
2 and 3 above the Narrows and segments 4 and 5 below the
Narrows. Prior to LADWP's diversions, small clusters of
Jeffery Pine grew along the stream corridor and a
continuous ribbon of willow and cottonwood extended along
much of the corridor from the historic Grant Lake to the
Narrows. The riparian vegetation directly below Grant
Lake (segment 2) has changed little since 1940. Prior to
1941, this segment had some streamflow during all months
except during extreme drought winter periods. Seepage and
ponded water in the historic Grant Lake and forebay
prevented the channel from becoming entirely dry.
(NAS&MLC 122.)
The upper portion of segment 3 also
remained flowing most of the time. A small amount of
water was contributed from seepage from A-Ditch and South
Parker Creek. The middle reach of segment 3 was at times
dry below B-Ditch to the confluence of Parker Creek. The
lower segment 3 remained flowing most of the time gaining
water from springs, and Parker and Walker Creeks,
although very little contribution came from Parker and
Walker Creeks during the irrigation season. The upper
portion of segment 3 consisted of dense willows
interspersed with pine trees. Also present were several
cutoff meander bends and secondary channels. This area
probably provided good habitat for fish. In addition, the
secondary channels probably contributed to a reduction in
streambed and streambank scouring during periods of high
runoff by shunting a portion of the flood flow out of the
main channel and onto a floodplain. It is uncertain
whether or not these channels remained watered outside of
the high flow period. (NAS&MLC 125, p. 17.)
In segment 4 downstream of the Narrows,
Rush Creek opens into a broad, flat floored valley called
the "bottomlands". Dr. Stine testified that the
bottomlands were characterized by a wide and dense
riparian corridor, wooded marshlands, wet meadows, ponded
water, abundant springs and a system of narrow,
steep-sided, low-gradient perennial channels.
(NAS&MLC 1W.) The spring flow in the bottomlands was
a combination of natural and artificially induced flows
resulting from irrigation on the Cain Ranch and in the
Pumice Valley with an average annual application of
30,000 acre-feet. The spring systems and the natural high
water table supported dense stands of riparian
vegetation. (NAS&MLC 122.) Mr. Vestal reported that
springs provided lush watercress beds that produced
important trout foods. (CT 5, p. 14.)
In segment 5, which is below the meadows
described in segment 4, little if any spring flow
occurred. Dikes had been constructed between the County
Road and Mono Lake. The dikes formed ponds and freshwater
marshy areas. These ponds provided habitat for large
brown trout and waterfowl. (DFG 137.) The fish and
wildlife habitat provided by these ponds was present only
because of the construction of dikes to store water.
Segments 4 and 5 remained flowing most of
the time. Water was contributed from springs, Parker and
Walker Creeks and some irrigation return flow. The flow
in many of the auxiliary channels was supported by return
flow from irrigation and subterranean contribution from
springs. (NAS&MLC 122.)
Prior to 1941, healthy stands of
vegetation were commonly found along all reaches of Rush
Creek. The riparian zone was generally characterized by a
dense multilayered canopy of trees, shrubs and herbaceous
plants. Approximately 271 acres of woody vegetation and
131 acres of meadows were present along Rush Creek in
1940. Prior to the export of water by LADWP, there were
only localized impacts to riparian vegetation. The area
around B-Ditch and the old Highway 395 crossing was
degraded from construction of the highway and/or
construction of B-Ditch. (NAS&MLC 122 and 137,
p. 5-1.)
Based on the evidence in the record, the
SWRCB concludes that the pre-1941 fishery in Rush Creek
was predominately a self-sustaining brown trout fishery
with some rainbow trout present. In the 1930s through the
1940s, the fishery was augmented with planted fish to
offset heavy fishing pressure. The fisheries above and
below the Narrows were considerably different. The
grazing and irrigation practices in the area above the
Narrows had degraded the habitat considerably. Lower Rush
Creek also experienced damage from grazing and limited
water supply, but maintained a higher quality fishery.
5.4.2 Flows for Providing Fishery
Habitat
DFG submitted DFG Exhibits 52 and 53, Rush Creek Stream
Evaluation Report 91-2, Volumes 1 and 2, which were
prepared by Beak Consultants, Inc. (Beak) as a
cooperative study funded by LADWP and DFG. This report is
based on a comprehensive investigation which used the
instream flow incremental methodology (IFIM) to determine
instream flow requirements for brown trout in Rush Creek,
based on fieldwork done in 1987. The study was comprised
of investigative elements designed to identify instream
flow needs and to provide a basis for flow
recommendations. Flow recommendations were based upon
habitat availability and historic flow, and were modified
on the basis of stream channel stability and streambed
mobility. Table 34 of the report presents flow
recommendations for brown trout in lower Rush Creek
during dry, normal and wet hydrologic years. (DFG 52, p.
107, Table 34.)
DFG's instream flow recommendations in
this proceeding are set forth in an addendum to the
report which presents revised instream flow
recommendations for Rush Creek. (DFG 52, Addendum to
"Instream Flow Requirements for Brown Trout, Rush
Creek, Mono County, Volume 1," California Department
of Fish and Game Stream Evaluation Report 91-2.) The
written testimony of Gary Smith explains DFG's rationale
for revising the instream flow recommendations in the
Beak report. (DFG 3, p. 3.) Mr. Smith explained that,
prior to the publication of the 1991 report, a trout
spawning gravel replenishment program was implemented on
Rush Creek by the Rush and Lee Vining Creeks Habitat
Restoration Technical Committee. In view of the gravel
replenishment program, Mr. Smith testified that an upper
limit of 60 cfs on recommended flows was no longer
applicable. He went on to state that he used the
information found in Tables 33 and 34 of DFG Exhibit 52,
to develop revised instream flow regimes for releases at
Mono Gate One for dry, normal and wet hydrological
conditions, as shown in the addendum to the report. (DFG
3; DFG 52, pp. 105 and 107, Tables 33 and 34.) The
primary difference is that the revised recommendation
proposes higher flows for the months of May through
September, in excess of the initial recommendation of 60
cfs for that period.
LADWP submitted two instream flow
recommendations for Rush Creek. The initial
recommendation was presented in the original LADWP Mono
Lake Management Plan. As discussed in Section 5.1.1
above, the LADWP plan was revised and a new instream flow
recommendation was presented which includes the minimum
flows for the fishery and additional flows to protect
Mono Lake. (LADWP 133, p. 2, Table 1).
Table 10 below shows the various instream
flow recommendations for Rush Creek presented during the
SWRCB proceedings, in addition to the interim flows
established by the El Dorado County Superior Court and
the flow requirements established in this decision. The
flows represented in the column labeled "Beak"
are the flow recommendations described in DFG Exhibit 52.
(DFG 52, p. 107, Table 34.) The flow recommendations in
the column labeled "DFG" are DFG's present
recommendations as shown in the addendum to DFG Exhibit
52 and as described in DFG Exhibit 3. LADWP's original
flow recommendations are shown in the column labelled
"LADWP," and their revised recommendations are
shown in the column labelled "LADWP Revised."
(LADWP 53, Section 2, p. 38; LADWP 133, p. 2, Table
1.) The interim flows set by the Superior Court are shown
in the last column of the Table 10, and the flow
requirements established in this decision are shown in
the column labelled "SWRCB."
TABLE 10: RUSH CREEK
INSTREAM FLOW RECOMMENDATIONS/REQUIREMENTS*
HYDRO-
LOGIC
YEAR
|
MONTH
|
BEAK
|
DFG
|
SWRCB
|
LADWP
|
LADWP
REVISED
|
INTERIM
|
DRY
|
APRIL
|
35
|
35
|
31
|
30
|
30
|
40
|
|
MAY
|
60
|
75
|
31
|
30
|
35
|
40
|
|
JUNE
|
60
|
72
|
31
|
30
|
40
|
40
|
|
JULY
|
45
|
45
|
31
|
30
|
40
|
40
|
|
AUGUST
|
42
|
42
|
31
|
30
|
35
|
40
|
|
SEPTEMBER
|
40
|
40
|
31
|
30
|
30
|
40
|
|
OCTOBER
|
36
|
36
|
36
|
20
|
25
|
28
|
|
NOVEMBER
|
30
|
30
|
36
|
20
|
25
|
28
|
|
DECEMBER
|
30
|
30
|
36
|
20
|
25
|
28
|
|
JANUARY
|
31
|
31
|
36
|
20
|
25
|
28
|
|
FEBRUARY
|
32
|
32
|
36
|
20
|
25
|
28
|
|
MARCH
|
34
|
34
|
36
|
20
|
25
|
40
|
NORMAL
|
APRIL
|
59
|
59
|
47
|
30
|
30
|
40
|
|
MAY
|
60
|
100
|
47
|
30
|
35
|
40
|
|
JUNE
|
60
|
100
|
47
|
30
|
40
|
40
|
|
JULY
|
60
|
100
|
47
|
30
|
40
|
40
|
|
AUGUST
|
60
|
93
|
47
|
30
|
35
|
40
|
|
SEPTEMBER
|
60
|
69
|
47
|
30
|
30
|
40
|
|
OCTOBER
|
58
|
58
|
44
|
20
|
25
|
28
|
|
NOVEMBER
|
40
|
40
|
44
|
20
|
25
|
28
|
|
DECEMBER
|
40
|
40
|
44
|
20
|
25
|
28
|
|
JANUARY
|
44
|
44
|
44
|
20
|
25
|
28
|
|
FEBRUARY
|
48
|
48
|
44
|
20
|
25
|
28
|
|
MARCH
|
52
|
52
|
44
|
20
|
25
|
40
|
WET
|
APRIL
|
60
|
84
|
68
|
30
|
30
|
40
|
|
MAY
|
60
|
100
|
68
|
30
|
35
|
40
|
|
JUNE
|
60
|
100
|
68
|
30
|
40
|
40
|
|
JULY
|
60
|
100
|
68
|
30
|
40
|
40
|
|
AUGUST
|
60
|
100
|
68
|
30
|
35
|
40
|
|
SEPTEMBER
|
60
|
100
|
68
|
30
|
30
|
40
|
|
OCTOBER
|
60
|
93
|
52
|
20
|
25
|
28
|
|
NOVEMBER
|
56
|
71
|
52
|
20
|
25
|
28
|
|
DECEMBER
|
56
|
71
|
52
|
20
|
25
|
28
|
|
JANUARY
|
57
|
57
|
52
|
20
|
25
|
28
|
|
FEBRUARY
|
54
|
54
|
52
|
20
|
25
|
28
|
|
MARCH
|
54
|
54
|
52
|
20
|
25
|
40
|
*All
flows are in cubic feet per second (cfs)
Mr. Trihey suggested that with
a range of streamflows from 30 to 100 cfs (DFG's
recommendation) the treatments that are in place will
work well. Channel flushing and maintenance flows of 350
cfs would result in minimal erosion of streambed and
banks. He also indicated that opening up the historic
channels would lessen the erosive effects, and that the
reemergence of riparian vegetation would solidify the
channel and provide good refuge habitat for fish during
overbank flows, thus allowing even higher flows without
injury to the fishery. (NAS&MLC 1X, p. 12.)
The instream flow recommendations
developed by DFG were characterized as providing for the
maintenance of the brown trout population in lower Rush
Creek. Instream flow recommendations were based on the
goal of attempting to maintain the median ("50%
exceedence") brown trout habitat that would occur in
lower Rush Creek, for each of three hydrologic year
types, in the absence of water storage and diversion at
Grant Lake. (DFG 52, p. 103.) DFG Exhibit 52 suggests
that maintenance of median habitat for brown trout will
maintain the fish population.
Initially, DFG's use of median values for
flow recommendations was modified to respond to the
concern that the transport of spawning size substrate
will begin at 60 cfs thus reducing spawning habitat if
flows were in excess of 60 cfs. The Beak study
recommended restricting flows to 60 cfs to avoid
potential uncompensated losses of spawning size substrate
in reaches 2 and 3. (DFG 52, p. 106.) In addition,
in order to restrict the exposure of redds (trout
spawning nests), DFG limited the reduction of flows
during the spawning period by averaging the median flows
recommended for those months. Additional modification of
the median flow recommendations was made in an effort to
mimic the seasonal flow regime of water entering Grant
Lake. Water temperature was determined not to be a
limiting factor for the range of flows from 19 cfs to 100
cfs. Consequently, water temperature was not used as a
criterion in developing DFG's flow recommendations.
DFG utilized different criteria for
developing instream flow recommendations for Rush Creek
than were used for Lee Vining Creek. In the case of Rush
Creek, DFG's consultants selected instream flows which
would provide median habitat values for each year type
based on historic inflow to Grant Lake. For Lee Vining
Creek and the Upper Owens River, however, DFG's
consultants based their recommendations on flows needed
to provide a specified percentage of the maximum habitat
available. (RT XX 48:1-49:20; DFG 62, pp. 213-214.) When
asked to explain the reason for the different approaches,
Mr. Smith responded that:
"...the major difference between
Rush and Lee Vining Creeks is the presence of Grant
Reservoir. There is an ability to capture runoff in that
lake and meter it out sometime in the future. That
ability does not exist on Lee Vining Creek. If the
habitat duration approach had been used on Lee Vining
Creek, there would be no mechanism, to maintain the
median habitat discharge." (RT XX, 48:2-48:12.)
DFG's original instream flow
recommendation for Rush Creek would have required the
release of water stored in Grant Lake whenever inflow to
Grant Lake is less than the recommended minimum flows.
During rebuttal testimony, however, Mr. Smith explained
that DFG's revised recommendations would require LADWP
to:
"...release the numerical flows
listed in the Rush Creek addendum for wet and normal
water runoff years, until such time the inflow to Grant
Lake drops below the recommended values. And at that time
the inflow would equal the recommendation. Our
recommendation is that the inflow equal the outflow.
Until the dry runoff year recommendations are reached, at
which time we would recommend that storage be released to
maintain dry year runoff flows, regardless of...runoff
year type." (RT XXXIX, 8:24-9:12.)
The use of different types of criteria to
develop instream flow recommendations for Rush Creek and
Lee Vining Creek was based upon the assumption that LADWP
would be required to release water from storage at Grant
Lake if needed to meet the required flows. DFG's present
proposal, however, would not require release of water
from storage in Grant Lake, except to meet dry-year flow
requirements.
In view of the limited role which release
of stored water from Grant Lake would play in meeting
DFG's revised flow recommendations, it is more
appropriate to determine instream flow requirements for
Rush Creek based on a percentage of available habitat as
was done for Lee Vining Creek. Therefore, as in the case
of Lee Vining Creek, the instream flow requirements for
Rush Creek established in this decision are based upon
the percentage of maximum measured habitat for the life
stages of primary concern, as determined from the amount
of Weighted Useable Area (WUA) at different flows. (RT
XX, 48:1-49:20.)
There is general agreement that adult
habitat and spawning habitat in Rush Creek are limiting.
Thus, it is important to target these two life stages in
establishing instream flow requirements. (DFG 52; LADWP 1
and 130; NAS&MLC 1X.) In order to ensure that
instream flows provided for certain life stages do not
cause severe reductions in available habitat for other
life stages, it is also important to compare the effects
on fry and juvenile habitat of flows designed to maintain
adult and spawning habitat.
In the Lee Vining Creek and the Upper
Owens River DFG studies, the maximum WUA for each of the
targeted life stages were reached at a value below the
highest simulated flow. This was also the case for the
Rush Creek DFG study with the exception of adult habitat
WUAs. The WUA for adult brown trout in Rush Creek
continued to increase at the highest simulated flow of
100 cfs. A comparison of the adult habitat types
indicates the Mono Gate One return channel was the
greatest contributor of adult WUAs in the study area at
flows above 45 cfs. (DFG 52, p. 43.) Extrapolation for
adult habitat at flows above 100 cfs indicates a
continued increase of adult habitat in the return
channel. However, adult habitat in other reaches of the
Rush Creek study peaks and begins to decline at simulated
flows below 100 cfs. (DFG 52, pp. 41-45.)
Thus, the relationship between WUA and
flow in the return channel is not consistent with the
relationship between flow and WUA in a natural channel.
The return channel did not exist in 1941. In establishing
flow requirements intended to restore and maintain the
pre-1941 fishery, it is appropriate to consider the
relationship between WUA and flow in the natural stream
channel. Consequently, the SWRCB bases its flow
requirements upon the assumption that the maximum WUA for
adult brown trout occurs at a flow of 100 cfs.
The criteria DFG applied in determining
flows in Lee Vining Creek were that the targeted life
stages should be provided 80 percent of the maximum WUAs
during dry hydrologic years, 90 percent during normal
hydrologic years and 100 percent during wet hydrologic
years. Similarly, in developing flow requirements for
Rush Creek, this decision sets flow requirements for each
year type based on percentages of the maximum WUAs
available for the limiting life stages of Brown trout in
Rush Creek. The percentages of WUA were derived from the
data developed in the DFG study. (DFG 52, p. 41,
Table 13.)
DFG's recommended flows for April through
September of dry hydrologic years are based on providing
habitat for the adult life stage. The recommended flows
range from 35 cfs in April, peak at 75 cfs in May, and
descend monthly to 72 cfs, 45 cfs, and 42 cfs, continuing
down to 40 cfs in September. A flow of 35 cfs provides 84
percent and 75 cfs provides 96 percent of the maximum WUA
for the adult life stage in lower Rush Creek. Using the
criteria DFG applied to Lee Vining Creek, it is desirable
to provide a minimum of 80 percent of the maximum WUA for
the adult life stage during dry year conditions.
Providing 80 percent of maximum WUA for adult brown trout
corresponds to a flow of 31 cfs in Rush Creek for the
months of April through September. Table 11 below
shows the measured WUA values present for adult brown
trout in Rush Creek at various flows.
TABLE 11:
ADULT BROWN TROUT WEIGHTED USEABLE AREA (WUA) FOR RUSH
CREEK
WUA SQ.FT.
|
CFS
|
PERCENTAGE
|
208,477
|
100
|
100%
|
198,053
|
68
|
95%
|
187,630
|
47
|
90%
|
166,782
|
31
|
80%
|
145,934
|
23
|
70%
|
The DFG spawning flow recommendations
target the months of October through December and range
from 30 cfs to 36 cfs. A flow rate of 30 cfs corresponds
to approximately 71 percent of maximum WUA and 36 cfs
corresponds to 80 percent of the maximum WUA for
spawning. Therefore, providing 80 percent of the maximum
WUA for spawning would require a flow of 36 cfs for
October through December. In order to protect redds and
emerging fry, the minimum flows in effect during the
spawning period of October through December should also
remain in effect during January through March.
TABLE 12:
BROWN TROUT SPAWNING HABITAT WEIGHTED USEABLE AREA (WUA)
RUSH CREEK
WUA SQ.FT.
|
CFS
|
PERCENTAGE
|
69,112
|
85
|
100%
|
65,656
|
52
|
95%
|
62,200
|
44
|
90%
|
55,289
|
36
|
80%
|
48,378
|
29
|
70%
|
Based on the above analysis, the SWRCB
concludes that the minimum flow requirement for dry
hydrologic years on Rush Creek should be 31 cfs for the
months of April 1 through September 30 and 36 cfs from
October through March. The dry year minimum flow
requirements shall be be maintained, if necessary, by
releases from storage until such time as the quantity of
water in storage at Grant Lake declines to 11,500
acre-feet. Any time that Grant Lake storage falls below
11,500 acre-feet (See Section 6.5 "Recreation")
the instream flow requirement will revert to the dry year
flow requirement or the inflow to Grant Lake, whichever
is less.
The DFG recommended instream flow for
Rush Creek during normal hydrologic conditions for the
months of April through September ranges from 59 cfs to
100 cfs. A flow of 59 cfs corresponds to approximately 91
percent of the maximum WUA for adults and 100 cfs
corresponds to 100 percent of the maximum WUA for adults.
Applying the criteria utilized for Lee Vining Creek for
this period (i.e., providing 90 percent of the maximum
WUA) would result in a minimum flow of 47 cfs from April
through September. Maintaining approximately 90 percent
of the maximum WUA for spawning would require a flow of
44 cfs during the period of October through December. In
order to protect redds and emerging fry, the minimum flow
requirement should remain at 44 cfs from January through
March.
Based on the analysis above, the SWRCB
concludes that the minimum instream flow requirement for
the protection of fish in Rush Creek during normal
hydrologic years should be 47 cfs for the period April 1
through September 30 and 44 cfs for October 1 through
March 31, or the inflow to Grant Lake, whichever is less.
During wet hydrologic years, DFG's
recommended instream flows for Rush Creek are 84 cfs
during the month of April, and 100 cfs for May through
September. As discussed earlier in this section, the 100
cfs requirement was based upon the adoption of a gravel
augmentation project by the Restoration Technical
Committee. The Beak report indicates that flow in excess
of 60 cfs may result in scouring and transporting
spawning substrate through the system which would further
reduce spawning habitat. (DFG 52, p. 106.) Mr. Smith
testified, however, that following the gravel
replenishment program established by the Restoration
Technical Committee, the 60 cfs restriction was no longer
applicable. (DFG 3, p. 3.)
At the time of the hearing, DFG had no
information if the gravel replenishment program had
worked, how often it would be necessary to add gravel, or
how a monitoring program would be developed to evaluate
the success of the gravel augmentation program. (RT XX,
72:21-75:9.) DFG did, however, recommend a monitoring
program to evaluate the spawning gravel condition. (RT
XX, 74:18-75:4.) Without a full understanding of the
effects of 100 cfs on spawning substrate and what is
required to implement a successful spawning gravel
augmentation program, it would be inappropriate to
require minimum flows for fishery protection which could
reduce available spawning habitat.
Further, the Beak study (DFG 52 and 53)
did not consider the contribution of water from Parker
and Walker Creeks due to the fact that both streams were
dry during the time that field data was collected. (RT XX
78:19-79:10.) Mr. Smith also testified that DFG did not
consider the influence of these two streams when they
developed the instream flow recommendation presented at
the hearing. (RT XX, 78:19-80:1.) The minimum instream
flow requirements for Parker and Walker Creeks, during
the summer months, will provide additional flow at the
conduit. The evidence is insufficient to determine how
much of this flow will reach Rush Creek, but the
contribution from Walker and Parker Creeks should
increase the WUA for adults in lower Rush Creek. During
October through March, the minimum instream flow
requirements for Parker and Walker Creeks of 6.0 and 4.5
cfs, respectively, will also contribute to instream flows
in lower Rush Creek.
Dr. Hardy testified that evaluation of
the total WUA for each life stage should consider the
point where the rapid increase in habitat begins to slow
down and the continued increase of streamflow provides
small increases in WUA for the particular life stage in
question. Comparison of the adult WUA indicates that 90
percent of the maximum WUA requires 47 cfs, 95 percent of
the maximum WUA requires 68 cfs and 100 percent of the
maximum WUA requires 100 cfs. Thus, in the case of Rush
Creek, it would require an additional 32 cfs in order to
provide a 5 percent increase from 95 percent to 100
percent of WUA for the adult life stage. As discussed
above, the increases in adult habitat as flows approach
100 cfs are attributable to increased habitat in the Mono
Gate One return channel, not to increased habitat in the
channel which supported the pre-diversion fishery.
In view of the issues discussed above
concerning the DFG recommendation of 100 cfs for the
months of May through September, the slow rate of
increase in the WUA for adults versus the quantity of
flow required, and the fact that the flow contribution
from Parker Creek and Walker Creek was not accounted for
in the DFG recommendation, the SWRCB concludes it would
not be appropriate to require minimum flows at Mono Gate
One corresponding to 100 percent of the WUA identified in
the Beak study. (DFG 52.) Requiring wet year minimum
instream flows at Mono Gate One which would provide 95
percent of the maximum WUA for adult brown trout in Rush
Creek will provide sufficient flow for reestablishment
and protection of the fishery.
Establishing a minimum instream flow
requirement for releases from Mono Gate One to Rush Creek
which corresponds to 95 percent of the WUA for adults
results in a 68 cfs requirement from April 1 through
September 30. Similarly, 95 percent of the WUA for
spawning can be provided at 52 cfs. In order to protect
spawning habitat, redds in the gravel and emerging fry,
the 52 cfs requirement should remain in effect from
October 1 through March 31 of wet hydrologic years. Los
Angeles' water right licenses should be amended to
require the release of these flows or the inflow to Grant
Lake, whichever is less.
Table 13 below summarizes the instream
flow requirements for Rush Creek established in this
decision for dry, normal, and wet hydrologic year types.
TABLE 13:
INSTREAM FLOW REQUIREMENTS FOR RUSH CREEK
DRY HYDROLOGIC CONDITIONS
-RUSH CREEK
|
APRIL
1 THROUGH SEPTEMBER 30
|
31
CFS1
|
OCTOBER
1 THROUGH MARCH 31
|
36
CFS1
|
NORMAL HYDROLOGIC CONDITIONS
-RUSH CREEK
|
APRIL
1 THROUGH SEPTEMBER 30
|
47
CFS2
|
OCTOBER
1 THROUGH MARCH 31
|
44
CFS2
|
WET HYDROLOGIC CONDITIONS
-RUSH CREEK
|
APRIL
1 THROUGH SEPTEMBER 30
|
68
CFS2
|
OCTOBER
1 THROUGH MARCH 31
|
52
CFS2
|
1
These instream flows will be maintained, if necessary,
with releases from storage until such time as Grant Lake
reaches a volume of 11,500 AF. If storage falls below
11,500 AF, the instream flow requirement will change to
the dry hydrologic year flow requirement or the inflow to
Grant Lake, whichever is less.
2
For normal and wet hydrologic conditions, flow
requirements are the above instream flow requirements or
the inflow to Grant Lake from Rush Creek, whichever is
less. If the inflow to Grant Lake from Rush Creek drops
below dry year instream requirements, then release from
storage at Grant Lake to maintain dry instream flows as
prescribed for dry year conditions is required until such
time as Grant Lake reaches a volume of 11,500 AF.
5.4.3 Channel Maintenance and Flushing
Flows
The DFG channel maintenance and flushing flow
recommendations for Rush Creek were developed by Dr. G.
Mathias Kondolf and presented as DFG Exhibit 168. Dr.
Kondolf's initial recommendations were modified to
conform with DFG's hydrologic classifications. The
revised DFG recommendations for channel maintenance and
flushing flows for Rush Creek are presented in Table 14
below, based on the numbers from DFG Exhibit 170A. These
flows are within the capacity of the Mono Gate One return
ditch as presented in Table 2 of SWRCB Exhibit 40.
TABLE 14:
CHANNEL MAINTENANCE & FLUSHING FLOW REQUIREMENTS RUSH
CREEK
HYDROLOGIC
CONDITION
|
REQUIREMENT
|
DRY
YEAR
|
NO
REQUIREMENT
|
DRY-NORMAL
YEAR
|
NO
REQUIREMENT
|
NORMAL
YEAR
|
200
CFS FOR 5 DAYS
|
WET-NORMAL
YEAR
|
300
CFS FOR 2 DAYS
RAMP DOWN TO 200 CFS,
MAINTAIN 200 CFS FOR 10 DAYS
|
WET
YEAR
|
300
CFS FOR 2 DAYS
RAMP DOWN TO 200 CFS,
MAINTAIN 200 CFS FOR 10 DAYS
|
RAMPING RATE - NOT TO EXCEED A
10% CHANGE IN STREAMFLOW PER 24 HOURS
|
Runoff
year definition: Dry 80-100%
exceedence (68.5% of average runoff)
Dry-Normal
60-80% exceedence (between 68.5% and 82.5% of average
runoff)
Normal
40-60% exceedence (between 82-5% and 107% of average
runoff)
Normal-Wet
20-40% exceedence (between 107% and 136.5% of average
runoff)
Wet
0-20% exceedence (greater than 136.5% of average runoff)
The ramping requirement applies to changes in flow made
by LADWP. LADWP is not required to compensate for natural
fluctuations in flow.
Dr. Kondolf indicated that the 20 percent
to 80 percent of runoff used for DFG's "normal"
hydrologic year definition was too broad for normal
hydrologic conditions. (DFG 168, pp. 10-11.) Instead, Dr.
Kondolf divided the water years into five classifications
as shown above.
Mr. Trihey testified that, based upon
composition and stability of streambed material above the
Narrows and the opportunity to rewater relic channels
below the Narrows, the channel maintenance flows of 165
cfs prescribed in the interim court order could be
increased to as much as 250 cfs. (NAS&MLC 104, p. 4
and NAS&MLC 1X, p. 11.) He further indicated that, if
flows required to maintain a higher Mono Lake level
elevation are above the minimum needed to maintain the
fishery, Rush Creek can accommodate higher flows without
substantial harm to the fishery. The best time for the
higher flows would be during the snowmelt runoff. Mr.
Trihey testified that, at 350 cfs, Rush Creek would
experience minimal erosion of streambed and streambanks.
(NAS&MLC 1X, p. 12.)
Dr. Beschta's testimony acknowledged that
ramping constraints should be developed to prevent
exceptionally rapid changes in flows. (LADWP 9, Section
2, p. 23.) As part of LADWP's revised Mono Lake
Management Plan, LADWP recognized the need for
establishing channel maintenance and flushing flows for
Lee Vining and Rush Creeks and recommended channel
maintenance and flushing flows somewhat lower than the
DFG recommendation. (LADWP 154, p. 3, Table 2.) The
channel maintenance and flushing flow recommendations
presented by DFG were supported by the detailed testimony
of an expert witness with experience in stream channel
morphology. (DFG 168, 170A; NAS&MLC 1X.)
Consequently, the SWRCB concludes that the weight of the
evidence supports adoption of the channel maintenance and
flushing flow requirement for Lower Rush Creek below
Grant Lake as recommended by DFG and identified above in
Table 14.
5.4.4 Additional Measures to Assist in
the Restoration of the Pre-Project Fishery
The long period of little or no flow in Rush Creek below
LADWP's point of diversion at Grant Lake resulted in
significant losses of riparian vegetation and other
deterioration of channel conditions. Several witnesses
presented testimony regarding pre-1941 conditions on Rush
Creek, restoration measures which have already been
undertaken under the direction of the Restoration
Technical Committee established by the Superior Court,
and recommendations for further restoration work to help
restore good fish habitat conditions.
Mr. Trihey's written testimony indicates
that low or erratic streamflows adversely affected
pre-1941 fish habitats and populations above the Narrows.
(NAS&MLC 1Y, p. 29.) The conditions that benefitted
the fishery above the Narrows were a well-developed
riparian corridor, a functioning floodplain and a stable
stream channel. The conditions that benefitted the
fishery below the Narrows were persistent streamflows,
very stable stream temperatures, abundant supply of
spawning gravel, deep low velocity water, a functioning
floodplain and a well developed riparian zone.
(NAS&MLC 1Y, p. 30.)
The focus of the restoration work which
Mr. Trihey has undertaken on behalf of the Restoration
Technical Committee was:
"...to restore the conditions
which benefitted pre-1941 fish populations such that the
pre-1941 fishery can be re-established and maintained as
required by Cal Trout II. But given the present day
institutional considerations, the existing channel
morphology and some basic relationships in physical
science it is not possible to fully restore (or even
significantly approach restoring) all of the conditions
of the Rush Creek bottomlands which benefitted the
pre-1941 fish populations." (NAS&MLC 1Y,
p. 30.)
The Restoration Planning Team conducted
research as to the conditions which benefitted the
pre-project fish populations in Rush Creek. Of the
numerous restoration measures which the planning team
prepared for consideration by the Restoration Technical
Committee, Mr. Trihey identified the specific treatments
that he considered appropriate to implement and
accelerate the recovery of a quality fish population in
Rush Creek. (RT XXVIII 33:7-33:18; NAS&MLC 105, pp.
3-9, Mr. Trihey's recommendations are identified with
asterisk.) Mr. Trihey's list of restoration
recommendations includes: the rewatering of several
historic auxiliary channels and meander bends; the
development and deepening of pools and runs; developing
spawning and rearing habitat in overflow channels; the
placement and anchoring of woody debris; developing and
enhancing backwater and wetland areas; modifying and
enforcing angling regulations to provide for the recovery
of the fishery. (NAS&MLC 105, pp. 3-11.)
Trihey and Associates prepared a
feasibility study evaluating the potential for rewatering
the historic Rush Creek below Grant Dam. Mr. Trihey's
recommendation to the Restoration Technical Committee was
that if the Restoration Committee finds it desirable to
rewater the historic channel of Rush Creek immediately
below Grant Dam, it would be most cost effective and
least complicated to implement one of the three options
proposed under design alternative "D"
(breaching the return ditch wall). (NAS&MLC 135, p.
18.) Rewatering of the historic channel below Grant Lake
was not among the restoration measures recommended by
Mr. Trihey. (NAS&MLC 105, p. 3; RT XXVIII,
33:5-33:11.)
LADWP presented testimony by Dr. Beschta
who recommended a number of interim and long-term
restoration measures for Rush Creek. The four interim
measures are: continued watering of the channel;
elimination of grazing in the riparian corridor;
placement of woody debris in channels after three to five
years; and elimination of the current program of
structurally modifying channels and adding gravel. (LADWP
9, Section 2 p. 23.) Long-term restoration measures
recommended by Dr. Beschta include: flows that mimic the
natural flow regime; flows equal to or exceeding minimum
instream flow requirements for fisheries that always be
allowed to bypass diversions; ramping constraints that
are developed to prevent exceptionally rapid changes in
flow; the occurrence of peak flows of varying timing and
magnitude that are captured in flow regimes; and, within
five to ten years, the seasonal rewatering of side
channels allowed to occur without human intervention.
(LADWP 9, Section 2 p. 23.)
In LADWP Exhibit 137, Dr. Beschta
expanded his discussion of the restoration needs for Rush
Creek. (LADWP 137, pp. 8-15.) He continued to emphasize
that the most significant restoration measure is the
return of continuous flows to Rush Creek. He recommended
that the grazing moratorium should continue until at
least the year 2000, after which the condition of the
vegetation along the stream and bottomlands should be
reevaluated. At that time, it may be possible to
reintroduce grazing as long as the grazing does not
interfere with the establishment, growth and succession
of riparian dependent vegetation. Dr. Beschta
reemphasized his opposition to structural modifications
to Rush Creek or its bottomlands and recommended that
building structures within or along the stream channel
via cabling, rebar, the placement of large rocks, or any
other means of anchoring should be prohibited. Dr.
Beschta also recommended elimination of the culvert and
road crossing at the Ford in the Rush Creek bottomlands.
Road access onto the bottomlands should be limited in
order to prevent vehicular traffic from damaging Rush
Creek.
Finally, Dr. Beschta advised that it is
not necessary to develop pool habitat for fish because
the natural process will in time develop pools which he
believes will be more stable than artifically constructed
pools. (LADWP 137, pp. 8-15.)
DFG is a member of the Restoration
Technical Committee which directed the development of
several restoration plans by Trihey and Associates.
However, DFG did not make specific recommendations
regarding restoration treatments of the stream channel or
riparian corridor for Rush Creek. Mr. Smith testified
that DFG recommends the rewatering of the historic Rush
Creek channel below Grant Lake, but did not identify
which of the rewatering options developed by Trihey and
Associates was preferred by DFG.
The evidence discussed above supports the
conclusion that, in addition to the flow requirements,
the following other measures should be undertaken to
restore and maintain in good condition the fishery as it
existed in Rush Creek prior to the diversion of water by
LADWP.
1. Minimum flows released to maintain the
fishery should remain in the stream channel and should
not be diverted for any use other than maintenance of the
Rush Creek fishery.
2. Livestock grazing should be prohibited
within the Rush Creek riparian corridor for a minimum of
ten years from the date of this order. Any resumption of
grazing in the future should be subject to approval by
the Chief of the Divsion of Water Rights of a plan
prepared by LADWP in consultation with DFG.
3. LADWP should develop a program to
place woody debris in the stream channel to provide fish
habitat in accordance with a plan developed in
consultation with the DFG.
4. LADWP should prepare a plan for
rewatering side channels and meander bends in accordance
with the procedure specified in the order at the end of
this decision. The plan should consider the following:
a. Reactivating
A-Ditch to transport excess water away from Rush Creek
during periods of high flow.
b. Providing small
seasonal surface flows in relic channels and adjacent
wetlands in the upper portion of the segment described as
study reach 2 in DFG Exhibit 52.
c. Rewatering two
meander bends below Highway 395 described in the middle
of study reach 3 (DFG 52) and also described by Trihey
and Associates. (NAS&MLC 125.)
d. Reactivating
historic channels in the segment from the Narrows to the
meadows crossing to accommodate high seasonal flows.
5. Road access in Rush Creek bottomlands
should be restricted. Vehicular traffic should be
restricted from entering or crossing Rush Creek or the
Rush Creek riparian corridor except at designated
locations.
6. Vegetation disturbed by construction
for any of the restoration activities required by this
order should be restored and revegetation should commence
as soon as construction activities have been completed.
7. LADWP should consult with DFG to
determine if additional revegetation is necessary to
maintain the fish in good condition in Rush Creek.
8. LADWP should install and maintain a
continuous recording device satisfactory to the Chief of
the Division of Water Rights to measure the flow of Rush
Creek into Grant Lake and the flow to the return ditch at
Mono Gate One.
The installation of a continuous flow
recording device and the prohibition of grazing in the
riparian corridor can be implemented without the need for
a lengthy planning period. The other measures specified
above should be addressed in the stream restoration plan
required to be prepared under the provisions of this
decision.
5.5 Summary of Measures for
Restoration and Protection of Fisheries
The
evidence establishes that restoration of continuous flows
to the four diverted streams is by far the most important
single step to restore and maintain the fishery that
existed prior to LADWP's diversions. Appropriate flow
requirements for each stream are specified in the
preceding sections. Providing channel maintenance and
flushing flows for each stream will help maintain stream
conditions that benefit the fishery and will promote the
recovery of adjacent riparian areas. The ramping rates
specified above will help to ensure that fish are not
injured by changes in flow. If future information
establishes that the flows specified for fishery
protection should be revised, the SWRCB's continuing
authority provides a means of making appropriate
revisions. The order at the end of this decision includes
a term setting forth the SWRCB's continuing authority
over LADWP's licenses.
The evidence also establishes the need
for a number of other measures to help restore and
protect fish habitat in the four streams such as
removal of livestock grazing, restriction of vehicular
access, reopening historic side-channels and other
measures specified in the findings regarding each
specific stream. These measures should be addressed in
the stream restoration plan which LADWP is required to
develop and submit in accordance with the amended terms
of its water right licenses as specified at the end of
this decision.
Finally, evidence was presented regarding
the desirability of changing fishing regulations during
the period the fishery in the four streams is recovering.
Fishing regulations are subject to the jurisdiction of
the Fish and Game Commission rather than the SWRCB. The
evidentiary record in the water right hearing, however,
would strongly support imposition of a temporary
moratorium on fishing in the stream reaches downstream of
the LADWP diversions to assist in recovery of the
fishery.
6.0 PROTECTION OF OTHER PUBLIC TRUST
RESOURCES AND BENEFICIAL USES OF WATER WITHIN THE MONO
BASIN
In
addition to the fishery resources discussed above, there
are a number of other public trust resources and
beneficial uses of water affected by water management
decisions in the Mono Basin. These include birds and
other wildlife in the Mono Basin, the organisms in Mono
Lake which provide food for birds, riparian vegetation,
air quality, visual and recreational resources, and water
quality. Sections 6.1 through 6.9 below address the
protection of these resources.
6.1 Mono Lake Aquatic Productivity
The Mono Lake alkali fly (Ephydra hians) and the
Mono Lake brine shrimp (Artemia monica) are the
major food sources of the large bird populations at Mono
Lake. The survival and reproduction of both species can
be affected by changes in salinity of the water in Mono
Lake. The salinity in Mono Lake is an inverse function of
the quantity of water in the lake; as the water elevation
rises, salinity decreases, and as the water elevation
falls, salinity increases. The majority of the evidence
presented regarding Mono Lake aquatic productivity was
incorporated into the Draft EIR for the Review of the
Mono Basin Water Rights of the City of Los Angeles and
the supporting auxiliary reports. (SWRCB 7, 13h, 13l,
13m, 13n, 13o, 13p, and 13t.) LADWP presented several
additional reports and the direct testimony of Dr. John
Melack and Dr. William Kimmerer. (LADWP 22, 24, 25,
26, 27, 28, 29, 30, 31, 32, 33, 41, 99, 100, 101, and
102.) DFG presented the direct testimony of Darrell Wong
(DFG 1), and NAS&MLC submitted the direct testimony
of Dr. David Herbst and supporting exhibits. (NAS&MLC
1G, 52, 64, 65, 66, 66A, 66B, 201, 201A, 202, 203, 218,
219, 238.)
Dr. Melack testified that he considers
that Mono Lake is "healthy" and was healthy
during the period in which he conducted his
investigations of the aquatic productivity from 1979 to
1992. (LADWP 22, Section 1, p. 22.) Lake levels during
this period ranged from a mean sea level (MSL) elevation
of 6,372 feet to 6,381 feet. Dr. Melack stated that he
could only testify to aquatic productivity conditions
that existed during his investigations and that it would
be inappropriate for him to speculate about possible
effects on aquatic productivity of conditions that may
exist at lake levels not observed during his studies. Dr.
Melack acknowledged that increased salinity levels
decreased the reproductive capability of brine shrimp
under laboratory conditions. (RT X, 48:3-48:8.)
The evidence of the effect of increased
salinity on brine shrimp is graphically displayed in
Figure 2 of Auxiliary Report No. 12. (SWRCB 13 L, Figure
2.) The graphic presentations in Figure 2 of that report
indicate that as salinity decreases to 50 grams per liter
(g/l), the various life stages of brine shrimp improve.
Auxiliary Report No. 12 concludes that "Predation
and competition are likely to be significant factors in
influencing shrimp productivity at lower salinities,
while individual physiological constraints and Atremia
interactions with nutrients and algae attain prominence
at higher salinities." (SWRCB 13 L, p. 23.)
During five years (1983-1987) of Dr.
Melack's study period, meromixis occurred. This condition
is considered a rare event, which is described as a
persistent salinity stratification which occurs when
large freshwater inputs into a saline lake cause a lens
of relatively dilute water to rest on top of a heavier
layer of more saline water. (RT X, 41:17-41:20.) The
onset of meromixis prevented the annual winter period of
vertical mixing with consequent reductions of ambient
ammonium levels in the mixed layer. This led to marked
reductions in algal biomass and annual photosynthetic
activity. (LADWP 22, Section 1, p. 15). Conclusions drawn
from the study of the interaction of brine shrimp with
ammonium and algal biomass indicate that low food levels
available during meromixis in the spring depress the
survival of brine shrimp. (LADWP 22, Section 1, p. 15.)
Laboratory experiments and direct
observations by Dr. Melack and his team of investigators
indicate that the importance of nitrogen cycling to
photosynthesis and the compensatory interaction between
algae and brine shrimp is significant within moderate
salinity ranges. The limiting factor to brine shrimp
populations may be more related to availability of food
supply than to salinity concentrations. Dr. Melack
suggests that additional investigations are needed to
develop a more precise understanding of the interactions
between nitrogen, algal and the brine shrimp components
of the pelagic ecosystem. (LADWP 22, Section 1, p. 15.)
A significant portion of the period
during which Dr. Melack conducted his investigation
occurred during the meromixis condition. Consequently,
his conclusions represent the effects of meromixis to a
large degree and, to a lesser degree, they represent the
changes to the ecosystem which occur during the more
common "monomixis" condition which exists when
the water is more evenly mixed. Dr. Melack's team
conducted an extensive monitoring program from 1982 to
1992 during which lake level and salinity changed.
Despite this extended data record, Dr. Melack concluded
that direct observation of effects of salinity on the Artemia
population is difficult and unlikely to be detected even
if present. It is likely that effects of salinity changes
experienced during the 1982-1992 study period were
obscured by effects due to meromixis. (SWRCB 13m.)
The University of California at Santa
Barbara research team headed by Dr. Melack developed
simulation models for forecasting conditions in Mono Lake
at lake levels which are outside of those observed by his
team. Two models were produced, a vertical mixing model
and a plankton model. The vertical mixing model was
designed to predict the likelihood of meromixis under
various inflow regimes. The plankton model was designed
to assess possible responses of the brine shrimp to
different lake levels. The supporting documentation
provided by the U.C. Santa Barbara team, indicated that
both of these models are quite limited. Dr. Melack's
written testimony indicates that the use of the vertical
mixing model in the Draft EIR is inaccurate due to the
possibility of missing mixing mechanisms and data
insuffi-ciencies. (LADWP 22, section 1, p. 21.) Dr.
Melack also stated that the predictive value of the
plankton model for conditions in Mono Lake possibly
occurring at lake levels not observed is uncertain.
(LADWP 22, Section 1, p. 22.) Dr. Melack acknowledged
that a rise in the lake level from 6,377 to 6,390 feet in
a monomictic condition would be a positive change.
(RT X, 119:17-119:21.)
Dr. Herbst conducted experiments on brine
shrimp growth at various salinities representing
prediversion conditions (50 g/l), present conditions (100
g/l), and at the salinity which would be present at a
lake level of approximately 6,390 feet (75 g/l). The
results of this experiment indicate that brine shrimp
hatched at all three salinities tested. However, fewer
shrimp matured to the adult stage with each increase of
salinity. Also, the shrimp that matured to adult stage
were smaller in body size with each increase of salinity.
(NAS&MLC 1g, p. 9; NAS&MLC 201, 202, and 203.)
Dr. Herbst also presented the results of
his recent experiment titled "Salinity Limits
Nitrogen Fixation in Sediments from Mono Lake,
California." (NAS&MLC 65.) The conclusion of
this experiment indicated that the increase in salinity
over the past 50 years, from 50 g/l at pre-diversion
conditions to near 100 g/l at present has been associated
with a concurrent decline in nitrogen fixation.
(NAS&MLC 65, p. 8.) Nitrogen availability is limiting
with regard to the phytoplankton algal food resource of
brine shrimp. The growth of benthic algae, an alkali fly
food source, is also nitrogen limited. (NAS&MLC 1g,
p. 11.)
NAS&MLC presented testimony by Dr.
Herbst which indicated that the Mono Lake ecosystem has
been significantly and measurably degraded as a result of
the dropping of the lake level from pre-diversion levels
to current levels. Dr. Herbst takes issue with the
statement in the Draft EIR that the cumulative impacts of
LADWP's diversions have had an unknown effect on alkali
flies. Dr. Herbst believes that any lake level
alternative below 6,390 feet has a significant adverse
effects on the alkali fly. (NAS&MLC 1G, p. 2.)
Dr. Herbst regards a lake level of 6,390 feet as the
lower limit of the range of levels for which the aquatic
productivity of Mono Lake is relatively high.
Dr. Herbst based his recommendations on
several scientific investigations he conducted himself or
as part of a team of investigators from 1982 through the
latest study completed in 1993. (RT XXIII, 245:20;
NAS&MLC 65.) Auxiliary Report No. 8 prepared by Dr.
Herbst describes experiments designed to produce field
data to assist with the evaluation of the effects of
salinity on alkali flies. (SWRCB 13h.) The experiments
"showed that productivity is significantly retarded
at higher salinities (i.e., lower lake levels).
Productivity at the current salinity of approximately 100
grams per liter ("g/l") is less than half that
at the pre-diversion salinity of approximately 50
g/l." (NAS&MLC 1G, p. 6.)
Dr. Kimmerer, representing LADWP,
testified that he and Dr. Herbst prepared the alkali
fly productivity model for use in preparing the Draft
EIR. His function was that of an expert modeler, rather
than an expert on Mono Lake or alkali flies. (RT X,
63:10-64:2.) Due to the modifications made by the EIR
consultant, Dr. Kimmerer considers the alkali fly model
used in preparing the Draft EIR to be of no value. (LADWP
41, Section 3, p. 54.)
Dr. Herbst testified that the primary
difference between the model which he and Dr. Kimmerer
prepared and the modified model used in the Draft EIR is
that the modified model relies on assumptions about birth
and death rates which are arbitrary. The model developed
by Dr. Herbst and Dr. Kimmerer was based upon empirical
data obtained from field and laboratory studies.
(NAS&MLC 1g, p. 7.) Although the two versions of the
model produce similar results, Dr. Herbst indicated that
the original version is more reliable. Both models
indicate that increasing salinity has a pronounced effect
upon alkali flies. (NAS&MLC 1g, p. 7.)
In summary, LADWP presented expert
testimony that the Mono Lake ecosystem at lake levels of
6,372 to 6,381 feet is in a "healthy"
condition. The testimony of LADWP's experts also
indicates that increased salinity has caused decreased
productivity of brine shrimp under laboratory conditions.
Expert testimony presented by NAS&MLC indicates
that increased salinity and other effects of lower lake
levels had adverse effects upon both the alkali flies and
the brine shrimp.
Based on the evidence presented, the
SWRCB concludes that a water level in Mono Lake at or
near 6,390 feet will maintain the aquatic productivity of
the lake in good condition. Lake levels below 6,390 feet
will have some negative effects to Mono Lake aquatic
productivity although the extent of the adverse effect is
difficult to quantify.
6.2 Hydrology, Riparian Vegetation and
Meadow/Wetland Habitat
An extensive body of information has been compiled
describing the pre-1941 and post-1941 hydrologic and
vegetative conditions in the Mono Basin. Much of the
information was presented in the Draft EIR and auxuliary
reports, and additional information was presented at the
evidentiary hearing. (e.g., SWRCB 3, 4, 7, 10 and 13a:
NAS&MLC 116, 122, 125, 127, 137 and 175; and CT 5D,
5K, 5O, 5R and 15; and LADWP 7.)
6.2.1 Pre-1941 Hydrologic Conditions
Mono Basin streams have a long history of water
diversions dating back to the 1860s. Water was diverted
from Mono Basin streams for irrigation, milling, mining,
hydroelectric power generation, stockwatering and
domestic use. Irrigation water was diverted and moved
from many of the basin's streams by a system of ditches
and canals. Most diversions were during the irrigation
season, although some continued throughout the year.
(SWRCB 7, Vol. 1, 3C27-28.)
Diversion of Walker and Parker Creeks for
irrigation began in the 1860s on the present day Cain
Ranch and, by 1930, most of the flow was diverted for
irrigation. (SWRCB 7, p. 3C-4.) The annual average runoff
from Walker Creek is estimated at 5,400 acre-feet. The
annual average runoff of Parker Creek is estimated at
9,100 acre-feet. (SWRCB 7, Vol. 1, p. 3A6-7). In the
years immediately preceding LADWP's export of water from
the Mono Basin, irrigation diversions from Walker Creek
were approximately 4,000 acre-feet per year and
irrigation diversions from Parker Creek were
approximately 5,900 acre-feet per year. (LADWP 6, p.
130.)
Prior to 1915, no water storage existed
on either Rush or Lee Vining Creeks. Dams were
constructed at Gem Lake and Agnew Lake as part of a Rush
Creek power project which began operation in 1916. (LADWP
7, Appendix I, p. VII.) A power project on Lee Vining
Creek began operation on October 5, 1924. (LADWP 7,
Appendix I, p. IX.) In 1915, a 10 foot high dam was
constructed on Rush Creek to enlarge the capacity of
Grant Lake. The height of the dam was increased to 20
feet in 1925 to provide additional storage for
irrigation. (NAS&MLC 125, p. 3.)
During the 1920s and 1930s, the
historical period of maximum irrigation, an average of 50
percent of the annual flow of Rush Creek was diverted
into three major irrigation ditches between Grant Lake
Dam and the old Highway 395 bridge. The A-Ditch and
B-Ditch diversions caused local dewatering of Rush Creek
between B-Ditch and the Parker Creek confluence. These
diversions were used to apply large quantities of water
(up to 45 acre-feet/acre) on the highly permeable
substrates of Pumice Valley. (SWRCB 13a pp. 21-22.)
Indian Ditch diverged approximately 2,000 feet downstream
of the Rush Creek narrows and flowed parallel to the
western side of Rush Creek to an area colloquially called
the "lower meadowlands." Irrigation from Indian
Ditch ceased shortly after 1940.
Lee Vining Creek water was diverted by
six main irrigation canals and several minor diversions.
O-Ditch which conveys irrigation water to streamside
meadows above the USFS Ranger District compound is still
in use. Lee Vining Ditch (aka Curry Ditch) diverged
immediately above U.S. Highway 395 and was used until
1959 as a water supply for the town of Lee Vining and for
irrigation of nearby land. The Ney and Jamison ditches
diverted water from Lee Vining Creek below U.S. 395 to
irrigate pastures on the west and east sides of the creek
near the county road. Other ditches also diverted water
for in-basin irrigation, but most were abandoned by the
early 1950s. (SWRCB 13a, pp. 23-24 and SWRCB 7, Vol. 1,
p. 3C-5.)
Pre-1941 agricultural and power
diversions influenced local hydrologic and biotic
conditions particularly on Rush Creek. During the early
decades of this century, large quantities of water were
diverted from Lee Vining, Walker, Parker, and Rush Creeks
and applied to surrounding land. Combined diversions
ranged from 46,000 acre-feet per year to 81,000 acre-feet
per year with an average of 60,000 acre-feet per year for
the period 1925 to 1929. (LADWP 6, p. 133.) Much of that
water (less evapotranspiration) probably returned to the
basin in shallow ground water tables that sometimes
formed springs along the creeks or entered Mono Lake as
unmeasured ground water inflow.
The history of diversions is an important
factor in understanding the pre-1941 riparian communities
because: (1) diversion of water dewatered some stream
sections, at times leaving no surface flow; (2)
irrigation diversions appear to have contributed
substantially to springflow along the Rush Creek
bottomlands and elsewhere, significantly augmenting the
base flow of the stream while also supporting wetland and
riparian communities (SWRCB 13a, p. 20; NAS&MLC 116,
p. 13; and NAS&MLC 122, p. 5); and (3) upstream
regulation by hydroelectric power projects increased the
streamflows during the late summer and fall irrigation
season. (LADWP 7, p. 5.)
In addition, grazing probably had an
important impact on riparian vegetation. Twelve hundred
to eighteen hundred head of cattle grazed the Cain
Irrigation Company lands annually in the late 1920s from
April to October. (LADWP 7, p. 9.) Dr. Platts testified
that heavy grazing occurred along Rush Creek up to 1941.
(LADWP 1, p. 2.) Grazing in the Mono Basin in general was
heavy in 1940. On April 1, 1940, for example, 9,100
cattle, 825 horses and 25,000 sheep were grazed in the
Mono Basin. (LADWP 1, p. 3.) Dr. Beschta testified that
by 1940 extensive grazing had probably caused significant
changes to plants along the streams in the Mono Basin,
but the overstory canopies remained largely intact.
Channel banks were impacted by grazing, but widespread
channel changes had not yet occurred. (LADWP 9, p. 21.)
Photographs by Elden Vestal show indicators of localized
bank and vegetative impacts probably due to livestock
grazing. (CT 5M and 5O.) The high flow event of 1938 did
not significantly alter stream channels, however, because
riparian vegetation was sufficiently intact to resist
erosive forces. (LADWP 9, p. 22.) Thus, the record
shows that, prior to 1941, the long-term impact of
grazing was localized and the riparian community was
still intact and helped protect stream channels from
erosion.
6.2.2 Post-1941 Hydrologic Conditions
LADWP constructed the
present-day Grant Lake Dam in 1939 and 1940, thereby
enlarging the existing Grant Lake to provide a maximum
storage capacity of about 48,000 acre-feet. LADWP
constructed diversion facilities on Lee Vining Creek,
Walker Creek, and Parker Creeks so that flows could be
diverted to Grant Lake through the Lee Vining Creek
Conduit. The Lee Vining Creek Conduit has a capacity of
approximately 300 cfs at Lee Vining Creek, 325 cfs at
Walker Creek and 350 cfs at Parker Creek. (NAS&MLC
125, p. 3; SWRCB 7, pp. 3A-14 and 15.) The 11 mile long
Mono Craters Tunnel was constructed to convey water from
the Mono Basin into the upper Owens River. In 1940, LADWP
constructed Long Valley Dam to hold the Mono Basin
exports in Crowley Reservoir. (SWRCB 7, Vol. 1, 3A-16.)
LADWP began diversions from the Mono
Basin in April of 1941. Between April 1941 and March
1970, annual out-of-basin diversions averaged
approximately 57,000 acre-feet per year. (NAS&MLC
125, p. 3.) In 1970, the LADWP Aqueduct facilities were
enlarged with construction of the "second
barrel" between Haiwee Reservoir and Los Angeles.
The original aqueduct had a capacity of 500 cfs and an
annual export capacity from all sources in the Owens
Basin and the Mono Basin of about 360,000 acre-feet per
year. With the addition of the second barrel, the
aqueduct gained an additional 300 cfs capacity,
increasing annual exports from the Owens and Mono Basins
to about 585,000 acre-feet per year. (SWRCB 7,
Vol. 1, p. 3A-17.) Annual Mono Basin exports
increased to an average of 102,000 acre-feet per year
through 1981 which represents 82 percent of the long-term
average runoff from Rush Creek and Lee Vining Creek.
(NAS&MLC 125-p. 3.) Between the late 1940s and
mid-1980s, water exports resulted in the dewatering of
the lower reaches of the four Mono Basin streams diverted
by LADWP.
6.2.3 Riparian Vegetation and
Meadow/Wetland Habitats
Riparian areas provide many ecological benefits including
habitat for a diversity of wildlife, flood flow
attenuation and bank stabilization, invertebrate food
production for fish and wildlife, nutrients for aquatic
systems, and recreational opportunities such as hiking,
fishing, wildlife observation, camping and photography.
(SWRCB 7, Vol. 2. p. 3C-7; SWRCB 7 Vol. 2; p.
3J-11.)
Riparian vegetation in the Mono Basin
consists of trees and shrubs that occur on tributary
floodplains, banks, springs or seeps. Meadow/wetland
habitats are grasslands with waterlogged soils near the
surface but without standing water for most of the year.
(CT 15, p. 6-1.) Historically, riparian conifer forests
dominated streamsides in the higher elevations and gave
way to conifer-broadleaf forest and cottonwood-willow
woodlands at successively lower elevations creating a
generally continuous corridor from the montane forests of
higher elevations to near the lakeshore of Mono Lake.
(SWRCB 7, Vol. 1, p. 3F-10.) High ground water,
irrigation, springs and the seasonal overbank flow
provided the necessary water to support meadow/wetland
habitats.
Prior to LADWP diversions, Lee Vining
Creek had approximately 32 acres of seasonally wet
meadow. This meadow was located west of Lee Vining Creek
near the stream mouth above and below the county road and
was irrigated by an unnamed ditch. Maintenance of the
meadow was believed to be dependent on irrigation. It has
since reverted to sagebrush. (SWRCB 13a, p. 59.)
Historically, wetland/meadow habitat on
Rush Creek occurred on the floodplain, at hillside seeps
or springs and in irrigated areas. Rush Creek had
approximately 131 to 133 acres of meadow or wetland
habitat along the creek. This does not include
approximately 130 acres of lake fringing wetlands located
on the Rush Creek delta. (SWRCB 7, Vol. 1, Table 3C-14;
CT 15, pp. 6-12 and 6-13; and CT 5M, photograph of Rush
Creek delta.) Most of the streamside habitat was located
in the bottomlands.
6.2.4 Effects of LADWP Water Exports
on Riparian Vegetation
Between
1941 and the 1960s, much of the riparian area along lower
Rush, Parker, Walker and Lee Vining Creeks was desiccated
due to the lack of flow in the diverted stream reaches. A
fire in lower Lee Vining Canyon in the early 1950s
destroyed much of that desiccated riparian community.
Additionally, the reduction or cessation of irrigation
from the "A" and "B" ditches impacted
the Rush Creek bottomland springs, meadows and associated
riparian community.
The diversion of water from the Mono
Basin caused the water level in Mono Lake to drop 45
vertical feet to 6,372 feet at the historic low water
level. The water level was approximately 6,375 feet in
the winter of 1994. Due to the lowering of the lake and
the deterioration of riparian vegetation, flood events in
the late 1960s and early 1980s resulted in major incision
of tributary deltas and streams. Incision into former
floodplains drained shallow ground water tables and left
former side channels stranded above the newly incised
main stream channels. The high flows caused extensive
erosion resulting in a shifting, widening and
straightening of the primary stream channels due in part
to the lack of stabilizing riparian vegetation. (SWRCB
13a, pp. 50-53 and pp. 61-64; CT 15, p. 2-1; and
NAS&MLC 125 p. 3.) Reduced flows and widening of the
channels eliminated overbank flooding which, in turn,
reduced the vigor of riparian vegetation and wetlands.
The loss of the riparian community had serious impacts on
the fishery of Rush and Lee Vining Creeks. (CT 15, p.
5-3.)
The Draft EIR compares the pre-diversion
riparian vegetation acreage on the four diverted
tributary streams with the 1989 point of reference
conditions. (SWRCB 7, Vol. 1, Chapter 3C, Table 3C-2.) A
reach-by-reach description of the vegetation is found in
Appendix P of the Draft EIR. (SWRCB 7, Appendix P,
p. 11-21.) Based on the data in the Draft EIR, a
total of 204.4 acres of mature woody riparian vegetation
had been lost on the four streams by 1989. Losses of over
100 acres of meadow and wetland acreage had also
occurred. The largest losses of riparian vegetation and
meadows were in the Rush Creek bottomlands and lower Lee
Vining Creek below U.S. Highway 395. Most of the riparian
vegetation losses were directly due to the export of
water from the Mono Basin.
During the period from 1941 to the 1980s,
LADWP leased out grazing rights to its land in the area
of all four diverted streams. There has been a
significant decrease in the acreage of meadow habitat on
Rush Creek compared to pre-1941 conditions. In 1989,
approximately 40 acres of the streamside meadow or
wetland habitat remained of the previous approximately
130 acres. (SWRCB 7, Vol. 1, Chapter 3C, Table
3C-14.) This loss of meadow and wetland area is believed
to be due to the reduction or elimination of irrigation
diversions, diversion of water from Parker and Walker
Creeks, the incision of Rush Creek and the lack of
overbank flooding. (CT 15, pp. 6-13 to 6-15.) Continued
grazing on the desiccated meadows has probably
contributed to deterioration of the meadow and wetland
habitats. (SWRCB 7, Vol. 1 p. 3C-81.)
6.2.5 Stream Restoration Work and
Riparian Vegetation
As discussed in Sections 5.0 through 5.5, considerable
stream restoration work has already been done at the
direction of El Dorado County Superior Court, but
there are additional measures that should be taken to
help restore the fisheries in the four diverted streams.
LADWP presented two videotapes to
document the natural recovery of riparian vegetation on
Lee Vining Creek and Rush Creek between the
"Narrows" and the "Ford." (LADWP 11
and 139.) The videotapes document prolific growth of
vegetation in the stream reaches depicted, but testimony
from Mr. Messick, who participated on the Restoration
Technical Committee planning team, indicates that
vegetation recovery has been highly variable and not
continuous along the streams. The recovery is primarily
along the edges of the existing main channels and those
side channels which now carry water. Mr. Messick
testified that there is little natural recovery on the
floodplain area between the stream channels. Mr. Messick
also testified that there is very little natural recovery
in some sites just a few feet away from the stream. (RT
XL, 16:3-16:18.)
Dr. Stine testified that much of the
vegetation, depicted in LADWP Exhibit 139 as recently
established, actually had been there longer than ten
years. (RT XL, 90:1-90:17.) Some scenes from the
videotape looking upstream on Lee Vining Creek from the
county road depict a cobble floodplain with sparse
riparian vegetation recovery. (LADWP 11.) Mr. Messick
testified that cobble sites such as depicted in the
videotape will take more than 20 to 40 years for natural
recovery and that these sites are extensive on Lee Vining
Creek. (RT XL, 55:14-15:22.) There are also similar sites
on Rush Creek. Mr. Messick identified several reasons for
the lack of uniform recovery:
(a) overbank flows that favor
establishment of riparian species had not occurred in
these areas since the streams were rewatered;
(b) the channels have been incised resulting in a lower
water table which reduces the chances of establishing
seedlings; and
(c) loss of topsoil, leaving the remaining surface which
is composed of large gravel and cobbles and which is
relatively hot and dry. (RT XL, 16:19-16:25 and
17:1-17:14.)
Mr. Messick believes that sites with
shallow water tables are the sites to be considered for
active restoration as opposed to those areas already
experiencing rapid natural recovery. (RT XL, 56:1-56:21.)
Mr. Messick believes that active intervention by planting
riparian vegetation is feasible and would be very
beneficial for Rush, Lee Vining, Walker and Parker
Creeks. (RT XL, 43:13-43:24 and 45:1-45:19.)
Dr. Stine testified that Rush Creek will
not reoccupy the abandoned channels without active
intervention. He believes that by removing the cobble
plugs in the now existing multiple abandoned channels and
rewatering those channels, Rush Creek could very rapidly
return to the multi-channeled system that existed
previously. (RT XL, 102:1-102:21.) At the time of the
hearing, the Restoration Technical Committee Planning
Team was preparing a report on the feasibility of
rewatering channels on Rush Creek. (RT XL, 121:8-122:3.)
Dr. Stine believes that reoccupying former channels on
Lee Vining Creek would be easier than on Rush Creek
because of a somewhat different geomorphology. (RT XL,
103:13-103:22.) Dr. Stine also supports planting riparian
vegetation to accelerate recovery on sites along Rush and
Lee Vining Creeks. (RT XL, 104:1-105:12.)
6.2.6 Conclusions Regarding Riparian
Vegetation
Based on the
evidence discussed in Sections 5.1 through 6.2.5 above,
we conclude that riparian and meadow areas in the Mono
Basin were affected by pre-1941 land and water management
practices in various ways. Grazing practices had adverse
effects on riparian vegetation in some areas, but
long-term impacts from grazing were localized and the
riparian community remained intact and much more
extensive than today. On the positive side, water
diversions for irrigation in the pre-1941 period
contributed to springflows in the Rush Creek bottomlands
and provided water for vegetation in riparian and meadow
areas.
There is widespread recognition that the
changes in water management practices since 1941 due to
Mono Basin water exports have had major adverse impacts
on riparian areas. Some of those effects are
irreversible; some could be mitigated by a return to the
irrigation and water management practices that prevailed
before 1941; some will be mitigated by the return of
continuous flows and channel maintenance flows as
discussed in preceding sections; and others could be
mitigated by various other restoration measures.
No party to this proceeding has urged a
general resumption of the water management practices
which prevailed in the years preceding 1941, practices
which at times resulted in diverting the entire
streamflow for irrigation. Rather than resuming
large-scale irrigation within the Mono Basin, most
parties to this proceeding recommend providing continuous
instream flows for fishery protection and requiring most
of the available water to flow to Mono Lake in order to
raise the lake level. Thus, it is not realistic to expect
full restoration of pre-1941 meadow and riparian areas,
some of which were dependent upon water diversion for
irrigation.
As discussed in preceding sections of
this decision, however, there are a number of reasonable
measures which can be taken to help promote the recovery
of Rush Creek, Lee Vining Creek, Parker Creek and Walker
Creek. Measures such as maintenance of continuous
instream flows, providing periodic channel maintenance
flows, continued exclusion of grazing, reopening side
channels, and restricting vehicular access to stream
channels and flood plains will not only directly benefit
recovery of fisheries, but will also promote recovery of
riparian vegetation. As discussed in Section 5.5, this
decision requires that LADWP prepare and submit a plan to
address specified stream restoration measures. The SWRCB
recognizes that considerable work already has been
undertaken by the Restoration Technical Committee under
the direction of the El Dorado County Superior Court. In
addition to the measures specifically identified in
Section 5.5 above and completion of work done at the
direction of the Superior Court, the SWRCB believes that
the stream restoration plan which LADWP submits to comply
with this order must consider other potential measures
identified in the Draft EIR to help restore riparian
areas along the four streams.
6.3 Wildlife and Wildlife Habitat
The Draft EIR reports that historical observers recalled
the Rush Creek bottomlands once supported abundant
waterfowl, deer, mountain lions, bobcats, and coyotes.
(SWRCB 7, Vol. 2, p. 3F-11.) Nearly 300 bird species have
been identified at Mono Lake including 98 species of
water birds. (SWRCB 7, Vol. 2, p. 3I-9.) Dr. Joseph
Jehl Jr. testified that prior to diversions by LADWP,
there were no Caspian Terns in the Mono Basin and the
population of gulls was small. Dr. Jehl testified that
phalaropes and grebes were present, but the population
numbers are not known. Dr. Jehl believes that snowy
plovers were present but knows of no confirming evidence.
(RT XII, 125:20-126:9.) The numbers of ducks and geese in
the Mono Basin were much greater than today. (See Section
6.3.7 below.)
In 1991, Jones and Stokes Associates
conducted surveys to characterize the wildlife species
inhabiting streamside, lakeshore, upland and island
habitats in the Mono Basin and floodplain habitats on the
upper Owens River. (SWRCB 7, Appendix D.) A complete
list of the species observed during the survey is found
in Table D-4 of Appendix D of the Draft EIR. GMore
detailed information concerning Mono Basin wildlife is
provided in four Auxiliary Reports prepared for the Draft
EIR.
The sections which follow discuss
wildlife habitat conditions prior to 1941, wildlife
habitat conditions following many years of Mono Basin
water exports, and several species of particular interest
which were addressed at the hearing.
6.3.1 Pre-1941 Land-Use and Wildlife
Habitat Conditions
As discussed in Section 6.2.1, large quantities of water
were diverted from Mono Basin streams for in-basin
irrigation prior to 1941. A report from 1880 indicated
that more than 2,000 acres of sagebrush near Mono Lake
had been converted to tillable farmland at that time.
Farms were concentrated along Mill, Lee Vining, Walker,
Parker and Rush Creeks. Pasture areas were created by
expanding and irrigating natural meadows. (SWRCB 7, Vol.
2, p. 3G2-3.) In addition to agricultural land use,
vacation homes and resorts were developed along the
streams and near lakes at higher elevations.
Despite the agricultural development and
other land-use changes that had occurred prior to 1941,
the Mono Basin still sustained important wildlife
habitats and wildlife populations. In preparing the Draft
EIR, the consultant reviewed published literature and
field notes of expert naturalists and interviewed
long-time Mono Basin residents about their recollections
of wildlife resources prior to 1940. Although few
quantitative data are available that describe the
prediversion wildlife resources of the Mono Basin (SWRCB
7, Vol. 2, p. 3F-2.), it is undisputed that Mono Lake
represents a major stopover point for migratory water
birds in western North America. The lake also is an
important nesting area for several species of birds. The
wildlife habitats described below have been most
influenced by the export of water from the Mono Basin.
Lake-Fringing Wetlands: Prior to
Mono Basin water exports, Mono Lake supported varied
lake-fringing wetlands formed from springs and seeps
along its margins as well as unvegetated brackish
shoreline lagoons. (SWRCB 7, Vol. 1, p. 3C-11.) An
extensive discussion of the historic and modern
distribution of lake-fringing wetlands and their
geohydrology is contained in SWRCB Exhibits 7 (Appendix
Q), 13aa, and 13u.
The EIR consultant delineated eighteen
lake-fringing wetland areas at Mono Lake including Paoha
Island. (SWRCB 7, Vol. 1, Table 3C-3.) These wetland
areas include marshes, wet meadows, dry meadows, alkali
meadows and lagoons. A more complete description of the
lake-fringing vegetation classification system used in
the Draft EIR is included in SWRCB Exhibit 7, Appendix F.
A majority of the wetlands were natural, though some were
the result of human modifications including irrigation,
excavation, or impoundment such as the artificial duck
ponds on the Rush Creek delta. (SWRCB 13u, pp. 4 and 21.)
Lake-fringing wetlands serve a number of
functions including providing wildlife habitat. Prior to
1941, there were 617 acres of lake-fringing wetlands
which included 260 acres of brackish lagoons, 175 acres
of dune lagoons, 38 acres on the Rush Creek delta, 29
acres at Bridgeport Beach, 4 acres at Black Point,
3 acres at the Wilson and Mill Creek deltas and 6
acres at DeChambeau Marsh. (SWRCB 7, Appendix D, p. 26.)
In addition, there were 356 acres of marsh, wet meadow,
and wetland willow scrub. (SWRCB 7, Vol. 1, Table 3C-4.)
Mono Lake Islands and Islets: Mono
Lake has two major islands, Negit and Paoha. While both
are of relatively recent volcanic origin, there are
differences in composition which have biological and lake
management implications. Both islands and their islets
are potential nesting areas for California gulls and
terns.
Negit Island is a 1,700 year old
composite volcano composed of two domes, a rocky cinder
cone and several lava flows. Part of the island is
covered with sandy and silty volcanic ash from the nearby
Mono Craters. These areas have been colonized by a
greasewood shrub layer. There are no freshwater sources
on the island. At a lake elevation of 6,417 feet, Negit
Island is flanked by smaller volcanic islets (Krakatoa,
Little Norway, Twain, Steamboat and Java) locally covered
with sand deposits ranging in size from .223 acres to
approximately .010 acres. (SWRCB 13u, Appendix.) The rock
composition of the islets and Negit Island resists
erosion by waves. (SWRCB 13v, pp. 2-3.) However, the
number and size of the islets depends upon the water
level of Mono Lake. In 1940, Negit Island consisted of
about 162 acres separated from the mainland by 2.5 miles
of open water. (SWRCB 7, Vol. 2, p. 3F-3.)
Paoha Island is a large mass of compacted
lakebed sediments (mudstones) that were uplifted in a
volcanic event approximately 330 years ago. Paoha Island
was approximately 1,236 acres in size in 1940. (SWRCB 7,
Vol. 2, p. 3F-3.) The mudstones are far less durable than
the volcanic material that makes up Negit Island and its
islets. (SWRCB 13t, p. 21.) Great Basin scrub habitat,
dominated by greasewood and sage, is the most abundant
habitat type on Paoha Island. This habitat type provides
nesting, escape, and resting cover, as well as foraging
habitat for some species. Freshwater springs near the
southeast side support emergent marshes and alkali
meadows. These springs are an important source of
freshwater for most species of terrestrial wildlife on
the island. (SWRCB 7, Appendix D, pp. 27-28.) Two saline
lakes are located on the northeast end of the island. The
recently emerged Paoha islets are composed of the same
unconsolidated lakebed sediments originating from a slide
from the flank of Paoha Island. The Paoha islets were
submerged until 1961 when the water level of Mono Lake
fell below 6395 feet. (SWRCB 13v, Appendix.)
Waters of Mono Lake: Eared Grebes,
red-necked phalaropes, Wilson's phalaropes, and many
species of shorebirds and waterfowl use Mono Lake in the
summer and fall for a feeding and resting area before
continuing their annual migration. At prediversion
elevations, Mono Lake had a salinity of approximately 48
grams/liter. (SWRCB 7, Vol. 1, Figure 3B-1.) Near the
mouths of the tributary streams, a phenomena called
"hypopycnal stratification" occurs in which the
lighter fresh water flowing into the lake floats on the
top of the denser saline water already in the lake. (RT
XXI, 15:4-15:20; NAS&MLC 178, photo.) This fresh
water lens may persist for some time before it becomes
mixed by wind-induced waves with the saline water of the
lake. (RT XXI, 17:12-17:25.) In many cases, the
hypopycnal lenses of fresh water were adjacent to
marshes. This important association tended to concentrate
waterfowl in marsh areas as depicted in the Dombrowski
map of Mono Lake prepared in the late 1940s. (NAS&MLC
176.) Waterfowl could sit in this fresh water lens and
drink, rinse salts from their feathers, and be protected
from predators, while freely moving back and forth to the
adjacent wetlands. Waterfowl were hunted in these areas
prior to Mono Basin water exports. (RT XXI, 44:8-44:18.)
Tributary Wildlife Habitats: The
streams feeding Mono Lake originate high in the eastern
slope of the Sierra Nevada. By the prediversion period,
the riparian vegetation along these streams had developed
into nearly continuous corridors stretching from Mono
Lake to the upper watersheds. Wetlands and meadows at
various places along the tributary streams were important
wildlife habitats. Below the LADWP points of diversion,
the four diverted tributaries supported a combined total
of approximately 492 acres of mature woody riparian
vegetation and 175 acres of meadow and wetland
vegetation. (SWRCB 7, Vol. 1, Table 3C-2.) These areas
were used by wildlife for nesting, foraging, resting, and
as migratory corridors.
6.3.2 Post-1941 Wildlife Habitats
In the post-1941 period, there have been extended periods
in which the four streams diverted by LADWP had little or
no flow below the LADWP points of diversion. Relicted
lakeshore habitats have changed in character, acreage,
and quality. Island and islet habitats have experienced
similar changes. The Draft EIR reports the net changes in
acres for particular types of habitat between pre-1941
conditions and conditions examined as part of a 1991
wildlife habitat analysis. (SWRCB 7, Appendix D, Table
D-5.) A summary of the changes in various types of
habitat is provided below.
Changes in Lake Fringing Wetlands:
By 1989, LADWP stream diversions and the lowering of Mono
Lake resulted in the reliction of approximately 14,560
acres of former lakebed. Nearly 6,000 acres of the
relicted lakebed (playa) exists as unvegetated alkali
flats of very low wildlife value. However, the playa is
potential habitat for the snowy plover, a candidate
species for listing as threatened or endangered under the
federal Endangered Species Act. Snowy plovers are
discussed in Section 6.3.6. Current lakeshore areas are
dominated by alkali flats, dry and alkali meadows, and
tall and short emergent marshes. (SWRCB 7, Vol. 2, p.
3F-32.)
Alkali and dry meadows currently occupy
nearly 4,000 acres of Mono Lake shoreline. This
represents a significant increase over prediversion
acreages. These habitats provide some cover and foraging
opportunities, but have little general wildlife value and
use. (SWRCB 7, Vol. 2, p. 3F-33; RT VI, 134:10-134:13.)
DFG Biologist Ron Thomas testified that the habitat
quality of these "new" wetlands is very much
diminished from what used to exist. (RT XXI, p.
53:2-53:11.) The lake fringing wetlands existing today
lack freshwater and brackish water open-ponded areas. (RT
VI, 208:5-208:24.) The existing alkali flats and alkali
meadow have very little habitat value for migratory
waterfowl. (RT VI, 135:3-135:22.)
Wet meadows (brackish and freshwater)
currently occupy about 50 acres around the existing
shoreline. These habitats receive limited wildlife use
due to their limited extent and lack of open water. The
habitat value and use of almost 1,000 acres of emergent
marsh by marsh-nesting birds is reduced by the lack of
open water. (SWRCB 7, Vol. 2, p. 3F-33.) The present
marshlands are no longer adjacent to the lake and are not
associated with the near-shore hypopycnal phenomena
discussed above. (RT XXI, 29:10-29:15.) Instead of
freshwater traveling a short distance before flowing into
Mono Lake as a concentrated stream, the freshwater now
diffuses over a large area of the shore and flows into
Mono Lake in many areas. (RT XXI, 28:11-28:23.)
When the lake level dropped below the
tributaries' delta plains, stream incision caused the
draining of the delta lagoons which were important
open-water habitats. These small ephemeral lagoons were
created by berms of stream cobbles, gravels and sands
deposited by the streams and shaped by shoreline currents
and waves. The delta lagoons were lost when lake
elevations dropped below 6,400 feet. (SWRCB 13u, pp.
20-21.) At lake levels less than 6,400 feet, the steeper
gradient of the shoreline limits the formation of lagoon
features to areas around the mouth of the streams.
Lagoons are relatively rare elsewhere along the lake
shore. (SWRCB 13u, pp. 15-16.)
Large persistent lakeshore lagoons were
an historic feature of the northern shore of Mono Lake.
Lakeshore lagoons cease ponding water when the lake
elevation drops below 6,400 to 6,412 feet, depending on
the lagoon floor elevation. (SWRCB 13u, pp. 17-20). The
large shoreline lagoons are depicted in a photomosaic of
Mono Lake from 1929 or 1930. (NAS&MLC 159.) These
brackish lagoons are present until the lake drops below
6,400 feet. (RT XXI, 18:2-18:17.) Changes in Mono
Lake Islands and Islets: The
decrease in the water level of Mono Lake has resulted in
several important changes in island area and
configuration, some of which have biological
implications. Negit and Paoha Islands have increased in
size with the fall of Mono Lake. Negit Island increased
from approximately 162 acres in 1940 to 263 acres when
the water level of Mono Lake reached its historical low
of 6,372 feet in October 1982. Paoha Island increased
from approximately 1,236 acres in 1940 to 2,130 acres in
October 1982. The lower lake levels also increased the
size of the pre-existing Negit islets and caused new
islets to emerge. The Paoha islets did not emerge until
the water level declined to approximately 6,395 feet in
1961. (SWRCB 13v, Appendix.)
At a lake elevation of 6,375 feet, Negit
Island becomes connected to the mainland by a land
bridge. (SWRCB 13v, p. 6.) The landbridge begins as an
island that emerges from the strait between Negit Island
and the lake shore at approximately 6,390 feet.
(NAS&MLC 198.) As the lake level falls, the island
grows to form the land bridge at 6,375 feet. (RT XXIII,
135:13-136:13; NAS&MLC 21 and 142A, photographs of
land bridge.) The land bridge provides access for coyotes
and other terrestrial predators to California gulls
nesting on Negit Island.
A rise in the future lake level would
affect the Paoha islets. Unlike the hard rock of the
Negit Archipelago, the mudstone of the Paoha islets is
easily eroded by waves and longshore currents. Auxiliary
Report 22 to the Draft EIR describes a recent example of
how the islets were modified by changes in lake level.
(SWRCB 13v, pp. 13-15.) When Mono Lake fell to 6,381 feet
in 1974, there were 12 Paoha islets with a total area of
24 acres. The lake continued to fall reaching its
historic low level of 6,372 feet in 1982. By August 1986,
the water level rose to 6,380.9 feet, but erosion caused
by the rising lake reduced the number of islets by half
with a combined area of 11 acres.
Changes in Mono Lake Habitats: The
reduction in lake elevation has reduced the surface area
of Mono Lake by over 25 percent and caused lake water
salinity to increase by approximately 100 percent. The
open and near shore waters of Mono Lake are used as
feeding zones for several species of birds such as gulls,
eared grebes, red-necked phalaropes, Wilson's phalaropes
and several species of waterfowl. Habitat quantity and
quality are critical to the algae, alkali flies and brine
shrimp that form the foodweb that supports overall
productivity of the Mono Lake ecosystem. The relationship
between salinity and the aquatic productivity of Mono
Lake is addressed in Section 6.1. The loss of the linkage
of hypopycnal lenses (i.e., fresh water overlying saline
lake waters) with fresh water marshes and lagoons has
resulted in reduced wildlife habitat, particularly for
waterfowl. (NAS&MLC 180, 181, and 182, photographs.)
Tributary Habitats: As discussed
in Section 6.2.4, the diversion of the tributary streams
and the fall of Mono Lake resulted in stream incision,
erosion, and other geomorphic changes. (NAS&MLC 1W,
pp. 6-9.) The direct impacts to terrestrial wildlife
habitats were the loss of complex multi-storied riparian
forest, fragmentation of the riparian corridors, and
draining of wetlands, overflow channels, delta marshes,
ponds and lagoons. (NAS&MLC 1U, pp. 5-7.) The result
has been a reduction in habitat diversity and complexity,
and an increase in lower valued wildlife habitats such as
willow scrub, unvegetated floodplain, and Great Basin
scrub.
6.3.3 California Gulls
California gulls (Larus californicus)
typically nest in open areas on islands, if possible next
to some kind of object such as a rock, log or shrub. (RT
XII, 81:7-81:9). The Mono Lake colony is the second
largest concentration of California gulls in the world.
The Great Salt Lake in Utah is the largest. DFG has
listed the California gull as a species of special
concern. (RT XXIII, 145:13-145:22.)
The current California gull population at
Mono Lake is between 60,000 and 65,000 breeding adults.
(RT XXIII, 145:23-145:24.) The next largest colony in the
state is located at Clear Lake in Modoc County with a
population between 5,000 and 10,000 adults. (RT XXIII,
146:1-146:6.) In 1992, the Mono Lake colony represented
about 85 percent of the total population of California
gulls breeding in California. The Mono Lake colony and
the Great Salt Lake colony have supported a large number
of gulls throughout most of their history and during the
extensive drought periods. Other small California gull
colonies were either abandoned or reduced during the
recent six-year drought. (RT XXIII, 146:7-147:1.)
The documented history of the nesting
gull population at Mono Lake is limited. There is a
debate by gull researchers on the reliability and
interpretation of historical population estimates,
particularly regarding changes in the size and
distribution of the gull colony during this century.
(SWRCB 7, Appendix C, p. C-1.) Dr. David W. Winkler
attributes the low gull population in the early part of
this century to large scale harvesting of gull eggs to
supply food to the mining towns. He believes that the
gull population recently has been engaged in a slow
population recovery. (RT XXIII, 166:2-166:19.) Dr.
Winkler suggests that a pristine Mono Lake probably would
have supported many more gulls than were nesting there in
1940. (RT XXIII, 167:1-167:4.)
Dr. Jehl stated that the historical
record indicates that gulls have nested extensively on
Paoha Island at various times. In 1863, the entire Mono
Lake gull population (of unknown size) was on Paoha
Island. In 1916, all of the estimated 2,000 gulls at Mono
Lake nested on Paoha Island. (LADWP 34, Section 2, p.
37.) Dr. Jehl testified that this would indicate that
conditions on Paoha Island are suitable for gull nesting.
(RT XII, 82:8-82:17.) Dr. Jehl also testified, however,
that most of the increase in gull populations from 1940
to 1979 was on Negit Island. Dr. Jehl stated that, in
1976, Negit Island held approximately 75 percent of the
Mono Lake gull population and more than half nested in
the shrub habitat on top of the island. (RT XII,
149:3-149:22.) Mr. Kerry Kellogg, a long-time Lee Vining
resident, recalled boating to Negit Island in the 1950s
to watch the nesting gulls. (NAS&MLC 1J, p. 3.)
Dr. Winkler testified that from 1919 to
1979 the majority of the breeding gulls at Mono Lake
nested on Negit Island. (NAS&MLC AE, point #4.) The
expansion of the Mono Lake gull colonies in the 20th
century happened on Negit Island rather than Paoha Island
even though Paoha Island was available for nesting in
essentially its present state for a large part of that
time. (RT XXIII, 300:9-300:19.) Paoha Island has been
avoided throughout the large expansion of the gull
populations on the islets during the 1980s, probably due
to a resident coyote population. (RT XXIII,
179:18-179:25.) Mr. Shuford of the Point Reyes Bird
Observatory testified that the resident coyote population
on Paoha Island is a major deterrent to nesting. (RT
XXIII, 158:18-159:7.)
The experts disagree regarding the value
of Negit Island's greasewood scrub habitat for gull
nesting. Dr. Jehl testified there is no evidence in the
scientific literature or his field experience that brushy
habitats are preferred. (RT XII, 82:1-82:7.) Dr. Winkler
referred to 1928 photographs of gulls in greasewood scrub
habitat on Negit Island. (NAS&MLC 233 and 234.) Mr.
Shuford acknowledged the difference of opinion and
explained that there have been no studies at Mono Lake
that directly compare reproductive success and gull
habitat preference. (RT XXII, 149:15-149:20.) In any
event, the evidentiary record establishes that Negit
Island and its islets historically have provided
important gull nesting habitat. Dr. Jehl expressed
concern that concentration of the bulk of the colony on a
single island has risks because of predators, spread of
infectious diseases or parasites. He believes the risk is
reduced if the population is dispersed over several
islands. (RT XII, 83:10-83:18.)
As Mono Lake fell below 6,395 feet, the
Paoha islets emerged and became important nesting sites
for gulls during the recent landbridging of Negit Island.
In 1992 and 1993, the Paoha islets held more than 25
percent of the entire Mono Lake gull population. (RT XII,
82:25-83:2.) Dr. Jehl testified that, in 1990, these
islets had higher productivity than any other colony. (RT
XII, 83:4-83:5.) Dr. Beedy testified, that it was his
understanding, that under the 6,383.5 lake level
alternative addressed in the Draft EIR, the Paoha islets
would be planed down (due to wave erosion) causing a
permanent loss of habitat even if the lake level were to
decline again at a later time. (RT VI, 96:6-96:18.) This
problem was addressed in Auxiliary Report 22 to the Draft
EIR. (SWRCB 13v, pp. 13-15.) At the higher range of the
6,377 alternative described in the Draft EIR (6,373 feet
to 6,383 feet), most or all of the current nesting area
on the Paoha islets would be eliminated. (LADWP 34,
Section 2, p. 31.) The water level fluctuations expected
under the LADWP Mono Lake Mangaement Plan would lead to
the same problem.
Since 1979, there have been five major
instances where coyotes have crossed over the landbridge
to nesting islands. In 1979, coyotes crossed to
Negit Island and displaced 33,000 gulls causing total
reproductive failure. Twain islet, the largest of the
Negit islets, becomes land bridged at 6,372 feet.
(NAS&MLC 199.) In 1982, when the lake level was 6,372
feet, Twain Island and the Java islets were visited by
coyotes and at least 30 percent of the gull population
was displaced. (RT XXIII, 151:10-151:24.) Mr. Shuford
testified that new data documents coyotes reaching Java
islet in 1992 at 6,374 feet causing reductions in
reproductive success and, again, in 1993 at 6,375 feet
causing total reproductive failure of the colony. (RT
XXIII, 153:4-153:11 and 161:10-161:15.) Based on the 1982
information, Mr. Shuford and Dr. Beedy expressed
concern that Twain islet is susceptible to access by
coyotes at roughly the same elevation as Java. Currently,
Twain islet holds half of the California gulls breeding
at Mono Lake. (RT XXIII, 153:16-153:21; RT VI,
161:11-162:20.) Recent data indicates that the lake level
may need to be several feet higher than previously
estimated to protect the gull nesting habitat on Negit
Island, Twain islet and the Java islets.
Subcontractors to the EIR consultant
conducted a study of northwest shore coyote populations
in 1990 and 1991 which involved the use of radio collars
on coyotes captured near Negit Island. (SWRCB 13 v,
Auxiliary Report No. 6 to the Draft EIR.)
At least six different adult coyotes
visited Negit Island during the course of the study
during which time the elevation of the lake ranged from
6,375.2 feet to 6,374.5 feet. Two or three coyotes (one
radio collared) were resident on the island from April
23, 1991 to July 15, 1991 which coincides with the gull
nesting and chick rearing period. (SWRCB 13f, p. 13.)
Large quantities of gull remains were found in the
analysis of coyote droppings from Negit Island. In
addition, visual observations and track checks indicated
that there were likely three coyotes on Paoha Island.
(SWRCB 13f, pp. 6-7.)
Of all the factors influencing gull
populations at Mono Lake, Mr. Shuford testified that
predation by coyotes is the one factor to have
demonstrated a clear and major effect on reproductive
success. The evidence shows that there has been a
consistent relationship between lake level and nesting
habitat security from predation. (RT XXIII, 150:23-151:9;
and NAS&MLC 166, Exhibit A.)
Mr. Shuford testified that a lake level
alternative of 6,390 feet or higher would provide the
greatest quantity and security of nesting habitat for
California gulls at Mono Lake. (RT XXIII, 160:18-160:23.)
Dr. Winkler stressed the importance of preserving gull
habitat on Negit Island and recommends a lake level of
6,383.5 feet or higher in order to maintain a sufficient
water barrier around the island. (RT XXIII,
184:16-184:24.) Dr. Jehl believes, however, that the
nesting colony of California gulls at Mono Lake has been
very successful since the start of diversions and would
continue to be successful at the range of water
elevations proposed by LADWP. (LADWP 34, Section 2,
p. 38.) Dr. Jehl acknowledged that, at lake
elevations of 6,390 feet or 6,410 feet, Negit Island
could again support high numbers of California gulls. (RT
XII, 150:8-150:16.)
Mono Lake fluctuates naturally on an
annual basis, typically reaching the yearly maximum level
in late spring or early summer and falling to the minimum
level in late fall. Under the revised LADWP Mono Lake
Management Plan, the Mono Lake target elevation on April
1 of each year would be 6,377 feet. If the lake were
below 6,377 feet, exports from the Mono Basin would not
be allowed. (LADWP 154, p. 7.) Modeling of the LADWP Mono
Lake Management Plan using the Los Angeles Aqueduct
Simulation Model (LAASM) and past hydologic data projects
that Mono Lake would fluctuate around the 6,377 feet
target elevation with a low water level of 6,374.6 feet
during dry hydrologic periods, and a high water level of
6,385.8 feet during wet hydrological periods. (LADWP 154,
Table 8.) Due to the uncertainty of future hydrology, the
water level of Mono Lake may fluctuate over a wider range
than the LAASM output suggests.
Based on the evidence presented, we
conclude that the LADWP Mono Lake Management Plan would
not provide satisfactory long-term California gull
habitat. At the lower water levels projected to occur
under the LADWP Plan, Negit Island, Java islet and Twain
islet would be accessible to predation by coyotes. The
higher water elevations projected to occur under the plan
are likely to erode the Paoha islets due to wave action.
The result would be that when lower water levels again
appear due to periodic fluctuations, there would be
increasingly less habitat available on the Pahoa islets,
and there would be no secure habitat available at Negit
Island, Java islet or Twain islet due to accessibility to
coyotes.
The evidence in the record establishes
the following points should be considered in determining
lake level management criteria which are consistent with
long-term protection of nesting habitat for California
gulls:
1. Coyote predation has been demonstrated
to have a major adverse effect on gull reproduction
success at Mono Lake when island nesting areas become
accessible to coyotes.
2. Java and Twain islets provide good
gull nesting habitat if not accessible to coyotes. Twain
islet currently supports 50 percent of the nesting gull
population at Mono Lake. Recent data show that Java and
Twain islets are likely to be accessible to coyotes
("functionally landbridged") at lake elevations
between 6374 and 6375 feet.
3. Negit Island has historically been a
significant nesting site for California gulls and is
physically landbridged at a lake elevation of 6,375 feet.
4. The water level of Mono Lake
fluctuates in response to hydrologic conditions. During
prolonged droughts, this fluctuation may be several feet
or more.
5. The Paoha islets presently provide
important nesting habitat for gulls. During the rise in
lake elevation which would occur under the 6,383.5 feet
alternative evaluated in the Draft EIR, and which is
projected to occur under the LADWP Management Plan,
however, the Paoha islets will be eroded by wave action.
As a result of the erosion expected during future
increases in lake level, it is unlikely that all of the
remaining Paoha islets would continue to be available for
future nesting habitat during periods when lower water
levels occur.
Based on the evidence in the record, the
SWRCB concludes that a lake level of 6,384 feet would
protect the gulls from coyote access to Negit Island and
nearby islets, and would maintain a buffer for continued
protection during periods of extended drought. A water
level of 6,390 would completely inundate the landbridge
between Negit Island and the shore, and would provide
additional deterrence to potential terrestrial predators.
The SWRCB recognizes that, as the lake rises, the Paoha
islets will be eroded and probably lost as future nesting
habitat. In view of the smaller size and ephemeral nature
of the Paoha islets, however, the SWRCB does not believe
that their protection justifies the loss of the much
larger gull nesting habitat available on Negit Island at
lake levels above 6,384 feet. At a lake level of 6,384 or
higher, gulls will have abundant nesting habitat on Negit
Island and several of the islets.
6.3.4 Caspian Terns
Caspian terns (Sterna caspia) are found
throughout the world. They breed at scattered locations
throughout North America, including the Pacific and
Atlantic Coasts and interior regions as far north as
Canada. Along the Pacific Coast, they nest primarily in
large colonies on human-created habitats. In interior
California, Caspian terns breed at isolated lakes. They
are common on bays, beaches near river mouths and salt
ponds from April to early October and uncommon or rare
the rest of the year. (SWRCB 7, Vol. 2, p. 3F-20.) The
Caspian tern often nests in association with gulls on
open, barren islands. (RT XII, 74:13-74:16.) It is not a
species of special concern, or a candidate species for
listing at the State or Federal level. (RT VI,
101:1-101:11.) The range and population of the species is
increasing in the Pacific states. (RT VI, 101:24-102:1.)
Caspian terns may have been nesting in
the Mono Basin as early as 1963. (RT XII, 74:21-74:25.)
Nesting birds were discovered on Twain islet in 1976. (RT
XXIII, 322:22-323:13.) The terns nested on Twain islet
through 1981. In 1982, the water level of Mono Lake
reached the historic low of approximately 6,372 feet and
coyotes gained access to the islet. (RT XXIII,
305:18-306:7.) The birds shifted to the Paoha islets
where they have nested with varying success. (RT VI,
101:20-101:23.) After the lake rose in 1986, the terns
returned to Twain islet and nested along with the gulls.
(RT XII, 146:6-146:15.) Between 1976 and 1993, the number
of breeding pairs varied from one to approximately 13.
(RT XII, 142:5-142:7.) LADWP Exhibit 34 provides a
summary prepared by Dr. Jehl of the population and
nesting success of Caspian terns at Mono Lake. (LADWP 34,
Section 2, p. 32.) Based on that data, the Draft EIR
characterizes the Mono Lake population as highly variable
and probably sustained by immigration rather than local
reproduction. (SWRCB 7, Vol. 2, p. 3F-21.)
Dr. Jehl testified that at the higher
range of the 6,377 feet alternative and at the higher
alternatives, most or all of the current nesting area on
the Paoha islets will be eliminated. (LADWP 34, Section
2, p. 31.) Loss of tern habitat would also be expected to
occur under the range of water levels projected to occur
under the LADWP Management Plan. (RT XXIII,
310:10-310:25.) Caspian terns nest about two to three
feet apart. Dr. Jehl estimated that a maximum of 250
square feet of nesting area would be required for the
existing population. (RT XII, 175:9-175:19.)
Dr. Beedy testified that the Draft EIR
did not analyze the impact to Caspian terns of rising
lake levels because there is no clear impact to the
species, they are not a listed species or species of
concern, and there is no reason to believe that the terns
would not shift back to the Negit islets if the Paoha
islets were inundated. (RT VI, 100:2-102:16.) Dr. Jehl
agreed that Caspian terns are not rare, and the loss of
Mono Lake as a nesting area would have no effect on the
species as a whole, but suggested that potential effects
on Caspian terns should be considered. (RT XII,
76:10-76:16.)
Dr. Winkler testified that at the water
elevations the SWRCB was considering, terns will not be
impacted. As long as there is gull nesting habitat on
Twain islet, there will also be nesting habitat for
terns. The area that Dr. Winkler identified as the
former nesting site for terns on Twain islet (NAS&MLC
236) is at an elevation of about 6,415 feet. (RT XXIII,
323:14-324:2.)
6.3.5 Eared Grebes, Red-necked
Phalaropes and Wilson's Phalaropes
Eared grebes (Podiceps nigricollis),
Wilson's phalarope (Phalaropus tricolor),
and the red-necked phalarope (Phalaropus lobatus)
are birds that use the open water of Mono Lake.
Eared grebes are widespread in North
America, Eurasia and Africa. In California, eared grebes
breed in marshy habitats in the Central Valley,
northeastern plateau, and the Great Basin including
Crowley Lake, but not at Mono Lake. Most eared grebes
migrating through the state winter at the Salton Sea or
in the Gulf of California. (SWRCB 7, Vol. 2, p. 3F-22.)
The nearly one million eared grebes at Mono Lake comprise
the majority of the Western Hemisphere population. The
eared grebe is the most abundant bird species at Mono
Lake. Grebes are totally reliant on the aquatic
productivity of the lake and may remain continuously at
the lake for up to eight months. (RT XII, 77:1-77:13.)
Dr. Jehl testified that even at the
historic low water level of 6,372 feet, the available
food supplies were more than adequate to support the
population. (RT XII, 77:21-77:25.) Dr. Jehl states that
when shrimp density gets down to approximately 3,000 per
square meter, the birds leave the lake. This may occur as
early as November or as late as February. In Dr. Jehl's
opinion, food resources for grebes are not a matter of
concern at any of the lake levels under consideration.
(RT XII, 79:5-79:19.)
The red-necked phalarope breeds in arctic
regions worldwide. During migration through California,
red-necked phalaropes are common to very abundant
depending upon the season. This species is especially
abundant in interior lakes such as Mono Lake during the
fall. Female migrating red-necked phalaropes arrive at
Mono Lake by mid-July and are followed in succession by
the males and juveniles. The numbers in the Mono Basin
reach a peak by mid-August. Individual red-necked
phalaropes are believed to stay from one week to several
weeks at Mono Lake. Dr. Jehl estimated total populations
at Mono Lake ranged between 52,000 and 65,000 from 1981
to 1984. (SWRCB 7, Vol. 2, p. 3F-26.) Daily census data
collected by teams of observers estimated the peak daily
count at 17,536 on September 16, 1990. The peak count was
approximately 18,000 on August 11, 1991. Dr. Margaret
Rubega's analysis of the available population data
suggests that the total number of red-necked phalaropes
using Mono lake as a migratory stopover probably has
changed little since the early 1980s. (SWRCB 13k, pp.
22-23.)
Red-necked phalaropes feed primarily on
alkali fly larvae and to a lesser degree on pupa and
adults. Dr. Jehl testified that he has not been able to
determine any long-term effects on red-necked phalaropes
that can be attributed to changes in lake level or
salinity. (RT XII, 89:11-89:25.) Recent work by Dr.
Rubega suggests there may be a relationship between
alkali fly densities at Mono Lake and success of
red-necked phalaropes. Dr. Rubega concludes that lake
levels which maximize alkali fly production are likely to
benefit red-necked phalaropes. (SWRCB 13k, pp. 1-2.)
The report prepared by Dr. Rubega
expresses concern that the distribution of red-necked
phalaropes at Mono Lake in recent years has shifted
toward the northeast sector of the lake which is not as
accessible to viewing by the general public. (SWRCB 13k,
p. 2.) Dr. Jehl testified that there is no simple pattern
of phalarope distribution as a function of lake level,
and there is no obvious pattern under conditions that
have already been studied. Therefore, it is impossible to
predict distribution of the birds at lake levels that
have not yet been observed. (RT XII, 84:22-86:4.)
There was no substantial long-term evidence presented
that linked phalarope use of particular areas of the lake
to the water level present at a particular time. In any
event, the SWRCB does not consider the relative ease of
viewing the phalaropes present at different locations on
Mono Lake to be a significant factor to be considered in
determining an appropriate lake level.
The breeding range of the Wilson's
phalarope is from British Columbia east to Manitoba and
south to California. Females compose approximately 70
percent of the Wilson's phalaropes at Mono Lake. The
females arrive at Mono Lake in mid-June, followed by
smaller numbers of males (28 percent) in early July and
juveniles (2 percent) in late July and early August.
Adult Wilson's phalaropes remain at Mono Lake
continuously for 30 to 40 days to molt and accumulate fat
reserves. (SWRCB 7, Vol. 2, pp. 3F-30 to 3F-31.)
Wilson's phalaropes differ from red-necked phalaropes in
their food habits. The females tend to concentrate in
open water where they forage for brine shrimp and smaller
amounts of alkali pupae. Males forage closer to shore and
consume a greater proportion of flies. Alkali flies also
predominate in the juvenile's diet. (SWRCB 7, Vol. 2, p.
3F-31.) After refueling at Mono Lake, Wilson's phalaropes
fly 3,000 miles nonstop to wintering grounds in southern
Bolivia, northern Chile, and Argentina. (SWRCB 7, Vol. 2,
p. 3F-29.) Between 1980 and 1986, the annual flock was
estimated at between 50,000 and 60,000 individuals.
Recent estimates have reported lower populations. (SWRCB
7, Vol. 2, p. 3F-29 to 3F-30.)
The same general concerns expressed about
lake level and aquatic productivity relative to
red-necked phalarope populations at Mono Lake would
pertain to Wilson's phalaropes, but are of greater
concern for Wilson's phalaropes. (See Section 6.1.) Mono
Lake is one of the world's most important migratory
staging areas for Wilson's phalarope. No similar habitats
exist in the vicinity of Mono Lake which provide
dependable food supplies and staging areas for birds
migrating through the western Great Basin. (SWRCB 7,
Vol. 2, p. 3F-32.) Because of Mono Lake's importance
to migrating shorebirds, it was designated as one of 18
reserves in the Western Hemisphere Shorebird Reserve
Network. The testimony of Dr. Jehl indicates that a
rising lake, up to historic levels, probably would not
have a long-term adverse effect on the populations of
phalaropes at Mono Lake. (RT XII, 124:3-124:16.)
6.3.6 Snowy Plovers
Western snowy plovers (Charadrius alexandrinus)
are a federal candidate for listing as threatened or
endangered. The population at Mono Lake has regional
significance as one of the state's most important
breeding concentrations. (SWRCB 7, Vol. 2, p. 3F-36.) The
species' breeding range extends across much of North
America, Eurasia, and portions of South America. In North
America, snowy plovers breed along the Gulf Coast and
Pacific Coast from Washington to California. In
California, snowy plovers nest along the coast and in
interior locations such as Owens Lake, the Salton Sea and
Mono Lake.
Recent surveys of western North America
estimate 7,800 breeding adults at interior locations and
about 1,900 adults along the coast. (SWRCB 7, Vol. 2, p.
3F-33.) Dr. Winkler first recorded nesting snowy plovers
at Mono Lake in 1977, and estimated at least 10 nesting
pairs and more than 100 total birds during fall
migration. In 1978, statewide censuses estimated the Mono
Lake population represented approximately 11 percent of
California's breeding population. (SWRCB 7, Vol. 2, p.
3F-34.) Snowy plovers nest in alkali flat and sand dune
habitats around the eastern half of the Mono Lake and a
small population exists along the northwestern shore near
County Park. Their nesting season extends from mid-April
to mid-July. (SWRCB 7, Vol. 2, p. 3F-35.)
The Draft EIR reports that declining lake
levels have expanded the area of potential breeding
habitat to more than 10,000 acres. Lake levels expected
at the 6,377 feet alternative and higher elevations would
inundate increasingly greater proportions of that habitat
raising the concern that snowy plovers could be adversely
impacted. In 1989, however, approximately 75 percent of
the available habitat was not occupied and thousands of
acres could be inundated without causing adverse impacts
on snowy plovers. (SWRCB 7, Vol. 2, p. 3F-87.) Testimony
from several expert witnesses supports the conclusion
that a rise in the lake level to 6,390 feet or higher
would leave ample habitat available for snowy plovers.
(RT XII, 206:3-206:21; RT XIII 318:18-320:1; RT XIII
320:2-320:22.)
6.3.7 Waterfowl
Detailed and colorful testimony from long-time residents
of the Mono Basin shows that Mono Lake once supported
tens of thousands of ducks (possibly hundreds of
thousands) and hundreds of geese during the fall
migration period. The most abundant species was the
northern shoveler (spoonbill) that used the lake to
forage on brine shrimp. Mallards were also numerous and
were generally associated with freshwater sites along the
streams, springs, and fresh and brackish marshes. Sites
which received heavy waterfowl use were the meadows area
of Rush Creek, Rush Creek near its mouth, the Dumbrowski
Ponds on Rush Creek, the Lee Vining Creek delta, the
marshes at Simons and Warm Springs, the northshore
lagoons, and wetlands near Wilson Creek and Dechambeau
Ranch. There were also many ducks in Rush Creek above
Grant Lake. (RT XVII, 185:21-186:10.)
The hearing testimony is consistent with
interviews of several other long-time residents of the
Mono Basin which are reported in the Draft EIR discussion
of Mono Basin waterfowl. (SWRCB 7, Vol. 2, p. 3-7.)
Historic waterfowl abundance at Mono Lake is also
supported by a 1940 waterfowl harvest map of Mono Lake
(DFG 95) and the Pacific Waterfowl Flyway Report, #7,
1949. (DFG 96; RT XXI, 40:23:-41:20.)
NAS&MLC Exhibit 103 is composed of
Pacific Flyway Waterfowl Investigation population data
sheets from September through November of 1948 for Mono
Lake. The data were collected by Walter Dumbrowski who
owned the commercial waterfowl hunting club referred to
in the testimony of long-time residents. His counts on
several September days estimated 175,000 to 200,000
ducks. His October counts ranged from approximately
175,000 to approximately 400,000 ducks. His November
counts estimated over a million ducks of which 80 percent
were shovelers and ruddy ducks. Attached to NAS&MLC
Exhibit 103 is a map of the Rush Creek delta depicting
the location and size of the Dumbrowski ponds. The
largest of these ponds (22 acres) is identified (shaded)
as the area of eye count observation reported on the
September 20, 1948 data sheet where Mr. Dumbrowski
estimated there were between 175,000 and 200,000 ducks.
On October 11, 1948, he estimated there were about 60,000
ducks in the pond.
Retired DFG Biologist Elden Vestal
testified that migratory waterfowl were present in large
numbers at Mono Lake from October through December.
Although he did not participate in formal waterfowl
counts at Mono Lake, Mr. Vestal observed hundreds of
thousands of waterfowl on Mono Lake on numerous
occasions. Shovelers and ruddy ducks were the predominant
species but he also observed mallards, pintails,
redheads, gadwalls, baldpates (American widgeon), scaups,
coots, three species of teal and Canadian geese.
Mr. Vestal confirms that there was extensive duck
hunting around Mono Lake in the 1930s and 1940s.
(NAS&MLC 1AB, pp. 2-5.)
Dr. Stine testified that a drawing
prepared by Walter Dumbrowski in the mid-1940s which
identifies sites of waterfowl distribution on Mono Lake
coincides with areas where freshwater enters Mono Lake.
(RT XXI, 13:15-15:3; and NAS&MLC 176.) Dr. Stine
attributed waterfowl abundance at these areas to the
previously discussed phenomenon of hypopycnal
stratification which occurs where freshwater enters Mono
Lake. (RT XXI, 20:4-20:16.) In addition to Mono Lake and
immediately adjacent areas, Dr. Stine testified that the
North shore lagoons and the Rush Creek bottomlands were
areas of duck abundance. (RT XXI, 9:15-10:7.) The
declining water elevation of Mono Lake affected all three
areas identified by Dr. Stine. The lagoons dried up as
the declining water level approached 6,400 feet. (RT XXI,
27:4-27:22.) The marshlands of the Rush Creek and Lee
Vining Creek deltas were lost due to incision. (RT XXI,
28:11-29:9.) Although there has been a net increase in
marshland, most of the presently existing marshland is
not adjacent to the lake. (RT XXI, 29:10-29:15.)
DFG biologist Ron Thomas testified that
he has flown over the lake many times and hunted there on
several occasions. He believes that Warm Springs and
Simons Springs are probably the major waterfowl
concentration areas today due to their location near to
the lake. (RT XXI, 39:24-40:13.) Mr. Thomas testified
that the habitat value of the new wetland areas is very
much diminished from the previous habitats. (RT XXI,
53:2-53:11.)
Dr. Beedy testified that the lake
fringing alkali meadows supported very few ducks. (RT VI,
135:17-135:22.) Dry meadow areas provide little waterfowl
value in the absence of a source of fresh water. (RT VI,
137:20-138:18.) Botanist James Jokerst testified that not
all habitats classified as wetlands or riparian
necessarily have the same values and functions. (RT VI,
113:12-113:19.) Mr. Jokerst testified that not all of the
lake fringing "wetlands" may meet regulatory
definitions of wetlands. The U.S. Army Corps of Engineers
requires that jurisdictional wetlands have three
indicators: prevalence of hydrophytic vegetation, wetland
hydrology, and hydric soils. In contrast, Mr. Jokerst
explained that the USFWS requires presence of only one of
the positive indicators to be classified as a wetland.
Large portions of the alkali flat qualify under the USFWS
definition because the water table is at or near the
surface for a substantial portion of the year. Only small
areas of alkali flat, with very sparse vegetation, meet
the Corps of Engineers wetlands criteria. The relicted
areas that are vegetated today were submerged in 1940.
(RT VI, 217:14-219:2.)
Dr. Frederic Reid (Biological Supervisor
for Ducks Unlimited) testified that the Mono Basin, like
most of the wetlands in the Great Basin, is an important
migrational habitat. (RT XXI, 60:6-60:8.) He stated that
the Klamath, Mono and Owens Valley waterfowl habitats
have been impacted by human activity including
agriculture drains, water diversions and water quality
degradation. (RT XXI, 62:13-62:16.) Dr. Reid believes
that the pre-diversion conditions of Mono Lake supported
orders of magnitude more waterfowl than exist today. (RT
XXI, 69:1-69:3.)
The Draft EIR discusses the decline of
migratory duck populations across North America during
the 1970s and 1980s. Populations at Mono Lake reflected
this trend. Censuses conducted at the lake during the
1970s and 1980s suggest that no more than a few thousand
ducks were present at Mono Lake at one time. (SWRCB 7,
Vol. 2, p. 3F-39.) Current estimates of duck populations
at Mono Lake range from 11,000 to 15,000 individuals per
year. Recent operation of Grant Lake for water supply and
recreation has reduced its waterfowl habitat value.
(SWRCB 7, Vol. 2, p. 3F-43.)
Dr. Stine testified regarding what he
believes would be required to restore waterfowl habitat
in several areas including the following: (1) Restoration
of waterfowl habitat at Warm Springs and Simon Springs
would require a lake level of 6,390 feet;
(2) Restoration of waterfowl habitat along Rush
Creek would require rewatering of abandoned channels and
raising the water table of the Rush Creek bottomlands;
(3) Restoration of the marshland and waterfowl habitat
areas at the Rush, Lee Vining, and Mill Creek deltas and
the Dechambeau Ranch embayment would require a water
level of 6,400 feet; and (4) Restoration of the north
shore lagoon would require a water level of 6,405 feet.
(NAS&MLC 1U, p. 7.)
Dr. Reid testified that, at the current
lake level or below, waterfowl habitat restoration will
be expensive and marginal in impact. Substantial
improvements can only be achieved by increasing the water
level. (RT XXI, 72:11-72:22.) Dr. Reid's testimony
regarding the lake levels required for restoration of
waterfowl habitat in specific areas is consistent with
Dr. Stine's analysis. Dr. Reid also testified regarding
the benefits of riparian restoration work to improve
waterfowl habitat in the area of Mono Basin streams,
springs and deltas. (RT XXI, 73:14-73:21.) Mr. Thomas
testified that naturally fluctuating lake levels around
6,405 feet or higher would restore the waterfowl
populations that have been seen in the past. (RT XXI,
54:22-54:24.)
Dr. Reid described the North American
Waterfowl Plan which arranges partnerships between
governmental agencies and private conservation
organizations to restore wetland habitats to support the
waterfowl population levels of the 1970s. Ducks Unlimited
was involved in several projects in the Great Basin. (RT
XXI, 74:2-74:21.) Dr. Reid identified measures that could
be implemented at Warm Springs and Simons Springs to hold
water through the summer periods and into the fall. (RT
XXI, 154:1-154:12.) Dr. Reid also testified that Ducks
Unlimited is cooperating on a 30-acre wetland restoration
project at DeChambeau Pond, but stated that such projects
can be very costly. (RT XXII, 25:7-25:19.) Dr. Reid
described the potential use of "scrapes" to
collect water and emulate slough-like depressions or
swales to hold water for the summer and sometimes into
the fall. (RT XXII, 35:15-36:2.) He believes the areas of
greatest potential to create or restore habitat are at
Warm Springs, Simons Springs and the stream corridors and
floodplains of Rush Creek and Lee Vining Creek. (RT XXI,
154:1-154:25.) Dr. Reid testified that the
substantial planning process for wetlands restoration can
typically run about 18 months. (RT XXII,
47:16-49:5.) Ducks Unlimited would be willing to
participate as a technical advisor on waterfowl habitat
restoration. (RT XXI, 155:7-155:9.)
Based on the evidence discussed above,
the SWRCB concludes that Mono Lake and nearby areas
provided important habitat and a major concentration area
for migratory waterfowl prior to out-of-basin diversions
by LADWP and up to the early 1960s. The loss of open
water habitats and fresh water sites around the lake due
to water diversions by LADWP coincided with the decline
in migratory waterfowl populations at Mono Lake.
Historically, Mono Lake probably supported several
hundred thousand ducks during the fall migration. The
current habitat supports a small fraction of the historic
numbers.
Restoration of pre-diversion waterfowl
habitat would permit substantial increases in migratory
waterfowl use at Mono Lake. The actual number of
waterfowl which would use these restored habitats,
however, is unknown and is dependent in part upon the
restoration of other similarly degraded habitats in the
interior portion of the Pacific Flyway and annual
fluctuations in waterfowl reproduction and populations.
Maximum restoration of waterfowl habitat in the Mono
Basin would require maintaining a water level of 6,405
feet.
In view of the City of Los Angeles' need
for water for municipal use (Sections 7.1 through 7.1.7
below), and in view of the competing public trust uses
which would not be best served by a water level of 6,405
feet, this decision does not regulate LADWP's water
diversions in a manner which would restore the maximum
amount of waterfowl habitat. Increasing the water level
to an average of 6,392 feet as called for in this
decision, however, would allow for restoration of some of
the lost waterfowl habitat. Additional waterfowl habitat
could be restored through other restoration measures
identified in the record.
Permanent termination of all or virtually
all water exports from the Mono Basin would be needed to
restore the maximum amount of waterfowl habitat in the
Mono Basin, but would preclude use of any water for
municipal use by Los Angeles. In accordance with the
"physical solution doctrine" discussed in
Section 2.5 above, a water diverter can be compelled to
employ a physical solution through which competing water
demands can be met and the constitutional goal of
promoting maximum beneficial use of the State's waters
will be served. Thus, as part of a physical solution
allowing for diversion of water for municipal use, LADWP
can be required to undertake waterfowl habitat
restoration measures. Waterfowl habitat restoration can
serve to restore public trust uses while requiring a
smaller commitment of water.
With the exception of the natural
restoration that gradually will occur due to the instream
flows and lake level required by this decision, the
record is insufficient to specify at this time the
waterfowl habitat restoration measures which should be
undertaken. The record is sufficient, however, to require
that as part of the restoration plan required by this
decision, LADWP consider various waterfowl habitat
restoration measures identified in the Draft EIR and the
hearing record. The SWRCB concludes that LADWP should be
required to consult with DFG and other interested parties
and analyze potential feasible waterfowl restoration
projects which are consistent with the lake level
criteria established in the decision, consistent with the
regulations governing the Mono Basin National Scenic
Area, and which could avoid or properly mitigate any
disturbance of archeological resources in the Mono Basin.
LADWP's evaluation of potential waterfowl restoration
projects should focus on lake-fringing wetland areas.
6.3.8 Special-Status Species
Special-status species are animals and plants that are
legally protected under the State or Federal Endangered
Species Acts or other regulations, species that are
considered sufficiently rare by the scientific community
to be candidates for such listing, and species of special
concern to either state or federal agencies. (SWRCB 7,
Vol. 2, pp. 3F-12 to 3F-13.) The Draft EIR identified 39
special-status animal species that occur or may occur in
the Mono Basin or along the upper Owens River to Lake
Crowley. Appendix E of the Draft EIR provides an analysis
of the pre-diversion and point-of-reference status of the
39 species. The California gull, the snowy plover, and
the Mono Lake brine shrimp have been discussed
previously. Of the remaining 36 special-status species,
the Draft EIR concludes:
1. Ospreys and bald eagles would probably
benefit from restoration of fisheries on Rush and Lee
Vining Creeks;
2. Reductions of spring flows, grazing in
the Mono Basin and construction of Lake Crowley probably
reduced habitat availability for yellow rails, which
prefer to nest in shallow, freshwater marshes with sparse
emergent vegetation; and
3. Long-eared owls, yellow warblers,
yellow-breasted chats, and willow flycatchers probably
declined in the project area during the diversion period
due to a loss of riparian broadleaf and willow scrub
vegetation along the diverted tributaries. (SWRCB 7, Vol.
2, p. 3F-49.)
The Draft EIR identified six
special-status plants that are known to occur below the
7,000-foot elevation in the Mono Basin. The Draft EIR
concludes that no state listed or federally listed or
proposed threatened or endangered plants would be
affected by any of the alternatives. In addition, no
special-status plants in the Mono Basin or Long Valley
occur in riparian zones affected by the project. Two
plants listed in the California Native Plant Society
inventory of rare and endangered plants could be affected
by an increase in lake level above 6,400 feet. All
special-status plants in the Mono Basin and Long Valley
were probably more abundant in 1940 than today, but they
have not been adversely affected by changes in streamflow
or lake levels. (SWRCB 7, Vol. 1, pp. 3C-48 to
3C-49.)
In summary, the minimum streamflow and
lake level criteria established in this decision will
benefit Mono Lake brine shrimp and California gulls, may
have some beneficial effect on ospreys and bald eagles,
and are not expected to have a significant adverse impact
on any special status species of animals or plants.
6.4 Mono Basin Air Quality
As noted earlier in this decision, the California Supreme
Court ruled that the scenic views of Mono Lake and its
shore, and the purity of the air in the Mono Basin are
among the values protected by the public trust doctrine.
(National Audubon Society v. Superior Court,
33 Cal.3d at 435, 189 Cal.Rptr. at 356.) The declining
water level of Mono Lake attributable to LADWP diversions
has led to severe periodic dust storms, a deterioration
of air quality in the Mono Basin and violation of
standards set pursuant to the federal Clean Air Act. As
discussed below, the evidence in the record establishes
that resolution of the air quality problem will require
reduced water diversions from pre-1989 levels in order to
allow the water level of Mono Lake to rise and cover much
of the exposed lakebed area.
LADWP argues that the Legislature
"has not granted the SWRCB authority to enforce
state or federal statutes involving air quality."
(LADWP Rebuttal Brief, p. 65.) The fact that the
Legislature has charged other agencies with primary
regulatory authority over air quality, however, does not
mean that the SWRCB should ignore existing or potential
air quality impacts of water diversions. As noted above,
the Audubon decision establishes that air quality
is among the values protected by the public trust
doctrine. Moreover, all water diversions in California
are subject to the constitutional prohibition of
unreasonable use or method of diversion of water.
(California Constitution, Article X, Section 2.) It
should be beyond dispute that, in a situation where
diversion of water can lead to violation of a public
health based air quality standard, the protection of air
quality should be considered in determining the
conditions under which the water appropriation is
allowed. Statutory restrictions upon the Great Basin Air
Pollution Control District's jurisdiction to regulate
water diversions cannot logically be interpreted as
limiting the SWRCB's established statutory authority over
diversion and use of water. (Water Code Sections 174,
1200, et seq.)
6.4.1 Effect of Reduced Lake Levels on
Air Quality
No ambient air quality monitoring was conducted in the
Mono Basin before 1979. Therefore, no quantitative data
exist to describe the pre-1941 conditions. The Draft EIR
(SWRCB 7, Vol. 2, pp. 3H-8 to 3H-11 and Appendix N, p.
N5-7) reviewed the historical accounts of the Mono Basin
including an 1889 report titled "Quaternary
History of the Mono Valley, California" by
Israel C. Russell (reprinted from the Eighth Annual
Report of the United States Geological Survey, 1889, pp.
267-394). Russell noted that on windy days Mono Lake was
streaked with alkaline froth, but his report makes no
mention of windblown dust, sand or salt. (SWRCB 7,
Vol. 2, pp. 3H10-3H11.)
Aerial photographs from 1930 (lake
elevation approximately 6,420) and 1940 (lake elevation
approximately 6,417) show very narrow fringes of
efflorescent salts along the edges of lagoons near the
lakeshore; scattered small patches of salt among some
sand dunes; and no efflorescent salt visible on the
narrow strip of barren sand bordering the north or east
shores of the lake. (SWRCB 7, Vol. 2, p. 3H-9.) The Draft
EIR states that the best available evidence suggests that
major dust storm events were probably rare under
pre-diversion conditions and that any dust storms that
did occur would have been dominated by silt, clay, and
sand particles with only small quantities of salt
particles from interstitial salts and water spray from
off the lake. (SWRCB 7, Vol. 2, p. 3H-11.)
As the surface elevation of Mono Lake has
fallen from 6,417 feet at the start of LADWP diversions
in 1941 to 6,375 feet in spring of 1994, increasingly
greater areas of former lakebed and lakebed sediments
have been exposed ("relicted") forming a white
ring around Mono Lake known as the playa. Under present
conditions with large areas of exposed playa, strong
winds produce dust storms of varying size and duration
that degrade the ambient air quality and scenic views of
the Mono Basin. The three most frequent dust emission
source areas are the landbridge (the exposed playa
between the shoreline and Negit Island), the North Shore
and the East Shore. (GBUAPCD A, p. 7.) An additional
emission source area is the emerged western portion of
Paoha Island. (SWRCB 7, Vol. 2, pp. 3H-20 and 21.)
The Draft EIR describes the term
"dust storm" and "sand storm" as
episodes of windblown particulate matter that
significantly restrict visibility. Dust storms are
dominated by particles with diameters smaller than 100
microns; sand storms are dominated by particles with
diameters larger than 100 microns. (SWRCB 7, Appendix N,
p. N-10.)
The major emission sources of suspended
particulate matter in the Mono Basin are produced by wind
erosion of efflorescent salt deposits and some exposed
soils, and sediments. (RT VI, 201:4-201:12.) Efflorescent
salts form as shallow saline ground water rises to the
surface of permeable sediments through capillary action
and evaporates at the soil surface leaving a highly
erodible salt crust. (GBUAPCD 30, pp. 1, 2, 16, and 17,
photographs). Efflorescent salt deposits are seldom found
on soil-air interfaces where the ground water table is
more than ten feet below the ground surface. (GBUAPCD 30,
pp. 1 and 11; SWRCB 7, Vol. 2, p. 3H-21.) The
major emission sources at Mono Lake are considered
"anthropogenic", a classification which
includes emissions influenced directly or indirectly by
human activity. (SWRCB 7, Vol. 2, p. 3H-6.)
6.4.2 The PM-10 Standard and Human
Health
The term "ambient air quality" refers to the
atmospheric concentration of a specific compound or
material present at a location that may be some distance
from the source of the pollutant emissions. (SWRCB 7,
Vol. 2, pp. H-1 and H-2.) During the 1980s, air quality
standards for particulate matter were revised to apply
only to "inhalable" particles with a size
distribution weighted toward particles having aerodynamic
diameters of 10 microns or less ("PM-10").
(SWRCB 7, Appendix, p. N-3.) The PM-10 standard is set to
control concentrations of inhalable sized fine particles
less than 10 microns in size, or about one tenth the
diameter of human hair. (GBUAPCD A, III, p. 17.) Health
risk studies were used to establish the PM-10 standard
based on potential impacts to human health. (RT XII,
9:8-9:22 and 52:6-52:13.)
PM-10 sized particles are small enough to
be inhaled deep into the lower respiratory tract. When
breathing through the nose, few particles with an
aerodynamic diameter larger than 10 microns reach the
lower respiratory tract. (SWRCB 7, Appendix, p. N-3.)
People who live in or visit areas exposed to the dust
events at Mono Lake are at risk.
Federal standards for suspended
particulate matter (PM-10) have been set for two time
periods: a 24-hour average and an annual average of
24-hour values. The federal "National Ambient Air
Quality Standards" (NAAQS) for PM-10 are:
150 micrograms/cubic meter as a
24-hour average; and 50 micrograms/cubic meter as an
annual arithmetic mean (SWRCB 7, Vol. 2, p. 3H-4; RT
XII, 9:23-10:3.)
Dr. M. Joseph Fedoruk, M.D., testified on
behalf of LADWP that there was no evidence that, at the
existing lake levels, the occasional dust storms will
have a significant public health impact in the affected
areas. (LADWP 47, Section 6, p. 87.) Dr. Fedoruk
suggested it is likely that individuals in the affected
area will limit their exposure to PM-10 by taking
avertive action, such as going indoors during the
occasional dust storms. (LADWP 47, Section 6, p. 88.)
After hearing the description of dust problems
experienced by a resident on the north shore of Mono Lake
(NAS&MLC 1F), however, Dr. Fedoruk agreed that
experiences of the type described would constitute a
public health problem. (RT XXIII, 41:10-41:20.)
Mr. Duane Ono of the Great Basin Unified
Air Pollution Control District (GBAPCD), testified that
exposure to PM-10 levels above the federal standard may
cause sensitive individuals to experience varying degrees
of breathing difficulties, some of which may linger
beyond the exposure period. In some cases, breathing
difficulties due to PM-10 exposure may cause asthma
attacks or even contribute to an individual's death.
Other health effects such as eye and nasal irritation may
also occur. The most sensitive population includes
children, the elderly, and people with respiratory
problems, heart disease or influenza. (GBUAPCD A, III, p.
16; RT XXIX, 27:20-27:24.) The U.S. Forest Service is
concerned that exposure to dust events poses a potential
health risk to visitors to the Mono Basin. (RT XXIX,
20:20-20:25.)
6.4.3 Existing Air Quality Conditions
Efflorescent salt deposits at Mono Lake are found along
the northern and eastern shores of the lake, generally
below the 6,390 foot contour. (SWRCB 7, Vol. 2, Figure
3H-20.) Efflorescent salts which were virtually
nonexistent before 1941 cover 4,975 acres or
approximately 65 percent of the relicted lands at lake
elevation 6,376 feet. Some of the salts are
noncrystalline powdery deposits highly susceptible to
wind erosion. More often, the salts are crusted but
subject to disturbance by windblown sand. (SWRCB 7, Vol.
2, p. 3H-21; GBUAPCD 7, 17, 18, and 19 (photographs).)
Windblown emissions at Mono Lake vary
with season due to snow cover, precipitation, and crust
formation. Generally the dust episodes occur during the
months of April, May, June, November and December when
the surface crust of the playa is thin. (GBUAPCD 10, pp.
3 and 5; RT XXIX, 20:9-20:11.) U.S. Forest Service
Exhibit 3 is a video of dust events as seen from the Mono
Lake Visitor Center in the spring of 1993.
Documented dust events have caused
short-term air quality degradation in the Scenic Area
which has resulted in exceedences of the Federal standard
for PM-10. However, sampling data suggest that in Lee
Vining (which is normally upwind of the dust storms),
PM-10 concentrations over a 5 year period were extremely
low during all the dust storms. (RT XXIX, 103:1-103:12.)
Dust events have occurred at a frequency and
concentration in violation of the Federal Clean Air Act.
(GBUAPCD A, p. 1.) Mr. Ono testified that GBUAPCD
monitoring data at the Simis Ranch show a statistical
average of about 3.2 exceedences per year for the period
1988 to 1992. (RT XXIX, 53:12-53:19.) The national
ambient air quality standard for PM-10 allows one
exceedence or less per year without regard to how much
the level is above the measured numerical standard of 150
micrograms per cubic meter. (RT XXIX, 29:2-29:15.) While
the air quality of the Mono Basin is normally within the
standard, there are enough days over the standard during
the three-year period to be in violation. (RT XII,
14:3-14:8.)
6.4.4 Compliance with Federal Clean
Air Act Requirements
Designation as a Nonattainment Area: On July 16,
1993, the U.S. Environmental Protection Agency (U.S. EPA)
published a notice of proposed rulemaking revising the
PM-10 designation for the Mono Basin in the Federal
Register. (Vol. 58, No. 135, pp. 38331-38333.) The U.S.
EPA proposed to revise the PM-10 designation for the Mono
Basin from "unclassifiable" to
"nonattainment" based upon recorded violations
of the PM-10 NAAQS which occurred on or after January 1,
1989. (USEPA 1, p. 1.) The Mono Basin was designated as a
nonattainment area for PM-10 on December 29, 1993. (RT
XXIX, 28:11-28:19.)
The Regulatory Framework: The
federal Clean Air Act amendments of 1990 require each
state to develop, adopt, and implement a State
Implementation Plan (SIP) to achieve, maintain, and
enforce federal air quality standards throughout the
state. These plans must be submitted to and approved by
the U.S. EPA. The NAAQS for PM-10 sets forth regulations
for implementing the regulatory standards by requiring
the development of a SIP to develop strategies necessary
to assure attainment and maintenance of the PM-10
standard. (USEPA 1, p. 1.) Designation as a nonattainment
area sets up a series of planning and regulatory deadline
requirements for the state and local air pollution
control agencies. By operation of law, the Mono Basin is
initially classified as a moderate nonattainment area.
The State must submit a SIP to U.S. EPA within 18 months
that either demonstrates attainment will occur no later
than the end of the sixth calendar year following the
effective date of redesignation or shows that a
demonstration of attainment within that period is
impracticable. (RT XII, 5:11-5:22; USEPA 1, p. 3.)
Demonstration of practicable attainment may include the
use of air quality models. (USEPA 1, p. 3.)
If the State does not demonstrate
attainment or demonstrates that attainment is
impracticable within six years from the designation date
(December 29, 1993), the Mono Basin will be upgraded to
the serious nonattainment classification by U.S. EPA.
This redesignation provides additional time to attain the
standard, while also triggering additional legal and
planning requirements. A new SIP is required within 18
months that demonstrates attainment as expeditiously as
practicable, but in no case later than ten years after
the designation to serious nonattainment area. In a
December 16, 1993 letter to GBUAPCD (NAS&MLC 246),
U.S. EPA outlined its understanding of the general
timelines for the longest period possible for compliance
with planning deadlines and attainment deadlines. The
letter states that if the Mono Basin fails to attain
PM-10 standards by December 31, 2008, a new SIP would be
required that provides for a 5 percent reduction of PM-10
emissions per year until the NAAQS is attained.
(NAS&MLC 246, p. 2.) If the State fails to provide an
adequate SIP, U.S. EPA is required to promulgate its own
federal implementation plan to achieve the attainment of
the PM-10 standard in the Mono Basin. (RT XII, 6:10-7:7.)
The State has designated the GBUAPCD as
the lead agency to develop the SIP for the Mono Basin.
Once the plan is completed and approved by the GBUAPCD,
it will be forwarded to the California Air Resources
Board (ARB) for adoption. Once adopted by ARB, the plan
is considered as a SIP which is then forwarded to the
U.S. EPA in accordance with Clean Air Act requirements.
(RT XXIX, 71:11-71:22.)
The GBUAPCD is currently in the process
of developing a SIP to bring the Mono Basin into
compliance with the Federal Clean Air Act. (GBUAPCD A, p.
1.) Mr. Ono testified that the SIP being developed
by his agency must provide reasonable assurance that the
standard would be met with the strategy that is included
in the plan. (RT XXIX, 30:1-30:5.)
Air Quality Modeling: In 1991, the
GBAPCD contracted with TRC Environmental Corporation
(TRC) to perform an air quality model evaluation to
assess dispersion modeling techniques for prediction of
PM-10 emissions in the Mono Basin. (GBUAPCD 3,
p. 1.) TRC evaluated the Industrial Source Complex
Short Term (ISCST) model and the Fugitive Dust Model
(FDM). The results of the evaluation were that the FDM
outperformed the ISCST overall and was found to be
technically superior for the prediction of PM-10
concentrations downwind of eroding source areas. In most
instances, however, the predictions of the two models
were similar. (GBUAPCD 3, p. 18; RT XXIX, 34:5-34:25.)
Under GBUAPCD direction, TRC used the Industrial Source
Complex-2 model (ISC-2), which was the U.S. EPA approved
dispersion model, to model PM-10 emissions. The ISC-2
model is routinely used for regulatory purposes. (GBUAPCD
A, II, p. 5) A Mono Lake Air Quality Modeling Study was
conducted to assess the impacts of windblown PM-10
emissions from the Mono Lake playa at different levels of
the lake. (GBUAPCD 10, p. 1.)
As part of their work on the Draft EIR,
Jones and Stokes Associates also evaluated air quality
impacts in the Mono Basin using a computer model as the
most practical method for developing quantitative air
quality assessments of future conditions. Jones and
Stokes Associates selected the Fugitive Dust Model (FDM).
Modeling procedures and results are presented in Mono
Basin EIR Auxiliary Report No. 28. (SWRCB 13z.)
Based on the investigations done by the
GBUAPCD and Jones and Stokes Associates, Mr. Ono
testified that an average Mono Lake elevation of 6,392
feet would provide an appropriate level of protection of
air quality. Mr. Ono also testified that he believes the
6,390 feet alternative identified in the Draft EIR, will
provide the necessary level of assurance to protect air
quality. (RT XXIX, 26:2-26:13.) The 6,390 alternative had
a projected median lake elevation of 6,391.6 feet. Mr.
Ono stated that the lake elevation alternatives 6,383.5
feet and lower (as identified in the Draft EIR) would not
satisfy the NAAQS for PM-10 and would not bring the Mono
Basin into attainment. (RT XXIX, 26:21-26:25.)
Mr. John Pinsonnault, an air quality
consultant to LADWP, acknowledged that during some
windstorms there will be exceedence of the Federal
standards at Simis Ranch and Warm Springs, as well as
other areas to the north and northeast of the lake. (RT
XII, 257:2-257:10.) Mr. Pinsonnault also testified that
the GBUAPCD monitoring data provide an excellent picture
of the air quality at the suggested lake elevations of
the LADWP plan. (RT XII, 257:14-257:20.) Mr. Pinsonnault
discussed his general concern with the models used by
GBUAPCD and JSA (RT XII, 258:1-261:25), but acknowledged
that use of models is necessary to estimate
concentrations of dust that could exist under certain
conditions. (RT XII, 257:21-257:25.) Mr. Pinsonnault
provided no data or studies to refute the findings of the
GBUAPCD or the Draft EIR.
Mr. Pinsonnault also proposed a theory
that as the lake elevation rises there could be increases
in the ground water level that could cause even greater
quantities of efflorescent salt crust to form at
elevations that at the present time do not have salt
crust. (RT XII, 264:23-265:7.) Although he was a member
of the Technical Advisory Group on air quality issues and
modeling for the Draft EIR, Mr. Pinsonnault testified
that he had not provided the EIR contractor with any data
or examples from the literature relating to issues he
raised at the hearing. (RT XXIII, 21:7-21:13 and
22:16-22:19.) Mr. Ono testified that there was no
foundation or data to support Mr. Pinsonnault's theory
about increased efflorescent salt problems at higher
water levels. (RT XXIX, 112:2-112:9.)
Other Potential Air Quality Mitigation
Measures: GBUAPCD Exhibit 23 is a memo dated
July 8, 1993 titled "Potential Mitigations For Mono
Lake And Their Engineering Implications." The memo
evaluates various alternatives to reduce or eliminate
emission source areas found on the relicted playa at Mono
Lake. The options evaluated were vegetation plantings,
sand fences, volcanic cinders or other coverings, and
chemical applications.
Dr. David P. Groeneveld, a plant
ecologist and principal investigator for testing
vegetation establishment on the saline Owens Drylake
playa, conducted several investigations at Mono Lake for
the GBUAPCD including a study titled, "Mono
Lakeshore Environments: Vegetation Establishment to
Control Airborne Dust." The conclusions of Dr.
Groeneveld's vegetation study were:
1. Zones of poor or absent vegetation
establishment on the eastern shore are constrained by
poor ground water quality and quantity. Without
artificial leaching, there will be no way to establish a
vegetation cover that is meaningful for dust suppression
on these zones;
2. Where vegetation is becoming
established naturally due to proximity to seepage zones
and springs (e.g., Simon Springs), artificial planting is
not a viable means of accelerating the process; and
3. Artificial plant establishment was
successful in an extended fetch zone to the east of Simon
Springs and has the potential to significantly reduce
blowing dust in this limited area. This zone lies above
the 6,393 foot contour. (GBUAPCD 26, pp. 1-2.)
Another study by Dr. Groeneveld,
"Seeps and Springs Around Mono Lake That Influence
Plant Establishment and Growth," reports that zones
which lacked vegetation establishment around the lake
(particularly the northeast area) coincided with waters
of low calcium content, high salinity and potentially
phytotoxic concentrations of boron and arsenic. (GBUAPCD
27, Abstract.) Dr. Groeneveld testified that, without
extensive irrigation using pumped freshwater to leach
those unvegetated saline zones, there would be no way to
enhance vegetation growth to reduce blowing dust. He
believes that condition will probably last tens to
hundreds of years. (RT XXIX, 41:3-41:7.) There was no
evidence provided as to the potential impact to ground
water resources of such an intensive irrigation program.
Mr. Theodore Schade, GBUAPCD Project
Manager for fugitive dust mitigation studies at Owens and
Mono Lake, testified that the GBUAPCD has tested a number
of fugitive dust mitigation measures at Owens Lake. The
measures tested at Owens Lake included sprinkler
irrigation, gravel blankets, artificial sand dunes and
chemical sprays. With the exception of the gravel
blanket, none of the measures reduced fugitive dust
levels enough to be considered successful and appropriate
for large scale implementation. (RT XXIX, 42:1-42:25.)
GBUAPCD Exhibit 23 addresses the quantity
of material that would be needed to implement a volcanic
cinder or gravel cover program on the Mono Lake playa.
(GBUAPCD 23, pp. 1-2.) The area between lake elevation
6,383.5 feet and 6,390 feet encompasses a noncontinuous
strip approximately 75,000 feet long between 675 and
2,000 feet wide, covering approximately 1,600 acres or
2.5 square miles. An estimated six inches of material
(1.3 million cubic yards) would have to be laid over the
mitigation area. This equates to approximately 162,000
dump truck loads (200 per day for three years) which
would be required to move the material to the site.
Mr. Schade testified that if a successful
engineering mitigation measure were identified, there
would need to be a significant amount of land disturbance
in the construction of the supporting infrastructure.
This infrastructure would likely include new roads,
pipelines, wells, powerlines, fences, sand fences and
barrow sites. The GBUAPCD has not specifically identified
any engineering measures that have a reasonable chance of
succeeding at Mono Lake. (RT XXIX, 44:2-44:18.)
6.4.5 Compliance with the Mono Basin
National Forest Scenic Area Comprehensive Management Plan
(CMP)
Section 304 of the 1984 California Wilderness Act (PL
98-425) established the Mono Basin National Forest Scenic
Area (Scenic Area). The Act required preparation of the
Comprehensive Management Plan for the Scenic Area which
was approved on March 16, 1990. (USFS 2, p. 1; RT
XXVIII, 15:1-25:4.) The plan recommends a lake elevation
range of 6,377 feet to 6,390 feet with management near
the midpoint of 6,383.5 feet. The plan is intended to
provide management direction for a 10 to 15 year period,
but recognizes there may be a need for modification based
on new information. (RT XXVIII, 15:8-25:25.) Forest
Supervisor Dennis Martin testified that the management
direction in the CMP needs to be reevaluated due to
reclassification of the Mono Basin as a nonattainment
area pursuant to the Clean Air Act. (RT XXVIII,
16:5-16:15.) Mr. Martin further testified that the USFS
was not aware of any proven or feasible methods of
physical mitigation that could be applied to the relicted
lands that would be consistent with the intent of the
federal legislation which is to preserve the natural
scenic beauty of the area. The USFS recommended that the
SWRCB should adopt the 6,390 feet alternative to bring
the Mono Basin into compliance with the Clean Air Act.
(RT XXVIII, 17:9-17:19.)
6.4.6 Conclusions Regarding Mono Basin
Air QualityThe
evidence establishes that the Mono Basin is in violation
of the national ambient air quality standard for PM-10
that was established for protection of human health. The
major source areas of PM-10 emissions are relicted
lakebed sediments encrusted with efflorescent salts. Most
of the major source areas were exposed due to the
declining water level in Mono Lake caused by LADWP's
diversion of water from the tributary streams. The only
feasible method of reducing the PM-10 emissions
sufficiently to come into compliance with the national
ambient air quality standards is to increase the water
elevation of Mono Lake and submerge much of the exposed
emission source area. The SWRCB recognizes that there is
a degree of uncertainty inherent in predicting future air
quality conditions based on the type of computer modeling
results presented at the hearing. Nonetheless, the
computer modeling results presented are the best evidence
currently available of what is needed to come into
compliance with applicable air quality standards.
Increasing the water elevation of Mono Lake to an average
level of 6,392 feet would provide a reasonable assurance
of establishing compliance with the national ambient air
quality standard for PM-10. Improving air quality at Mono
Lake by reducing the severity of periodic dust storms in
the Mono Basin would also protect the views and scenic
resources for which the Mono Basin is widely known.
6.5 Visual and Recreational Resources
Visual Characteristics of the Mono Basin
Historical Overview: Many early visitors to the Mono
Basin have described their impressions of the lake and
the landscape. (SWRCB 13x, pp. 3-5; SWRCB 7, Vol. 2, pp.
3I-1 to 3I-6.) John Muir described the Mono Basin as
"A country of wonderful contrasts, hot deserts
bordered by snow-laden mountains, cinders and ashes
scattered on glacier-polished pavement, frost and fire
working together in the making of beauty." (SWRCB
13x, pp. 2-3.) In contrast, Mark Twain wrote in Roughing
It: "Mono Lake lies in a lifeless, treeless,
hideous desert 8,000 feet above the level of the sea and
is guarded by mountains 2,000 feet higher whose summits
are always clothed in clouds. This solemn, silent
sailless lake, this lonely tenant of the loneliest spot
on earth is little graced with the picturesque." (RT
XVII, 164:17-165:12.) Mr. Twain went on to comment on the
tufa structures at Mono Lake as follows: "speaking
of the peculiarities of Mono Lake, I ought to have
mentioned that at intervals all around the shore, stand
picturesque turret looking masses and clusters of a
whitish, coarse grained rock that resembles inferior
mortar dried hard." (RT XVII, 184:7-187:24.) Despite
these contrasting descriptions, the increasing numbers of
visitors to the Mono Basin, and the many eloquent
statements presented during the policy statement
sessions, establish that the Mono Basin is a valuable
visual and recreational resource.
Prior to the export of water from the
Mono Basin beginning in 1941, natural variations in the
surface elevation of Mono Lake in historic times ranged
from a low of approximately 6,404 feet in 1862 to an
historic high of 6,428 feet in 1919. In 1941, the lake
level was at 6,417 feet. (SWRCB 13x, p. 4.)
Comprehensive descriptions of the visual
elements of the Mono Basin are found in the Draft EIR,
Auxiliary Report No. 24 to the Draft EIR and USFS Exhibit
1. (SWRCB 7, Vol. 2, Chapter I, pp. 3I-8 thru 3I-24;
SWRCB 13x, pp.8-18; and USFS 1, pp. 85-98.) The Mono
Basin has been described as a major scenic attraction in
the Eastern Sierra with considerable visual diversity due
to surrounding peaks such as Mt. Dana, Mt. Gibbs, and Lee
Vining Peak; glaciated valleys and morraines; dominating
volcanic features; Mono Lake and its islands, tufa
structures, playa, and wetlands; and the tributary
streams which feed the lake. (SWRCB 13x, pp. 10-11.)
The many birds and local concentrations of alkali flies
also are visual elements of the landscape. (NAS&MLC
36 and 41; SWRCB 13x, pp. 27-28.)
Mono Lake Tufa State Reserve: The
State established the Mono Lake Tufa State Reserve on
January 1, 1982. The reserve consists of the state owned
portion of the relicted lands and the Mono Lake bed lying
at or below elevation 6,417 feet. The legislation
establishing the reserve recognized that the tufa and
associated sand structures at Mono Lake are a valuable
geologic and scientific resource which should be
protected for the enjoyment and education of the public.
(Public Resources Code Section 5046.) These lands are
managed primarily for the protection of tufa and
associated sand structures and providing for their
interpretation. (RT XXV, 142:15-142:21.) Public Resources
Code Section 5019.65 provides in relevant part:
"The purpose of a State Reserve
is to preserve the native ecological associations, unique
fauna and flora characteristics, geological features, and
scenic qualities in a condition of undisturbed integrity.
Resource manipulations should be restricted to the
minimum required to negate the deleterious influence of
man."
Public Resources Code Section 5049
provides that natural or artificially caused accretion or
reliction of the waters of Mono Lake shall not be deemed
contrary to the purposes of the statute which established
the reserve. The California Department of Parks and
Recreation (DPR) is responsible for managing the Mono
Lake Tufa State Reserve.
Mono Basin National Forest Scenic Area:
The Mono Basin National Forest Scenic Area (Scenic Area)
was established in 1984. The Scenic Area includes some
76,703 acres of land and 41,600 acres of Mono Lake within
the Inyo National Forest. The legislative direction and
overall goal of the Scenic Area is to protect its
geologic, cultural, scenic, and other natural resources,
while allowing recreational, scientific, and other
activities consistent with that goal. (USFS 2, p. 16.)
After completion and public review of the Final
Environmental Impact Statement (EIS) and Comprehensive
Mangement Plan (CMP) for the Scenic Area, the Forest
Service adopted a management alternative for the Scenic
Area which emphasizes ecological, interpretive and visual
values.
Effects of LADWP Diversions on Visual
Resources: The effects of LADWP water diversions on
various resources have been addressed in detail in
previous sections of this decision. In general terms,
LADWP diversions have impacted visual resources as
described below.
1. Lake surface and shoreline:
Mono Lake is the single most important feature affecting
the recreational and visual resources of the Scenic Area.
(SWRCB 13x, p. 14.) The lake attracts the public and
provides for the many recreation and interpretive
opportunities within the Scenic Area. (RT XXV,
161:16-161:20.) Recreation user surveys at Mono Lake in
1992 reported that the most common visitor responses were
they had come to "see what the lake is like" or
for "sightseeing." (SWRCB 7, Appendix W, p.
W-4.)
The USFS used the Visual Resource
Management System (VRMS) to inventory and describe the
scenic landscapes, the landscape variety, key viewing
points, viewing zones, and the sensitivity of the
landscape to modification. The USFS found that the scenic
quality of the Scenic Area for most visitors is related
to the broad views and landscapes of the entire Mono
Basin that are visible from key view points. The most
important single feature of all of the views is Mono
Lake. The most important single element in those views is
water. Since the primary viewing context is of the whole
basin, it takes changes and variations to the landscape
that are broad in scope to create changes that would
impair those views. (USFS A-4, pp. 4-5.) When diversions
began, the lake surface covered approximately 86 square
miles. By 1989, the coverage was reduced to about 66
square miles. (SWRCB 7, Vol. 2, p. 3I-10.)
2. Islands: The two major islands
(Negit and Paoha) in Mono Lake are considered to be
visually positive elements, especially when perceived to
be true islands surrounded on all sides by water. (SWRCB
13x, p. 20.) Each island has clusters of smaller islets
nearby which change in number and size depending upon the
elevation of the lake. Some Negit islets existed prior to
diversions by LADWP. The Paoha islets emerged from Mono
Lake as it regressed below 6,395 feet in 1961. Negit
Island becomes landbridged to the mainland at a lake
elevation of 6,375 feet. (SWRCB 13v, p. 6.) In
recommending that Negit Island should remain an island,
State Park Ranger David Carle relied in part upon its
improved value as a visual resource when it is not
connected to the lakeshore. (DPR 4, p. 4.)
3. Playa: As the surface elevation
of Mono Lake fell, increasingly greater areas of former
lakebed have become exposed "playa" forming a
distinctive white area along the southern, northern and
eastern shores, which can be visually dominant in
elevated views and photographs. (SWRCB 13x, p. 13;
GBUAPC 14; and NAS&MLC 142.) The playa is almost a
mile wide in places. It consists of a relatively flat
surface encrusted with a salt efflorescence and sparsely
covered in some areas with vegetation. The air quality
impacts of dust storms caused by strong winds across the
exposed playa have been discussed previously. The dust
storms also reduce regional visibility and clarity of
scenic views. (SWRCB 13x, p. 30, and Figure 17; USFS 3,
video of dust storms.)
4. Tufa: Although tufa is found in
other alkaline bodies of water, the variety and quantity
of Mono Lake's towers are unique and distinctive. (SWRCB
7, Vol. 2, pp. 3I-11 and 3I-12.) Lithoid tufa is formed
when upwellings from calcium-bearing freshwater springs
in the lake bottom chemically mix with the alkaline
carbonate-rich waters of the lake. The calcium and
carbonates bond, precipitating out as a form of limestone
(calcite). The tufa forming process occurs only under the
water surface. Auxiliary Report No. 9 to the Draft EIR
describes the process of tufa formation in detail. (SWRCB
13i, pp. 3-5.)
Tufa deposits occur as pinnacles, domes,
and spires collectively called "lithoid tufa
towers." (SWRCB 3, Figure 5.8, p. 171.)
Delicately cemented lakebed sands form another kind of
tufa structure known as "sand tufa."
(SWRCB 13i, p. 1.) Lithoid tufa formations
occur at elevations varying from 6,368 feet to 6,432
feet. Sand tufa formations occur at elevations between
6,380 feet and 6,432 feet. (SWRCB 3, Figure 5.9, p. 172.)
While tufa formations are scattered throughout the Mono
Basin, there are six main "groves" of lithoid
tufa: South Tufa, Lee Vining Tufa Area, County Park (aka
Dechambeau Grove), Wilson Grove, Old Marina, and Simons
Springs. (SWRCB 7, Vol. 2, Figure 3I-9.)
Visible tufa existed in the prediversion
period as evidenced by Mark Twain's observation mentioned
above and the Israel Russell photographs of the Wilson
Grove (ca. 1883). (NAS&MLC 143 and 144.) Contrary to
the generally adverse visual consequences of a declining
Mono Lake, the declining water level has made large areas
of tufa formations accessible to public view. The
different lake elevations supported by various parties
will have varying degrees of impact on accessibility of
tufa to public view at various locations.
6.5.2 Recreation in the Mono Basin
Mono Lake was a popular recreation spot during the 1920s
and 1930s, and tourism was one of the Basin's most
important economic resources. (SC-A, p.1.) A 1938 Mono
County sportsman's map titled "Mono County Greets
You-Fisherman's Paradise" identifies lodges, camps,
lakes, streams, and local businesses of interest to
visitors. (CT 5-C.) In 1929, Venita McPherson promoted
and staged the first "Mark Twain Day" at the
Mono Inn to commemorate the humorist's stay in Mono
County in the 1860s. (SC-A, p. 2.) Mark Twain Day became
an annual event until the start of World War II. The
holiday featured power boat races, swimming events, horse
swimming races and a bathing-beauty contest. (SWRCB 7,
Vol. 2, p. 3J-2; SC 4 and 5.) During the 1930s, there
were boat tours of Mono Lake in which tourists were taken
to view the gulls on Negit Island and to swim in the hot
springs on Paoha Island. (SC 2 and 3.) By 1940, the June
Lake Loop had developed into a major outdoor recreation
area for summer and winter activities. (SWRCB 7, Vol. 2,
p. 3J-3.)
Today, recreation is the most significant
use of the Inyo National Forest totaling eight million
recreation visitor days in 1989. (SWRCB 7, Vol. 2, p.
3J-6.) Recreational demand is projected to increase at
approximately two percent per year for the next 50 years.
The USFS expects that visitations to the Mono Basin
National Forest Scenic Area will increase at a somewhat
faster rate until the year 2000. (USFS 1, p. 129.)
Visitors to the Scenic Area come from throughout the
world. (SLC&DPR 4a and 4b.) In 1986, 64
percent of all visitors came from California,
approximately 19 percent came from other states, and the
remainder came from other countries. (USFS 1, p. 129.)
Interpretive facilities exist at South Tufa, Old Marina,
Black Point, Navy Beach, County Park, Panum Crater and
the Scenic Area Visitors Center. Ranger David Carle
estimated that the Mono Lake Tufa State Reserve would be
visited by approximately 250,000 visitors in 1993.
(SLC&DPR 4, p. 15.)
As more people become aware of the
recovery of the lower reaches of Rush Creek and Lee
Vining Creek, recreation in those areas is expected to
increase. (SWRCB 7, Vol. 2, p. 3J-11.) The upper reaches
of Rush and Lee Vining Creeks are stocked by DFG with
catchable-sized trout. Other recreational activities
include camping, hiking, wildlife observation, and
photography.
The June Lake Loop supports year-round
recreation with most activity at the lakes occurring
during the summer. June Lake, Gull Lake, and Silver Lake
feature campgrounds which received a total of
approximately 42,000 visitor nights in 1991. (SWRCB 7,
Vol. 2, p. 3J-12 and Figure 3J-1.) Grant Lake features a
marina with a 70-unit campground, store, boat ramp,
moorage and boat rentals. The spillway elevation at Grant
Lake is 7,130 feet. When the water elevation drops below
7,111 feet (lake volume of approximately 21,000
acre-feet), the boat ramps at the lake are unuseable. Grant
Lake recreation use varies with lake level. Since 1986,
Grant Lake has averaged 48,000 visitor days, with fishing
as the most popular activity. Approximately 20 percent of
Grant Lake use typically occurs in April and May; 60
percent occurs in June, July and August, with 20 percent
in September and October. (SWRCB 7, Vol. 2, pp. 3J-9 to
3J-10.)
6.5.3 Effects of Different Lake Levels
on Visual Resources
Several lake level alternatives were evaluated in the
Draft EIR and addressed at the water right hearing. Each
of the alternatives affects visual resources and existing
or potential recreational opportunities in the Mono
Basin. Ms. Nancy Upham of the Inyo National Forest
testified on public expectations for management of the
Scenic Area. Based on her experience as a public affairs
official and former manager of the Scenic Area, Ms. Upham
believes that the public values wide open spaces, with
very little development or signs of human intrusion,
where people have opportunities to explore and learn
about the environment they are experiencing. The public
also has a fascination with tufa and likes to see birds
and wildlife which represent proof that the ecosystem is
healthy and thriving. (USFS A-7, p. 3.)
USFS Landscape Architect Edward Rickford
testified that the dewatering of the streams from which
LADWP diverts water and the lowering of the lake level
resulted in broad scale effects on visual resources in
the Mono Basin. (RT XXV, 163:2-164:8.) The rewatering of
the streams and restoration of the riparian corridors has
been addressed previously. Mr. Rickford testified that if
the lake rises from its current elevation (approximately
6,375 feet) up to approximately 6,390 feet, the focus of
interpretation, sightseeing and recreational activities
and use patterns around the lake are not expected to
change. However, above the 6,390 feet elevation, the
South Tufa area begins to lose its recreational carrying
capacity as the grove becomes inundated at higher levels.
(RT XXV, 161:24-162:8.)
Mr. Rickford testified that, from all key
view points, the landscape view will be greatly enhanced
by lake levels between the 6,383.5 feet alternative and
the 6,390 feet alternative. Raising the lake level to the
6,383.5 feet alternative or above will reduce the exposed
white alkali flats to where they are no longer a
significant adverse visual impact. Once the lake reaches
6,390 feet, the water will essentially meet existing
vegetation lines and the lake will appear as full and in
a natural appearing state from all view points.
(NAS&MLC 30 and 31, photographs.) Photographs
submitted by NAS&MLC depict the lake from several
view points at elevations ranging from 6,389 feet to
6,394 feet. (NAS&MLC 18, 22, and 29, photographs.)
From these photographs, Negit Island appears as an island
and the lake appears full.
6.5.4 Effects of Different Lake Levels
on Recreation and Tufa
Boating
and Swimming: Today almost all boating at Mono Lake
is limited to canoes and kayaks. Most boaters launch from
the Navy Beach parking area. DPR staff testified that if
the lake were to rise above 6,390 feet, the boat
launching ramps at Old Marina will be useable again.
(SLC&DPR 4, p. 13.) USFS staff testified that if the
lake rises, Old Marina would become a much more popular
access point to the lake. (USFS A-4, p. 3.) At 6,390 feet
or higher, boating access and swimming opportunities
could improve significantly. (RT XXV, 162:19-162:21.)
Lithoid Tufa: Lithoid tufa
formations (generally referred to simply as
"tufa") are one of the greatest scenic
attractions that bring visitors to Mono Lake. Visitation
to the Mono Lake Tufa State Reserve was expected to be
250,000 visitors in 1993. (RT XXV, 143:6-143:8.) Mr.
Rickford testified that tufa are visually enhanced when
water based. (RT XXV, 168:16-168:17.) Most of the
currently visible portions of the major groves of tufa
are land based and have been exposed by the receding
lake.
A visual preference survey was conducted
for the Draft EIR. Mono Lake visitors were shown a series
of photographs, each focusing on one of the landscape
elements (e.g., birds, water based tufa, land based tufa,
playa or sand tufa). They were asked to rate the
importance of the element to overall scenic quality.
Water based tufa attained the highest preference rating
and birds were second. Viewers had a higher visual
preference for water based tufa than for land based tufa.
(NAS&MLC 32 and 33, Photographs.) Sand tufa had a
higher visual preference than land based tufa but less
than water based tufa. (SWRCB 7, Appendix V, Table V-4.)
The SWRCB's evaluation of the relation
between tufa resources and lake level is based primarily
on the testimony of Dr. Scott Stine (RT XXV), David
Carle (SLC&DPR 4 and RT XXV), and Edward Rickford
(USFS A-4 and RT XXV), and from the Draft EIR (SWRCB 7,
Vol. 2, Chapter 3I), Auxiliary Reports to the Draft EIR
(SWRCB 13x and 13i), and a number of photographs in the
record. (SLC&DPR 4c, 4d, 4e and 4f; and NAS&MLC
23 through 28 and 30 through 35.) The six major tufa
sites are addressed below.
Simons Springs: This tufa group is
on the southeast side of the lake, 5 miles east of South
Tufa. The tufa is widely scattered and contains
relatively few towers. All structures are land based with
base elevations ranging from a low of 6,380 feet to a
high of 6,430 feet. Access is by hiking or along sandy
jeep trails. The remote location of this site makes heavy
use very unlikely. (SWRCB 13x, p. 23 and Table 1.)
Wilson Grove: This site, located
east of County Park, has towers that would remain exposed
above 6,400 feet as evidenced by the previously cited
photographs taken by I. C. Russel. (NAS&MLC 143, 144,
25, and 26.) At the current lake elevation, most of the
tufa are land based. There are about 100 tufa towers with
bases that lie at elevations between 6,375 feet and 6,410
feet. (RT XXV, 127:3-127:6; SWRCB 7, Vol. 2, Figure 3I-7;
and SLC&DPR 4h.) At a lake level of 6,377 feet,
approximately ten percent of the towers would be water
based; at 6,383.5 feet and 6,390 feet, approximately 30
percent of the towers would be water based. (RT XXV,
127:21-128:6.) At 6,407.1 feet, 20 percent would be
submerged and approximately 30 percent would be submerged
at a lake level of 6,410 feet. (SWRCB 13i, Table 2.) This
site (like most of the tufa areas other than South Tufa)
is characterized by a wet marsh which makes it difficult
to explore. (SLC&DPR 4, p. 9; and NAS&MLC 27
and 28, photographs.)
County Park/Danburg Beach: This
grove also has about 100 towers distributed from
approximately 6,375 feet to above 6,410 feet. At 6,383.5
feet, 20 percent of the towers would be water based and
80 percent are land based. Most of the tufa would be
water based and visible at a lake level of 6,390 feet.
(RT XXV, 129:20-130:18.) At 6,407 feet, 90 percent of the
tufa would be inundated. (SWRCB 13i, Table 2.) The County
Park formations are not subject to toppling. Because the
area is so wet, access is limited to a boardwalk trail
unless visitors are willing to walk through the marsh.
Access to the site is restricted at the east end by
private roads and residences. (SLC&DPR 4, p. 9.) The
County Park tufa group is more rounded or dome-like than
those found at the Lee Vining group or South Tufa. (SWRCB
13x, p. 23 and Figure 12.)
Old Marina: The Old Marina site is
heavily visited because of its proximity to U.S. Highway
395. The size and visual impact of the site do not
compare with the other tufa areas. There are a few tall
structures, but most of the tufa is in the form of craggy
boulders. (SWRCB 13x, p. 23 and Figure 12; and
NAS&MLC 31, photograph.) The shoreline is muddy at
the current lake elevation, making access difficult. A
boardwalk constructed by DPR for walking and wheelchair
access provides only partial access at the current lake
level. (SLC&DPR 4, p. 9.)
Lee Vining Tufa: Lee Vining Tufa
is the largest tufa area at Mono Lake. (SLC&DPR 4f
and 4g.) The area has both water based and land based
tufa. It is similar to the South Tufa site, although
wetter and more densely vegetated. There is limited
access by foot. (SLC&DPR 4, pp. 8-9.) Lee Vining Tufa
towers extend up the shoreline to about 6,407 feet. At
6,377 feet, approximately 10 percent of the tufa would be
water based and the remainder would be land based. At
6,383.5 feet, approximately 20 percent would be water
based and 80 percent land based. At 6,390 feet,
approximately 20 percent of the towers would be submerged
and the remaining tufa would be split between water based
and land based. (RT XXV, 131:10-131:23.) At 6,407 feet,
95 percent of the grove would be inundated. Total
submergence would occur at 6,410.3 feet. (SWRCB 13i,
Table 2.)
South Tufa: The South Tufa area is
the main visitor site at Mono Lake with 137,000 visitors
by fall of 1993 and 173,225 visits in 1992. (RT XXV,
151:14-151:16; USFS A-4, p. 7; and SLC&DPR 4c, 4d and
4e, photographs.) Recreation use is expected to increase.
(USFS A-4, p. 7.) South Tufa is different from the other
tufa groves in several respects:
1. In contrast to the much older tufa at
other locations, the South Tufa area is believed to be
less than 100 years old. As a consequence the tufa
structures are more shallowly rooted in the sediment. (RT
XXV, 132:3-132:10.)
2. At South Tufa, a rise or fall in lake
level can undercut the sediment of the shallowly rooted
small towers (solitary small towers less than four feet
in diameter) causing them to topple. The large
agglomerations of tufa called bulwarks and the large
domes tufa would not be expected to topple. (RT XXV,
132:11-133:1-25). Toppling is not a problem at other
groves.
3. It is possible to walk to the
shoreline without encountering mud or marsh. Birds, flies
and shrimp are accessible at South Tufa. The area can
accomodate up to 200 people at a time and up to 1,200
people per day. The large carrying capacity is partially
because of the acreage of the tufa area combined with
relative ease of access. (RT XXV, 151:14-152:15.) Daily
traffic can easily reach 200 to 300 vehicles. (USFS A-4,
p. 7.)
4. Because of the size of the tufa grove
and the existing loop pathways, the South Tufa area
allows people to get out of sight of each other. (RT XXV,
153:24-154:2.) The USFS completed a topographic survey of
the South Tufa area in May of 1993 to be used in the
redesign and rehabilitation of the recreation facilities.
(USFS A-4, p. 9.) Maps that graphically display the
visible tufa, and existing and potential trail systems at
specific lake levels were presented as exhibits. (USFS
9-12.) Mr. Rickford testified as to the visual and
recreational characteristics of South Tufa as depicted by
the survey maps at different lake levels. Key points from
Mr. Rickford's assessment are summarized below.
1. Lake level of 6,377 feet:
Basically all of the tufa is land based. Most visitors
quickly walk by most of the grove to reach tufa in the
water-shore zone. Opportunities for viewing water based
tufa close to the South Tufa grove are quite limited at
6,377 feet. (USFS A-4, pp. 9-10; USFS 9.)
2. Lake level of 6,383.5 feet:
Approximately 18 acres of land based tufa are available
which will accommodate all levels of expected use and
provide a viable recreation and interpretive experience.
Density of use will increase requiring the trail to be
further defined from the existing conditions. Paved
trails and boardwalks become a possibility. The shoreline
is on average 300 feet closer to the parking area making
the grove more accessible for some. More of the tufa is
water based. There will be 18 to 20 islands of tufa that
will enhance the visual variety and quality of the views.
Very little of the tufa will be totally submerged. (USFS
A-4, pp. 10-11; and USFS 10.)
3. Lake level of 6,390 feet:
Approximately 9 acres and 35 to 40 percent of the tufa
stands will be land based. All of the rest of the tufa
will be water based or project into the lake. At the
6,390 feet alternative, visitors can still experience
tall tufa in dense stands and bulkwarks and a looptrail
system can be maintained. Approximately 25 to 30 tufa
islands will be visible 100 to 800 feet from shore.
Although many of the shorter towers will be submerged,
this does not create a noticeable visual impact. The
shoreline will be 500 to 800 feet closer to the parking
lot, thus making the water more accessible. Trails will
be further defined and visitors will not be free to roam
at will through the grove. This alternative will still
provide adequate carrying capacity for the expected use
and South Tufa will still function as the primary on-site
interpretive opportunity along the shoreline of Mono
Lake. (USFS A-4, pp. 11-12; USFS 11.)
4. Lake levels of 6,400 feet and 6,410
feet: At 6,400 feet, nearly all significant tufa
becomes water based and most of the major tufa islands
will be submerged. Approximately 10 percent of the tufa
will be visible as water based tufa. The land based
carrying capacity of the South Tufa site is eliminated
and opportunities to walk among the tufa are gone.
Launching of canoes and light boats may increase.
Interpretation oriented visitor use will probably decline
and will shift to other sites. At the 6,410 feet
elevation, all tufa will be essentially submerged thus
eliminating the major visual element and focus that
attracts visitors to the site. (USFS A-4, pp. 12-13; USFS
12.)
Mr. Rickford's testimony supports the
conclusion that a lake level in the range covered by the
6,390 alternative evaluated in the Draft EIR would
provide for a good recreation development base and
positive visitor experience. At substantially higher
water levels, use would have to be shifted to other
areas. (USFS A-4, p. 14.)
Mr. Carle testified that at lake levels
higher than 6,398 feet, all of the significantly tall
towers would be off shore, with many more submerged. At
elevations above 6,400 feet, the experience will be
significantly diminished. Due to remote locations or
surrounding marshland, it is unlikely that some tufa
areas will ever be heavily visited. Mr. Carle believes
that there needs to be a "major visitor site"
like South Tufa to accomodate large numbers of visitors.
(SLC&DPR 1-4, pp. 10-11.)
Sand Tufa: Sand tufa are
considered an important visual resource because of their
unique formations. (SWRCB 13x, p. 25; SWRCB 7, Vol. 2,
Figure 3I-13.) Sand tufa occur along the south shore of
Mono Lake most notably at Navy Beach. (SWRCB 13x, Figure
11.) Deposits occur over a wide range of elevations, from
6,435 feet through a band lying between 6,425 and 6,417
feet, and down to the better known formations at 6,380
feet to 6,390 feet. (NAS&MLC 1AF, p. 1.) Sand tufa
deposits at the higher elevations are not presently
exposed. Sand tufa are cemented lakebed sands that have
been exposed due to lake regression and wind erosion. The
cemented sands form delicate-looking and intricately
connected tubular structures when exposed that range in
height from several inches to over six feet. They also
can be seen in cross-section along the cliffs of wave-cut
terraces such as the terrace immediately below the Navy
Beach parking lot. (SWRCB 13i, p. 17.)
DPR staff and Dr. Stine surveyed the sand
tufa areas at Mono Lake. Their results indicate that, at
the higher water levels of the 6,383.5 alternative,
virtually all of the currently exposed sand tufa would be
undercut. The lake would have to remain below 6,384 feet
to protect all of the major sand tufa sites. (SLC&DPR
1-4, p. 12.) Mr. Carle stated that the Navy Beach sand
tufa are the most visited of the sand tufa sites, the
most accessible being in the exposed cliff face. (RT
XXVIA, 75:25-76:3.) Dr. Stine testified that major low
lying sand tufa will be undercut and lost even by lake
elevations proposed under the LADWP Management Plan. (RT
XXV, 137:12-137:25.) Mr. Carle testified that major tufa
sites would likely be undercut between elevations 6,384
and 6,392 feet, but that new exposures of sand tufa in
new incised cliff faces seem likely. (RT XXV,
154:23-155:3.) Dr. Stine expects, that in most cases, the
cliffs that would form as a result of a rise in lake
level would be exposing sand tufa similar to the one
cliff at Navy Beach. (RT XXV, 216:7-216:21.) Dr. Stine
testified that it was his opinion that more sand tufa
would be exposed in cliff faces than exists today,
although there would be less free-standing sand tufa at a
lake level of 6,390 to 6,400 feet. (RT XXVIA,
128:5-128:14.)
The DPR has closely monitored the sand
tufa for the last ten years by maintaining a photo
inventory. They have documented very few obvious visual
changes in that decade. Based upon review of the
condition of the sand tufa over a range of ages, however,
Dr. Stine concluded that a substantial reduction of sand
tufa occurs over a period of a half century. He considers
it likely that, independent of any change in lake
elevation, the tall, free-standing sand tufa deposits
between 6,380 and 6,390 feet will undergo pronounced
reduction and collapse over the next 50 years due to
weathering and erosion. (NAS&MLC 1AF, p. 1.)
Mr. Rickford testified that the loss of
the sand tufa is not considered a negative visual impact
because the scale of sand tufa does not show up in the
key viewpoints of the landscape. Sand tufa is visible
only to a person who is very close. (RT XXVIA,
36:2-36:25.)
6.5.5 Agency Recommendations
The U. S. Forest Service, the California Department of
Parks and Recreation and the State Lands Commission have
responsibilities for land management and recreation in
the immediate vicinity of Mono Lake. The USFS recognizes
that there are many different types of resources that
must be considered in their Comprehensive Management Plan
for the Mono Basin National Forest Scenic Area and that
no single lake elevation maximizes all of those
resources. (RT XXVIA, 84:3-84:14.) Based on review of all
the evidence provided, the USFS recommended adoption of
the 6,390 feet alternative described in the Draft EIR.
(RT XXV, 180:2-180:8.)
The California Department of Parks and
Recreation also recommended adoption of the 6,390 feet
alternative based on the conclusion that "it offers
the best balance among all the resources used which must
be considered, including the natural and geological
resources, recreation and visual elements, and air
quality concerns." (RT XXV, 144:23-145:3.)
The State Lands Commission is charged
with the administration of the public's interest in the
beds of navigable lakes and rivers, and the
identification and protection of environmentally
sensitive lands. (State v. Superior Court
(Lyon) (1981) 29 Cal.3d 210, cert. denied 454 U.S.
865; Public Resources Code Sections 6370 and 6378.) The
joint recommendation in the SLC&DPR closing brief is
that a lake level of at least 6,390 feet is necessary to
protect most of the public trust values of Mono Lake.
(SLC&DPR, Closing Brief pp. 4 and 5.) SLC&DPR
contend that "6,390 feet provides a stable lake
ecosystem with some benefit to the public trust values
while still allowing exports of water from the basin. It
is not a perfect solution, but it is a reasoned
one." (SLC&DPR, Closing Brief, p. 54.)
The state and federal land management
agencies in the Mono Basin all favor a water elevation
that would undercut and submerge most of the exposed sand
tufa structures near Mono Lake. In view of the large
public interest in viewing these unusual formations,
however, it would be appropriate for those agencies to
evaluate the feasibility of relocating one or more of the
sand tufa structures to a protected location such as the
Forest Service Mono Basin Visitor Center.
6.5.6 Conclusions Regarding Visual and
Recreational Resources
The
evidence discussed above establishes that the visual
scenery in the Mono Basin is one of the area's most
important assets. A lake level of approximately 6,390
feet would have a number of visually beneficial effects
including the following: (1) it would give the visual
appearance of a full lake; (2) it would submerge the
landbridge to Negit Island and restore Negit Island to
its former condition as a true island; (3) it would
increase the proportion of water based tufa; (4) it would
greatly reduce the area of dry, sparsely vegetated playa
surrounding Mono Lake; amd (5) it would reduce the
severity of dust storms which reduce visibility and
interfere with the wide open scenic views.
Fishing and other recreation on the lower
portions of the tributary streams to Mono Lake will be
benefitted by the restoration of flows and other measures
previously addressed in this decision. Recreation at
Grant Lake would benefit by maintaining the water
elevation at or above 7,111 feet from May 31 through
Labor Day when feasible while still maintaining instream
flow requirements for fish.
At Mono Lake, an increase in water level
to the 6,390 feet range would improve boating access and
reduce salinity which would make swimming more enjoyable.
The primary recreation at Mono Lake involves visits to
the unusual tufa formations. The South Tufa area is the
most heavily used interpretive and recreational site at
Mono Lake. Maintaining a lake level of approximately
6,390 feet would retain the accessibility of the South
Tufa area to visitors and would increase the proportion
of visually appealing water based tufa. Maintaining a
lake level of approximately 6,405 feet or higher, as
advocated by some parties, would submerge or totally
eliminate the functional use of the South Tufa area
except to those in boats. The other tufa sites are
generally smaller and located in wetter or marshy areas.
The evidence in the record does not establish that other
tufa areas would be able to fully absorb the shift in
recreational demand if the South Tufa area were
inaccessible.
6.6 Mono Lake Water Quality and
Designation as Outstanding National Resource Water
Mono Lake is a sink in a closed hydrologic system having
no natural outlet. Inflow from tributaries, ground water
and mineral springs contains dissolved salts which enter
the lake and slowly accumulate. Because the water quality
of the inflow to Mono Lake is very high, the increase in
salinity is so slow that the total mass of dissolved
salts in Mono Lake is considered a constant. (SWRCB 7,
pp. 3B-7 and 3B-8.) The salinity of water in the lake is
a function of the volume of water in the lake, which in
turn is reflected by the water elevation. (SWRCB 7,
p. 3B-7.)
In 1941, when the lake level was 6,417
feet, the estimated total dissolved solids (TDS) in Mono
Lake were 48 grams per liter (g/l), as compared to a TDS
of approximately 35 g/l for seawater. (SWRCB 7, pp. 3B-7
and 3B-8.) As the volume of water in the Mono Lake has
decreased through evaporation and reduced inflow, the TDS
of the lake has increased. (SWRCB 7, p. 3B-1.) At the
point of reference condition evaluated in the Draft EIR,
the water elevation of Mono Lake was 6,376.3 feet, and
the TDS was 90 g/l, or nearly 90 percent greater than the
prediversion condition and more than 2.5 times as salty
as seawater. (SWRCB 7, p. 3B-27.)
As discussed in Section 6.1, laboratory
experiments show a direct relationship between salinity
and production of the Mono Lake brine shrimp and the Mono
Lake alkali fly which serve as the main food source for
many migratory birds. At a lake level of approximately
6,390 feet, the salinity of Mono Lake would be
approximately 71 g/l. (SWRCB 7, Table A-1.) Previously
discussed testimony establishes that a salinity of 75 g/l
or less would maintain the aquatic productivity of the
brine shrimp and brine fly in good condition, but that a
substantially higher salinity would have negative
effects. (See Section 6.1.)
Water quality at Mono Lake is subject to
the federal antidegradation policy which was enacted
pursuant to the Clean Water Act. (40 CFR, § 131.12.) The
antidegradation policy establishes general narrative
water quality standards which apply where other water
quality standards do not address a particular pollutant.
The antidegradation policy establishes a three-part test
for determining when reductions in water quality may be
permitted.
The first tier of protection under the
antidegradation policy requires that "existing
instream water uses and the level of water quality
necessary to protect the existing uses shall be
maintained." (40 CFR § 131.12(a)(1).)
The second tier applies to situations
where water quality exceeds the level necessary to
support fish, shellfish, wildlife and recreation. In that
situation, the federal antidegradation policy requires
that existing water quality be maintained unless it finds
that:
"...allowing lower water quality
is necessary to accomodate important economic or social
development in the area in which the waters are located.
In allowing such degradation or lower water quality, the
State shall assure water quality adequate to protect
existing uses fully...." (40 CFR § 131.12(a)(2).)
Finally, the third tier provides that:
"Where high quality waters
constitute an outstanding National resource, such as
waters of National and State parks and wildlife refuges
and waters of exceptional recreational or ecological
significance, that water quality shall be maintained
and protected." (40 CFR § 131.12(a)(3),
emphasis added.)
In addition to waters of exceptionally
high water quality, Outstanding National Resource Waters
may also include:
"Water bodies which are
important, unique or sensitive ecologically, but whose
water quality as measured by traditional parameters
(dissolved oxygen, pH, etc.) may not be particularly high
or whose character cannot be adequately described by
these parameters." (48 Fed. Reg. 51402, Nov. 8,
1983.)
The federal antidegradation policy
applies to reductions in water quality which occurred or
threatened to occur after the policy was adopted. When
the antidegradation policy was adopted in November 1975,
the salinity of Mono Lake was approximately 85 g/l at a
lake level of 6,379.3 feet.
SWRCB Resolution No. 68-16 establishes
requirements similar to the federal antidegradation
policy. In all cases where the federal antidegradation
policy is applicable, SWRCB Resolution No. 68-16 requires
that, at a minimum, the three-part test established by
the federal antidegradation policy must be satisfied.
(SWRCB Order No. WQ 86-17 at pp. 17-18.)
Due to the evidence indicating an inverse
relationship between salinity and aquatic productivity of
the brine shrimp and brine fly (Section 6.1 above),
allowing water diversions resulting in a salinity higher
than 85 g/l would be contrary to the first tier of the
antidegradation policy and contrary to SWRCB Resolution
No. 68-16 because the productivity of the brine shrimp
and brine fly would decline as salinity increased.
Moreover, in view of the substantial
evidence in the record about the unique nature of the
Mono Basin ecosystem, the key role of Mono Lake in
providing habitat for many species of birds dependent
upon the brine shrimp and brine fly, and the tremendous
public interest in protection of Mono Basin wildlife, the
SWRCB finds that Mono Lake constitutes an Outstanding
National Resource Water having exceptional ecological
significance. As such, the water quality which existed in
November 1975 when the federal antidegradation regulation
was enacted must be maintained and protected. To maintain
the salinity of Mono Lake at 85 g/l or lower would
require that the water level of the lake be raised and
maintained at 6,379.3 feet or higher.
The SWRCB is aware that it may take a
number of years to reach the target lake level and that
the water elevation of Mono Lake can fluctuate
substantially in response to hydrologic changes. However,
LADWP's water right licenses should be amended to include
conditions which provide a reasonable assurance of
maintaining an average water elevation above 6,379.3 feet
in order to maintain the water quality which existed when
the antidegradation policy was established.
The federal antidegradation policy sets
requirements for when the water quality which existed in
November 1975, must be maintained. Water quality
objectives must, at a minimum, be consistent with the
federal antidegradation policy, but other considerations
may call for setting objectives which provide a higher
level of water quality. Water quality objectives must
also protect the beneficial uses designated for
protection, even if 1975 water quality was not adequate
to protect those uses. (40 C.F.R. § 131.11(a); Cal.
Water Code § 13241(a).)
The Water Quality Control Plan for the
South Lahontan Basin was adopted by the California
Regional Water Quality Control Board, Lahontan Region,
and approved by the SWRCB in 1975. The beneficial uses
for Mono Lake designated for protection by the plan
include saline water habitat, wildlife habitat, and water
contact recreation. The water quality objective for
salinity set by the 1975 plan is 76 g/l. The beneficial
use designations and water quality objectives set by the
1975 plan have been approved by U.S. EPA as the water
quality standards for Mono Lake. The water quality
objective of 76 g/l is considerably below the present
salinity of Mono Lake and would correspond to a lake
level of approximately 6,386 feet.
The reasonableness and public trust
doctrines provide the SWRCB with continuing authority to
reopen previous water allocation decisions to consider
impacts on water quality and enforce water quality
standards. (United States v. State Water
Resources Control Board (1986) 182 Cal.App.3d 82,
129-30, 149-51, [227 Cal.Rptr. 161, 187-88, 201-202].) As
discussed above, salinities substantially above 75 g/l
would have negative effects on the aquatic productivity
of the brine shrimp and brine fly. The adopted water
quality objective of 76 g/l is reasonably necessary to
protect the designated beneficial uses of Mono Lake.
Enforcement of the objective under the SWRCB's water
right authority is the only feasible means of attaining
that objective. Consistent with the reasonableness and
public trust doctrines, LADWP's water right licenses
should be amended to provide a reasonable assurance of
maintaining an average water elevation at or above 6,386
feet in order to comply with the water quality standards
for Mono Lake.
In reaching a decision on the criteria
governing water diversions under LADWP's licenses, the
SWRCB has considered the salinity standard for Mono Lake
established in the basin plan, the federal
antidegradation policy, and the antidegradation policy
established in SWRCB Resolution No. 68-16. The water
diversion criteria discussed in Section 6.8 of this
decision will result in reducing the salinity of Mono
Lake to a level consistent with those standards and
policies.
6.7 Conclusions Regarding Desired Lake
Level for Protection of Public Trust Resources
The instream flow requirements for restoration and
maintenance of fish in the four diverted streams are
discussed in Sections 5.0 through 5.5 above. Computer
modeling results using the LAAMP model (Version 3.31,
SWRCB 49) suggest that establishing the specified
instream flows (without any additional water that may be
needed to raise the water level of Mono Lake) would:
(1) cause the water level of Mono Lake to reach
6,390 feet in roughly 29 to 44 years depending on the
assumptions which are made regarding future hydrology;
and (2) result in total inflow to Mono Lake sufficient to
maintain an eventual lake level of approximately 6,388
feet to 6,390 feet for the 50-year period after a lake
level of 6,391 feet is reached, depending upon future
hydrology.
As discussed in Sections 6.4 through
6.4.6, the record indicates that compliance with federal
air quality standards will require an average water level
of approximately 6,392 feet in order to submerge a
sufficient portion of the playa to reduce the blowing of
PM-10 particles to within applicable limits. In addition,
the evidence discussed in Section 6.3.7, indicates that
restoration of all or nearly all of the waterfowl habitat
which has been lost since 1941 would require a lake level
over 6,405 feet. However, some waterfowl habitat would be
restored at 6,390 feet and there are opportunities for
restoration of additional waterfowl habitat through
various mitigation measures identified in the Draft EIR
and hearing record.
A lake level of 6,405 feet would not be
consistent with the objectives of preserving public
access to the most frequently visited tufa sites and
continuing to make tufa structures at Mono Lake widely
and conveniently accessible to public view. In addition,
restricting diversions by LADWP to the extent necessary
to reach and maintain a water level above 6,405 feet as
recommended by the NAS&MLC would result in even
greater restrictions upon the diversion and use of water
for municipal and power needs.
In determining the most appropriate water
level for protection of public trust resources at Mono
Lake, the SWRCB recognizes that there is no single lake
elevation that will maximize protection and accessibility
to all public trust resources. In addition, variations in
hydrology are such that there will continue to be
fluctuations in the water level of Mono Lake regardless
of what target lake level is selected.
Based on the evidence discussed in
previous sections, the SWRCB concludes that maintaining
an average water elevation sufficient to result in
compliance with federal air quality standards will also
provide appropriate protection to public trust resources
at Mono Lake. The record indicates that an average water
elevation of 6,392 feet would be consistent with
protection of a number of important public trust
resources including: air quality in the Mono Basin; water
quality in Mono Lake; the Mono Lake brine shrimp and
brine fly which provide food for migratory birds; secure,
long-term nesting habitat for California gulls and other
migratory birds; easily accessible recreational
opportunities for the large number of visitors to the
Mono Lake Tufa State Reserve; and the panoramic and
scenic views which attract many people to the Mono Basin.
6.8 Criteria for Regulating Water
Diversions in Order to Reach and Maintain Desired Lake
Level
Transition Period: To reach and maintain a water
elevation sufficient to protect the public trust
resources discussed above while allowing water diversions
to the City of Los Angeles under appropriate conditions,
LADWP's water right licenses should be amended to limit
diversions in the following respects until the water
level of Mono Lake reaches 6,391 feet:
1. No diversions of water unless fish
flow requirements are met: The minimum flows needed
to restore and maintain the pre-1941 fisheries to the
four affected streams are specified in Sections 5.0
through 5.4.4 above. Diversion of water under LADWP's
licenses should be allowed only when the required flows
for fishery protection are met. The licenses should also
require LADWP to release water for channel maintenance
and flushing purposes in accordance with previously
addressed requirements.
2. No diversions until a lake level of
6,377 feet is reached: No diversions of water should
be allowed under LADWP's water right licenses any time
that the water level in Mono Lake is below or is
projected to be below 6,377 feet during the runoff year
of April 1 through March 31.
3. Diversions allowed at lake levels
above 6,377 feet and below 6,380: If the water level
of Mono Lake is expected to remain at or above 6,377 feet
throughout the runoff year of April 1 through March 31
(based on the May 1 runoff projections and any subsequent
projections that LADWP makes), then LADWP would be
allowed to divert up to 4,500 acre-feet per year for the
purposes of use specified in its licenses.
4. Diversions allowed between lake
levels at or above 6,380 feet and below 6,391 feet:
At water levels in Mono Lake at or above 6,380 feet and
less than 6,391 feet, LADWP would be allowed to divert up
to 16,000 acre-feet per year under its licenses.
5. Reconsideration of water diversion
criteria if lake level does not reach 6,391 feet in 20
years: In the event that the water level of Mono Lake
has not reached 6,391 feet by September 28, 2014, the
SWRCB will hold a hearing to consider the condition of
Mono Lake and the surrounding area and will determine if
further revisions to the licenses are appropriate.
After Transition Period: Once a
lake level of 6,391 feet is reached, diversions under
LADWP's licenses should be allowed in accordance with the
following criteria:
1. No diversions allowed at lake
levels below 6,388 feet: Once the water level of Mono
Lake has reached an elevation of 6,391 feet, no
diversions would be allowed at any time the water level
falls below 6,388 feet.
2. Diversions allowed at lake levels
between 6,388 feet and 6,391 feet: Once a water level
of 6,391 feet has been reached, diversions by LADWP would
be limited to 10,000 acre-feet per year any time that the
water level is at or above 6,388 feet and below 6,391
feet, provided that fishery protection flows and channel
maintenance and flushing flow requirements are met.
3. Diversions allowed at lake levels
at or above 6,391 feet: At lake levels at or above
6,391 feet on April 1, LADWP may divert all available
water in excess of the amount needed to maintain the
required fishery protection flows and the channel
maintenance and flushing flows up to the amounts
otherwise authorized under LADWP's licenses.
For purposes of the water diversion
criteria specified above, the water level of Mono Lake
would be measured on April 1 of each year, and the
limitations on water diversions would apply for the one
year period of April 1 through March 31 of the succeeding
year.
The water diversion criteria specified
above are based on: (1) the legal requirement to
provide fishery protection flows; (2) the need to reach a
lake level that is consistent with protection of public
trust resources in the Mono Basin in a reasonable amount
of time; and (3) the constitutional mandate to maximize
the reasonable and beneficial use of water and avoid
unnecessary or unreasonable restrictions upon the water
diversions serving the municipal needs of Los Angeles.
The feasibility of the specified water diversion criteria
in view of the effects on Los Angeles' water and power
supply is discussed later in this decision.
Computer modeling using Version 3.31 of
the LAAMP model indicates that, assuming a repeat of 1940
through 1989 hydrology, the above criteria would result
in Mono Lake reaching an elevation of 6,390 feet in
approximately 28 years. The water level would be expected
to reach 6,392 feet in approximately two more years.
Using an assumed future hydrology based on a
"rolling average" of the hydrologic years 1940
through 1989 would result in reaching a lake level of
6,390 feet in approximately 18 years. Computer modeling
(using 1940 through 1989 hydrology) indicates that the
above diversion criteria would result in maintaining an
average lake level of approximately 6,392.6 feet during
the next fifty year period after an elevation of 6,391
feet is reached. The water level should remain above
6,390 feet approximately 90 percent of the time.
In projecting the expected effects of the
diversion criteria specified above on the future water
level in Mono Lake, the SWRCB is keenly aware of the
limitations of computer modeling hydrologic systems and
the probability that future hydrologic conditions may
differ significantly from historical conditions. If there
were a series of extremely wet years, for example, Mono
Lake could reach an elevation of 6,391 feet in much less
than 20 years. Similarly, an extended series of very dry
years could lengthen the period before 6,391 feet is
reached. Under the circumstances, there is limited value
in attempting to fine tune computer model projections of
inherently uncertain conditions many years in the future.
If future conditions vary substantially from the
conditions assumed in reaching this decision, the SWRCB
could adjust the water diversion criteria in an
appropriate manner under the exercise of its continuing
authority over water rights.
7.0 BENEFICIAL USES SERVED BY WATER
DIVERSIONS
Use of Mono Basin Water for Municipal Purposes
As discussed previously, the Court of Appeal decisions in
the Cal Trout cases establish that water needed to
protect fish in the four diverted streams is not
available for diversion by LADWP. In determining the
extent to which additional restrictions should be placed
on LADWP's water right licenses for protection of other
public trust resources, the SWRCB is compelled to
consider the feasibility of those restrictions in view of
the other beneficial uses made of the water diverted. The
primary beneficial use of water exported from the Mono
Basin is to serve the municipal needs of the City of Los
Angeles. Sections 7.1.1 through 7.1.4 address present
water use and water supplies for Los Angeles, the
expected water supply impacts of this decision, and the
expected impacts of this decision on the water quality in
Los Angeles.
7.1.1 Present Water Use and Water
Supplies for the City of Los Angeles
Water use in Los Angeles varies on a seasonal and
yearly basis in response to climatological conditions.
Demand is higher in summer and hot, dry years, and lower
in winter and during cooler, wetter years. Indoor water
use remains fairly constant and outdoor use accounts for
most of the variation. (SWRCB 7, p. 3l-4.) At the time
the Draft EIR was prepared, daily water use was about 179
gallons per person which is moderately low in comparision
to other cities in California and elsewhere in the
country. (SWRCB 7, p. 3L-4; LADWP 104 B, p. 162.)
Local ground water has provided a
relatively stable source of supply over the past 50
years. Water supplies from the Los Angeles Aqueduct and
the Metropolitan Water District of Southern California
(MWD) have been more variable. During dry years,
reductions in Los Angeles Aqueduct deliveries from the
Owens and Mono Basins have usually been replaced by water
from MWD. During wet years, LADWP generally has limited
purchases from MWD because historically that has been
LADWP's most expensive source of supply. (SWRCB 7, p.
3L-9.)
LADWP obtains an average of about 112
thousand acre-feet per year from local ground water
basins, with ground water consumption being highest
during drought years when other supplies are more
limited. (SWRCB 7, p. 3L-9.) The expansion of the Los
Angeles Aqueduct in 1970 allowed Los Angeles to export an
average of about 450 thousand acre-feet per year from the
Owens and Mono Basins, with the Owens Basin supplying
about four fifths of aqueduct deliveries. (SWRCB 7, p.
3L-9.) Since June of 1989, however, LADWP has been
prohibited from exporting any Mono Basin water, except
for about three thousand acre-feet used for a fishery
study on the upper Owens River. (NAS&MLC 5, p. 10;
LADWP 149, Table 3.)
Los Angeles also purchases water from
MWD, which presently serves 27 member agencies. From 1970
to 1990, LADWP purchased an average of 78.6 thousand
acre-feet per year from MWD, amounting to about 13
percent of its total supply. LADWP has purchased more
water from MWD during drought periods than in other
years. In fiscal 1989-1990, for example, much of the
State was in the fourth consecutive year of drought and
the previously mentioned preliminary injunction
prohibited water exports from the Mono Basin. As a
result, LADWP purchased approximately 385 thousand
acre-feet from MWD, or about 55 percent of its total
needs. LADWP has a current entitlement to about 26
percent of MWD water. (SWRCB 7, p. 3L-10.)
MWD receives water from the Colorado
River and the State Water Project. MWD's firm
apportionment of Colorado River water is about 550
thousand acre-feet per year. For several years, however,
MWD has been receiving approximately 1.2 million
acre-feet per year from the Colorado River, including
surplus water, unused California agricultutral water, and
unused water allocated to other states. (SWRCB 7, p.
3L-10; MWD 1, p. 8.)
The SWP transports water from the Delta
via the California Aqueduct to MWD. Under existing water
right permit conditions, the present "average annual
yield" of the SWP is about 2.4 million acre-feet per
year. (SWRCB 7, p. 3L-10.) Average annual yield is the
dependable supply available during a prolonged dry
period, such as a repeat of the 1928-1934 drought.
(NAS&MLC 58, pp. 4-20.) In most years, the SWP has
been able to deliver about 3 to 3.5 million acre-feet.
Entitlement requests are more than 3.7 million acre-feet
per year. (SWRCB 7, p. 3L-10.) Between 1971 and 1990, the
SWP delivered an average of 467 thousand acre-feet per
year to MWD, or about 31.3 percent of MWD's water supply,
with the balance coming from the Colorado River. In the
1989-1990 water year, however, the SWP supplied MWD 1.3
million acre-feet or about 52 percent of MWD's supply.
(SWRCB 7, pp. L-10 and 3L-11.)
In recent years, Endangered Species Act
limitations have significantly reduced the amount of SWP
water that can be delivered. In 1991, DWR established the
California Drought Emergency Water Bank to make water
available to water short areas through water transfers.
The 1991 Water Bank acquired nearly 860 thousand
acre-feet which was sufficient to meet the critical needs
of purchasers with additional water remaining available
for sale. MWD purchased 215 thousand acre-feet from the
Water Bank at a cost of $175 per acre-foot, or
approximately $37.7 million, with pumping costs estimated
to be $142 per acre-foot, or $30.4 million.
The record indicates that LADWP does an
effective job of managing the water it obtains from
various sources. The City of Los Angeles began citywide
water metering in 1902, it has had a conjunctive use
program of surface and ground water since 1920, it has
pursued water recycling since 1970, and it has had a
vigorous water conservation program since 1976. (RT XV,
93:3-93:16; LADWP 65, pp. 2, 3, 84 and 88.) Dr. Timothy
Quinn of MWD testified that Los Angeles has done an
extraordinary job of implementing those water management
measures designated as "best management
practices" by the California Urban Water
Conservation Council. (RT XXV, 42:22-43:14.)
During past drought years, LADWP's water
customers have saved up to 30 percent of normal water
use. (LADWP 65, p. 87.) Los Angeles has 22 water
conservation programs in place including public
education, an ultra low flush toilet retrofit program,
and a tiered water pricing system. (LADWP 65, pp. 87-96;
RT XV, 80:23-81:2; SWRCB 7, pp. 3L-6 to 3L-7.)
7.1.2 Impacts of this Decision on
Water Supplies Available to Los Angeles
The reduction in Mono Basin water exports from the levels
in effect prior to the 1989 preliminary injunction has
had, and will continue to have, a direct effect upon
water supplies available to the City of Los Angeles. The
effects of this decision upon Los Angeles will be
greatest in the early years when Mono Basin diversions
are most severely restricted and will decrease after the
level of Mono Lake reaches 6,391 feet.
Using Version 3.31 of the LAAMP model,
the 1989 "point of reference conditions," and
1941 through 1989 hydrology, the average annual Mono
Basin water exports over a 50-year period would be
approximately 74.5 thousand acre-feet. As described in
the discussion of fishery protection flows, the SWRCB is
required to amend LADWP's licenses to establish instream
flow conditions for protection of fish. Amendment of the
licenses to include only the instream flow and channel
maintenance flows established in this decision would
result in projected average annual exports from the Mono
Basin of approximately 39.3 thousand acre-feet. Thus,
over a 50-year period, fishery protection flows result in
approximately a 35.2 thousand acre-feet reduction in Los
Angeles' water supply from the Mono Basin from the point
of reference condition. During the approximate 20-year
transition period to the target lake level, the impact on
water exports due to fishery protection flow would be
approximately 35.7 thousand acre-feet, assuming a repeat
of 1940-1959 hydrology.
In addition, this decision establishes
conditions for protection of other public trust resources
which will further reduce Mono Basin water exports.
Computer modeling results project that during the first
50-year period of applying the water diversion criteria
established in this decision, LADWP will be able to
export an average annual amount of approximately 21.1
thousand acre-feet. Under the specified water diversion
criteria, however, it is expected that less water will be
available for export during the estimated 20-year period
in which the lake is projected to rise to approximately
6,391 feet, and more water available for diversion in
later years. Computer modeling indicates that LADWP will
be able to divert an average of approximately 12.3
thousand acre-feet per year during the first 20 years.
Once the lake reaches 6,391 feet, LADWP's
average annual Mono Basin exports are projected to
increase to 30.8 thousand acre-feet. Thus, in comparison
to the point of reference, the net effect of this
decision will be to reduce average annual Mono Basin
exports to Los Angeles by 43.7 thousand acre-feet.
Over the first 20 years, the additional
reduction in water exports due to protection of
non-fishery public trust resources in the Mono Basin is
projected to be approximately 32.3 thousand acre-feet per
year. After a lake level of 6,391 is reached, the
reduction in exports due to protection of non-fishery
public trust resources is approximately 8.5 thousand
acre-feet per year.
Beginning in 1989, a preliminary
injunction has prevented Los Angeles from diverting water
from the Mono Basin. As a result, Los Angeles already has
experienced five years of dealing with the loss of
previously available water from the Mono Basin. Los
Angeles' future water supply and demand situation is
discussed below.
7.1.3 Future Water Supply and Demand
Conditions in Los Angeles
LADWP projects that the city will use approximately 700
thousand acre-feet per year by 1995, increasing to 756.5
thousand acre-feet by 2010 due to population growth.
LADWP cautions, however, that large uncertainties exist
regarding future projections. (LADWP 65, p. 82; Figure 1,
p. 83.) Although Los Angeles water use exceeded 700
thousand acre-feet during 1987, the City's vigorous water
conservation programs during successive drought years
reduced water use by more than 20 percent between March
1991 and April 1992. Reduction in water use due to water
conservation remained above 15 percent after drought
conditions ended, which suggests that a permanent change
in water use patterns has been achieved. (LADWP 65, p.
86.) A number of alternatives are available to LADWP to
help offset water losses from the reduction of Mono Basin
exports. These include increased use of local ground
water, continued water conservation programs, reclamation
and recycling, and obtaining additional water supplies
from MWD. Each of these alternatives is addressed below.
Local Ground Water: LADWP pumps
ground water from the San Fernando Basin and three other
local ground water basins that are regulated by a
watermaster in accordance with ground water adjudication
decrees. LADWP estimates that it can increase average
annual yield from ground water by 20 thousand acre-feet
up to a total of 132 thousand acre-feet. The increase is
due to credit that LADWP will receive for water that it
imports into the San Fernando Valley which percolates to
the ground water basin. (SWRCB 7, p. 3L-12.)
Water Conservation: The record
establishes that the City of Los Angeles and its
residents have an excellent record of water conservation.
Some of the water conservation measures used to date,
such as drought tolerant landscaping and retrofitting
with ultra-low flush toilets, will continue to have
long-term benefits. Other measures such as rationing
would not be expected to be employed except during
critical water shortages.
Reclamation and Recycling:
Considerable evidence was introduced regarding the
potential for increased reclamation and recycling of
water in the LADWP and MWD service areas. LADWP projects
that reclaimed water could replace 160 thousand acre-feet
of water from other sources in the MWD service area,
approximately 80 thousand acre-feet of which will be
available for use in LADWP's service area. The remainder
of the reclaimed water will serve to release other MWD
water for use elsewhere. (LADWP 65, p. 88; RT XV,
90:15-91:9.) LADWP intends to recycle 40 percent of its
wastewater and to use recycled water to displace 10
percent of its potable supply by 2010. (LADWP 65, p. 89.)
LADWP's Water Procurement Adjustment Fund
may provide funding of up to $45 million per year for
additional recycling projects. (RT XV, 133:25-134:12.) To
date, LADWP has decided to limit water reclamation
projects to those costing less than $600 per acre-foot,
based on assumed costs of water from MWD in the near-term
future. (RT XL, 75:10-76:4.)
Dr. Quinn of MWD testified that water
reclamation in Southern California will reach as high as
670 thousand acre-feet in the next 20 years. (RT XXV,
58:17-58:19.) MWD supports water reclamation through its
Local Projects Program which offers a rebate of $154 for
each acre-foot of water generated by a local agency. (RT
XXV, 56:14-57:2; RT XV, 163:3-163:19.) Additional funding
for water reclamation programs is also available to Los
Angeles from the federal government under the provisions
of Section 1613 of the Reclamation Projects Authorization
and Adjustment Act of 1992 (HR 429) and from the State
under the provisions of the Environmental Water Act of
1989 (California Water Code Section 12929, et seq. [AB
444]). The sources of financing available for replacement
water are dependent upon the type of projects that LADWP
chooses to pursue.
Supplies From Metropolitan Water
District: The portion of LADWP's water demand that
cannot be met from local ground water supplies, Los
Angeles Aquifer deliveries, and water reclamation will
very likely be met by MWD. In 1990, LADWP requested 197
thousand acre-feet of water from MWD, but it was entitled
to receive 639 thousand acre-feet. LADWP expects to
request 212 thousand acre-feet per year by 2010, by which
time its contractual entitlement will have declined to
about 602 thousand acre-feet. (SWRCB 7, p. 3L-13.) In
view of LADWP's large contractual entitlements from MWD
under a first priority right, the issue is whether MWD
will have sufficient water available to meet an increase
in LADWP's demand. Although MWD currently represents one
of LADWP's least expensive sources of additional water,
LADWP has decided to develop its own more expensive
resources because of its perception of uncertainty
concerning MWD supplies. (SWRCB 7, p. 3L-14.)
MWD's objective is to meet 100 percent of
"full-service" demand at least 90 percent of
the time. Full-service demand is defined as wholesale
demand for imported water after accounting for
implementation of water management programs and best
management practices within the service area. Another MWD
objective is to require extraordinary demand reduction
only infrequently, with moderate demand reduction
programs occurring in about eight percent of all years.
Serious rationing with economic consequences comparable
to those occurring during drought year 1991 would occur
only two percent of the time. (MWD 1, p. 5.)
MWD's primary sources of supply are the
SWP and the Colorado River. The availability of water to
MWD from the SWP will depend in part upon future
restrictions that are placed on water diversions from the
Sacramento-San Joaquin Delta area. Dr. Quinn testified
that "flexibility" is central to the issue of
water available for diversion by the SWP in the Delta.
(RT XXV, 48:4-48:12.) With sufficient flexibility in the
Delta, Dr. Quinn believes that there is a potential for
more SWP deliveries, increased use of ground water
storage during wet periods, and expanded water transfers.
(RT XXV, 16:14-16:22.) Testimony was also presented
concerning a recent water transfer to MWD involving water
that is currently exported for irrigation south of the
Delta. (MWD 1, pp. 9 and 10.) Transfers to MWD or LADWP
of water that is presently used south of the Delta would
avoid issues raised by an increase in Delta exports.
LADWP's analysis of water available to
MWD assumes that MWD will obtain only 626 thousand
acre-feet from the Colorado River Aqueduct. (CT 25,
Appendix 1.) MWD presented testimony, however, that it
expects to maintain a full Colorado River Aqueduct
receiving 1.2 million acre-feet per year. (RT XV,
19:1-19:3.) This difference of nearly 600 thousand
acre-feet is several times greater than the total amount
of water that LADWP has ever diverted from the Mono
Basin. In view of MWD's testimony and its success in
obtaining Colorado River water in recent years, it is
reasonable to conclude that MWD's average water
deliveries from the Colorado River Aqueduct will continue
to substantially exceed the 626 thousand acre-feet
estimate used in the LADWP analysis.
7.1.4 Impacts of this Decision on
Water Quality in Los Angeles
Water
exported from the Mono Basin is low in dissolved minerals
and easily meets all state and federal drinking water
standards. (RT XV, 5:11-6:15.) Mono Basin water can be
used to dilute naturally occurring minerals in the Owens
River such as arsenic. (RT XV, 5:16-5:17.)
Although the City of Los Angeles water
supply meets the current arsenic standard of 50 mg/l, testimony was presented that
the U.S. EPA will soon propose a more stringent arsenic
standard which would go into effect in 1998. (RT XV,
5:16-6:12, 29:1-29:3.) If the new arsenic standard is
very stringent, it may be necessary to use blending, a
new treatment plant at Hot Creek, and/ or additional
treatment facilities at the Los Angeles Aqueduct
filtration plant. (RT XV, 6:15-6:21.) Testimony from
LADWP indicates that it may be necessary to construct the
water treatment plant for arsenic, with or without the
continued diversion of water from the Mono Basin. LADWP
is currently performing preliminary studies to assess the
feasibility of different options for complying with the
anticipated new arsenic standard. (RT XV, 29:4-29:14.)
Water from the Mono Basin is of very high quality and, in
sufficient quantities, it would serve a valuable dilution
function with respect to other water delivered through
the Los Angeles Aqueduct. After accounting for the
quantity of water needed for fishery protection in the
Mono Basin, however, the amount of water remaining in
dispute is considerably reduced. Computer modeling
indicates that, on average, long-term protection of
public trust uses in the Mono Basin will require an
additional 8.5 thousand acre-feet of water per year. The
dilution function served by restoring this relatively
small amount of water to a water system serving over 600
thousand acre-feet of water per year would be relatively
small.
7.1.5 Economic Costs of Reduced Mono
Basin Water Supply for Municipal Use
Under the point of reference conditions described in the
Draft EIR, Version 3.31 of the LAAMP model estimates
average annual exports over a 50-year period of 74.5
thousand acre-feet per year. Amendment of the licenses to
include the instream flows and channel maintenance flows
established in this decision would result in average
annual exports from the Mono Lake Basin of approximately
39.3 thousand acre-feet. Protection of public trust
resources would reduce Mono Basin water exports by an
additional 8.5 thousand acre-feet per year once a lake
level of 6,391 feet has been reached. During the
approximately 20-year period that it will take to reach
6,391 feet, restoration and protection of public trust
resources will reduce Mono Basin water exports by
approximately 32.3 thousand acre-feet, in addition to the
reduction in water exports due to fish flows.
Reduced water exports from the Mono Basin
which are necessary to correct the damage caused by past
diversions will result in additional water supply and
power costs to LADWP and its customers. The amount of
these costs depend upon the following:
(1) The cost of water conservation
programs to reduce demand in the LADWP service area.
(2) The cost of procuring replacement
water needed to meet demand when it is not economical to
reduce demand further by conservation programs.
(3) A cost assigned to the expense and
inconvenience imposed on customers as a result of water
shortages in years when LADWP is unable to procure
sufficient water to meet demand in its service area
(i.e., "water shortage costs").
(4) Cost of replacement power as
discussed in Section 7.2.
As discussed in Sections 7.1.1 through
7.1.3, there is strong evidence that replacement water
will be available to Los Angeles from a variety of
sources. Although the cost of the replacement water will
exceed the cost of water from the Mono Basin, reduced
Mono Basin diversions resulting from this decision should
not result in shortage costs due to unavailability of
replacement water.
The cost of replacing water by water
conservation programs, water recycling, and procurement
from MWD would vary from $300 per acre-foot for water
conservation programs to about $700 per acre-foot for the
most expensive reclamation project under consideration by
LADWP. (LADWP 160, p. A-15.) The current cost of water
purchased from MWD is $230 per acre-foot. (SWRCB 7, Table
3N-12.) According to testimony of MWD, the full
incremental cost in the near term of delivering new
supplies of water to the MWD service area is expected to
be $350 to $400 per acre-foot. (RT XXV 54:11-54:20.)
The total cost of replacing water lost as
a result of this decision will vary from year to year
depending on the proportion of replacement water from
each source. Replacement water will be more expensive in
dry years than in normal and wet years.
LADWP and the Natural Heritage Institute
(on behalf of Cal Trout) both used computer models to
estimate the cost of reducing deliveries from the Mono
Basin. Neither of the analyses that were presented
provides a satisfactory estimate of the cost of
replacement water over a series of wet, normal, and dry
years, because the computer models' cost projections
include a variety of other costs with the water
replacement costs, and because the computer models
include some assumptions that are unrealistic or could
not be verified. For example, the LADWP analysis assumes
that insufficient replacement water will be available
thereby causing high water shortage costs to be imposed
on water users in Los Angeles. This assumption does not
appear realistic in light of the evidence discussed in
Section 7.1.3. On the other hand, the analysis by the
Natural Heritage Institute contained a variety of
assumptions concerning how water use in LADWP service
area will be affected by pricing and water conservation
measures. The SWRCB was unable to verify whether the
assumptions used in the Natural Heritage Institute's
analysis were realistic.
Due to the limitations of the analyses
presented by LADWP and the Natural Heritage Institute,
the SWRCB developed a separate estimate of the cost of
replacement water based on evidence in the record. The
method by which the cost estimate presented in this
decision was developed is described below in Section
7.1.6. For the reasons explained in that section, the
actual costs may be significantly lower than the costs
assumed for purposes of this decision.
The SWRCB's estimates for replacement
water are based upon comparison of LADWP's projected Mono
Basin water exports under the terms of this decision with
the exports that would have been expected if the 1989
point of reference conditions had continued. It should be
recognized that LADWP has been obtaining replacement
water for former Mono Basin supplies since 1989,
primarily through increased deliveries from MWD. The
primary water supply and financial effect of this
decision will be a continuing requirement for LADWP to
obtain replacement water for a large portion of the water
formerly exported from the Mono Basin.
As described in Section 7.1.6 below, the
SWRCB's cost estimates indicate that the average annual
cost of requiring instream flows and channel maintenance
flows for fishery protection purposes would be about
$14.5 million. Under the previously discussed Court of
Appeal decision in Cal Trout II, however, the
flows required for fishery protection purposes in this
instance are mandatory. Flows needed to reestablish and
maintain the fishery are not subject to reduction due to
economic cost. The additional cost of protecting public
trust values by reducing diversions further to allow the
lake level to rise to 6,391 feet in a reasonable period
of time would be approximately $13.3 million per year
over the next 20 years.
The cost after the transition period
would be significantly lower because LADWP will be able
to increase diversions once public trust resources are
restored to the level of protection provided by
maintaining the elevation of Mono Lake above 6,391 feet.
The actual costs will depend on water replacement costs
in the mid-twenty-first century. An analysis based on
near-term water replacement costs indicates that, after
the transition period, the water supply cost of
protecting public trust resources will average about $3.4
million annually. This cost is in addition to the $14.5
million annual cost of providing replacement water for
the reduction in Mono Basin exports attributable to
fishery protection flows. The method of determining the
estimated cost of providing the fishery protection flows
and the additional water needed for protection of public
trust resources is described below.
7.1.6 Estimation of Average Cost of
Replacement Water
The SWRCB's estimate of the average costs of replacement
water is based on a base replacement cost of $400 per
acre-foot. This cost is at the upper end of the range
stated as the cost of new water supplies from MWD.
Replacement water is likely to be more expensive in dry
years and less expensive in wet years. Consequently, the
base cost was adjusted by a factor giving the relative
cost of MWD water in dry, normal, and wet years to
provide an estimate of the average replacement cost of
water in dry, normal, and wet years. (LADWP 160, p. 8.)
This adjustment gives the following water replacement
costs:
Dry year average $430/acre-foot
Normal year average $400/acre-foot
Wet year average $370/acre-foot
To provide a conservative estimate of
costs, an additional 20 percent was added to the
replacement cost in dry years. Thus, the water
replacement costs used in the calculations were as
follows:
Dry year average $520/acre-foot
Normal year average $400/acre-foot
Wet year average $370/acre-foot
The average amount of replacement water
needed in each type of year during the transition to the
protected lake level was estimated in the following way.
The LAAMP model (Version 3.31) was used to estimate
exports from the Mono Basin over a 20-year period under
each of three scenarios:
(1) The point of reference scenario
described in the EIR;
(2) A scenario based on limiting
diversions in order to provide instream flow for
protection of fish (referred to as the "Fish Flow
Scenario"); and
(3) A scenario where diversions are
reduced further in order to provide fishery protection
flows and to protect public trust resources in
accordance with the transition period diversion criteria
specified in Section 6.8 above (referred to as "Fish
Flow plus Public Trust Scenario").
The amount of replacement water needed to
offset reduced exports from the Mono Basin is
conservatively estimated as the difference in Mono Basin
exports under the point of reference conditions and under
each of the other scenarios. In reality, less replacement
water may be needed because it may be possible to
partially offset the reductions in exports from the Mono
Basin by taking more water from other sources along the
Los Angeles Aqueduct. In addition, some of the water
exported from the Mono Basin is lost in transit to Los
Angeles. For purposes of estimating the cost of complying
with this decision, however, it was assumed that
reductions in Mono Basin exports would require obtaining
an equal amount of replacement water from other sources.
Table 15 below shows the estimated
quantities of replacement water needed to satisfy the
fishery protection flows, the additional quantity of
replacement water needed to restore the lake level to
protect other public trust uses, and the estimated total
quantity of water needed to meet fishery protection flows
and to protect other public trust uses. The figures in
Table 15 are for the estimated 20-year transition period
which will be needed for the water level of Mono Lake to
reach 6,391 feet.
TABLE 15:
REPLACEMENT WATER NEEDED DURING TRANSITION PERIOD
(ACRE-FEET)
SCENARIO
|
DRY YEAR
AVERAGE
(20% of years)
|
NORMAL
YEAR
AVERAGE
(60% of years)
|
WET YEAR
AVERAGE
(20% of years)
|
AVERAGE
OVER
20 YEARS
|
REPLACEMENT
WATER
TO MEET "FISH FLOW
SCENARIO"
|
25,700
|
37,400
|
37,800
|
35,700
|
ADDITIONAL
REPLACEMENT
WATER TO MEET PUBLIC
TRUST REQUIREMENT
|
19,600
|
31,000
|
51,200
|
32,300
|
TOTAL
REPLACEMENT
WATER TO MEET
"FISH FLOW PLUS
PUBLIC TRUST SCENARIO"
|
45,300
|
68,400
|
89,000
|
68,000
|
The average water replacement costs in
the three hydrologic year types were estimated by
applying the replacement costs for each year type to the
average amount of water needed in that year type. The
average annual water replacement cost over all year types
was estimated by weighing these amounts over the relative
frequencies of the three year types, assuming 20 percent
dry years, 60 percent normal years, and 20 percent wet
years.
The resulting costs during the estimated
20-year transition period are as follows: (1) the
estimated average annual water replacement cost of
meeting the fish flow requirement is approximately $14.5
million; and (2) the additional estimated average annual
cost of protecting public trust resources is
approximately $13.3 million. In the first several years,
actual costs are likely to be less than these figures
because the actual replacement cost of water is likely to
be closer to the current cost of water from MWD than to
the costs used in this analysis.
An additional analysis of replacement
water cost was conducted for the period after the lake
has reached 6,391 feet. The LAAMP model (Version 3.31)
was used to estimate exports from the Mono Basin over a
50-year period under each of three scenarios:
(1) The point of reference scenario
described in the Draft EIR;
(2) A scenario based on limiting
diversions in order to provide instream flow for
protection of fish (referred to as the "Fish Flow
Scenario"); and
(3) A scenario where diversions are
reduced further in order to provide fishery protection
flows and to protect public trust values in
accordance with the post-transition period diversion
criteria specified in Section 6.8 above (referred to as
"Fish Flow plus Public Trust Scenario").
This analysis indicated that the
additional replacement water, over and above that needed
to meet the fish flow requirement, necessary to maintain
the lake near a protected level of 6,391 feet would
average 4,100 acre-feet in dry years, 10,900 acre-feet in
normal years, 5,000 acre-feet in wet years. Over the
50-year period an average of 8,500 acre-feet per year
would be required. The resulting water replacement costs
would average $3.4 million over the 50-year period. This
cost is in addition to the approximately $14.5 million
annual cost of providing replacement water for the
reduction in Mono Basin exports attributable to fishery
protection flows.
7.1.7 Conclusions Regarding Water
Supply for Municipal Use
The quantity of water available to Los Angeles in the
future depends to a large extent upon water availability
to MWD and LADWP's success in implementing proposed water
reclamation projects. MWD has been able to meet LADWP's
increased demands over the last several years and the
evidence in the record indicates it is very likely that
MWD will continue to have sufficient water available to
meet LADWP's needs in the future. In addition, if LADWP
vigorously pursues the water reclamation projects that it
presently is developing, then reclaimed water will
provide a substantial augmentation to Los Angeles'
supplies within the next decade. Thus, the SWRCB
concludes that there will continue to be sufficient water
available to meet the municipal needs of Los Angeles when
diversions from the Mono Basin are restricted in
accordance with the water diversion criteria discussed in
Section 6.8.
Due to uncertainty about future hydrology
and future water availability throughout the state, it is
difficult to develop an accurate estimate of the cost of
securing replacement water supplies for water formerly
diverted from the Mono Basin. For purposes of determining
the feasibility of the water right license amendments set
forth in this decision, the SWRCB believes that the cost
estimates presented in Sections 7.1.5 and 7.1.6 above
provide a reasonable approximation of the expense
involved in securing replacement water. The availability
of funding from the sources discussed in Section 7.1.3
makes it likely that the cost to LADWP ratepayers of
securing replacement supplies will be less than estimated
above.
The SWRCB recognizes that a complete
economic analysis of the effects of this decision would
also examine the economic benefits of protecting fishery
and public trust resources in the Mono Basin.
Considerable information regarding these economic
benefits was provided in the Draft EIR and other evidence
presented at the water right hearing. Rather than delve
further into the speculative area of projecting future
economic costs and benefits, the SWRCB chooses to focus
on examining whether the economic costs of this decision
make its adoption infeasible. Based on the evidence in
the record, the SWRCB concludes that neither the water
supply costs nor the power supply costs (see Section 7.2)
make it infeasible to protect public trust resources in
the Mono Basin in accordance with the terms of this
decision.
The EIR concludes that the 6,390-feet
alternative would have significant water supply impacts
upon Los Angeles but that those impacts can be mitigated
by securing funding for replacement water from various
sources. The lower lake level alternatives identified in
the EIR would have less impact on Los Angeles' water
supplies, but also would provide less protection for
public trust resources in the Mono Basin. Specifically,
these alternatives would provide less protection for fish
and wildlife, and would not attain air and water quality
standards. The SWRCB concludes that the appropriate
balance between protection of public trust resources in
the Mono Basin and the adverse impacts of reducing Mono
Basin water exports calls for a target lake level above
6,390 feet. Therefore, alternatives which would result in
a significantly lower lake level are not a feasible means
of reducing adverse impacts on Los Angeles' water supply.
The EIR identifies as potential
mitigation measures a number of avenues Los Angeles may
pursue to obtain or develop replacement water supplies.
These include water reclamation projects, using funds
available under AB 444, participating in water transfers
under the Central Valley Project Improvement Act (Title
XXXIV of HR 429), participating in MWD's water
reclamation and groundwater recovery rebate program, and
implementing and monitoring compliance with urban water
conservation best management practices.
The record establishes that Los Angeles
has been pursuing new water supplies from various
sources. The record also indicates that Los Angeles (or,
in the case of water transfers under HR 429, MWD) is
pursuing the measures identified in the EIR as means of
obtaining replacement supplies. These actions are the
primary responsibility of Los Angeles, which has a strong
incentive to continue pursuing development of the water
supplies it needs. Therefore, the SWRCB concludes that to
amend Los Angeles' water rights to require specific
actions to pursue additional water supplies: (1) would
not be an appropriate means of mitigating adverse water
supply impacts of this decision; and (2) should be deemed
infeasible for purposes of CEQA, because it would
unnecessarily interfere with the management of Los
Angeles' operations. Overall, the adverse water supply
impacts of this decision are overridden by the legal
requirement to provide flows to reestablish and maintain
the pre-1941 fishery in the four tributary streams, and
by the benefits of this decision to fishery and other
public trust resources in the Mono Basin.
Although the SWRCB concludes that Los
Angeles' need for water for municipal use does not make
it infeasible to protect public trust resources in the
Mono Basin, the SWRCB also recognizes that there is, and
there will continue to be, a long-term water supply
problem in Southern California and other areas of the
State. Therefore, water diversions from the Mono Basin
should not be unnecessarily restricted beyond what is
necessary to provide reasonable protection for public
trust resources in the Mono Basin as addressed in this
decision.
7.2 Hydroelectric Power Production
Water exported from the Mono Basin is used to generate
hydroelectric power as the water passes through power
plants on the Los Angeles Aqueduct. A reduction in the
amount of water exported from the Mono Basin will result
in reduced power generation and increased cost to Los
Angeles to obtain power from other sources. In addition,
the reduction in hydroelectric power production could
have an adverse impact on air quality. (See Section 8.4.)
As shown in Table 15 above, amendment of
Los Angeles' licenses to include the instream flows and
channel maintenance flows established in this decision
would reduce annual exports from the Mono Lake Basin by
an average of approximately 35.7 thousand acre-feet
during the 20-year transition period. Reducing diversions
in order to reach and maintain a lake level near 6,391
feet in accordance with the previously specified water
diversion criteria would result in reducing deliveries by
approximately 32.3 thousand acre-feet more. After the
transition to the protected lake level, diversions could
be increased again to a level which would result in
annual average exports to Los Angeles of approximately
8.5 thousand acre-feet less than would be the case if
only the fishery flow requirements were added to LADWP's
licenses.
The City of Los Angeles, the Mono Lake
Committee, and the National Audubon Society concur that
the cost of replacing energy generated by power plants on
the Los Angeles Aqueduct will be approximately $125 per
acre-foot. (CT 47, Table 1.) The average annual cost
of reduced power production due to the fishery protection
flows would be approximately $4.5 million. Until the
water level of Mono Lake reaches 6,391 feet, protection
of public trust resources will result in annual energy
costs approximately $4.0 million greater than the energy
costs that would be incurred if only the fish flow
requirements were met. After the transition period, the
annual energy costs would be approximately $1.1 million
greater than the costs that would be incurred if only the
fish flow requirements were met.
The cost of power supplied by Southern
California Edison to much of the area adjacent to LADWP's
service area is approximately 20 percent higher than
LADWP's cost. (RT XXIII, 179:18.) Therefore, the increase
in power costs to LADWP ratepayers due to loss of Mono
Basin water is not considered to impose a significant
hardship on LADWP electricity customers. As with the
water supply costs, it should be recognized that LADWP
customers have been paying the cost of obtaining
replacement power from other sources since 1989.
7.3 Summary of Costs of Obtaining
Replacement Water and Power Due to Reduced Mono Basin
Diversions
Los
Angeles will incur economic costs due to reduction of
water exports from the Mono Basin. Based on the
information presented in Sections 7.1.5 and 7.2 above,
water supply replacement costs during the approximate 20
year transition period are estimated to be approximately
$27.8 million per year and power replacement costs are
estimated to be approximately $8.5 million per year. The
total estimated costs for replacement of water and power
during the transition period are approximately $36.3
million per year. Slightly over half of the estimated
costs are due to the fishery protection flows, and the
remainder are due to the need for additional water to
raise the water level of Mono Lake to protect public
trust uses.
Once the water level of Mono Lake has
reached 6,391 feet above sea level, water exports are
expected to increase, and water and power replacement
costs are expected to decrease. Water supply replacement
costs after the transition period are estimated to be
approximately $17.9 million per year, and power supply
replacement costs are estimated to be approximately $5.6
million per year. The total estimated costs for
replacement of water and power after the transition
period are approximately $23.5 million per year.
Approximately 80 percent of the estimated long-term costs
are due to the fishery protection flows, and the
remainder are due to the need for additional water to
maintain Mono Lake at a water level sufficient to protect
public trust uses.
8.0 POTENTIAL ADVERSE ENVIRONMENTAL
IMPACTS OF REDUCED MONO BASIN WATER DIVERSIONS
Effects
of Rising Lake Level on Sand Tufa
As explained in
the discussion of visual and recreational resources, many
of the sand tufa formations at Mono Lake will be lost at
lake levels above 6,384 feet. LADWP's rebuttal brief
argues that the LADWP Mono Lake Management Plan is the
only proposal which is consistent with Public Resources
Code Section 5046 which calls for protection of the sand
tufa. (LADWP Rebuttal Brief, p. 56.) Public Resources
Code Section 5049, however, expressly provides that
natural or artificially caused accretion or reliction of
the waters of Mono Lake shall not be deemed contrary to
the purposes of the law establishing the Mono Lake Tufa
State Reserve. In addition, the evidence establishes that
the higher water levels expected to occur under the LADWP
plan would also adversely impact the sand tufa.
The sand tufa structures which are in
question were not visible prior to 1941 because they were
formed under the lake bottom. Dr. Stine's research
indicates that, even if the lake level did not increase,
the sand tufa would be expected to undergo pronounced
weathering and erosion over the next 50 years.
(NAS&MLC 1AF, p. 1.) The primary agencies with land
management responsibility in the Mono Basin, including
the Department of Parks and Recreation which manages the
Mono Lake Tufa State Reserve, all recommend adoption of
the 6,390 feet alternative described in the Draft EIR.
The SWRCB considers loss of sand tufa
structures at Mono Lake to be a significant adverse
impact. The only measure which would mitigate adverse
impacts on sand tufa to less than a level of significance
would be to maintain the level of Mono Lake at 6,384 feet
or less. (See Section 6.5.4.) However, establishment of
the mandatory fishery protection flows in the four
streams from which LADWP diverts water is expected to
result in an average long-term lake level over 6,388
feet. The legal requirement to establish fishery
protection flows makes it infeasible to preserve a
long-term lake level of less than approximately 6,388
feet. Therefore, the legally required fishery protection
flows are an overriding consideration justifying
amendment of LADWP's water right licenses despite the
impacts on sand tufa. The SWRCB also finds that, even in
the absence of a legal mandate to establish fishery
protection flows, the benefits of protecting other public
trust resources at Mono Lake constitute a separate basis
for our conclusion that overriding considerations justify
a higher lake level despite adverse impacts to sand tufa.
(14, CCR, § 15093.)
8.2 Lake Fringing Vegetation
The term "wetlands," as
used in the Draft EIR, is based on the USFWS definition
which encompasses areas that do not meet the U.S. EPA or
the Corps of Engineers definition of wetlands for
implementation of Section 404 of the Clean Water Act.
Applying the USFWS definition, one result of the
declining water elevation at Mono Lake is that the area
of lake fringing wetlands (excluding dry meadow area)
increased from about 360 acres to 2,800 acres on the
relicted lakeshore. As discussed in Section 6.3.3,
however, the habitat value of the new wetland areas in
the relicted lakebed is much less than the habitat value
of the wetlands which existed prior to 1941. In the
absence of LADWP's diversions, the water level of Mono
Lake today would have been much higher and the wetlands
which developed in the relicted lakebed area would not
exist. (SWRCB 7, Vol. 1, Figure 3A-8.)
A rise in the water level of Mono Lake to
approximately 6,392 feet will result in the loss of over
1,600 acres of wetland in the area of the relicted
lakebed. (SWRCB 7, Table 3C-6.) A portion of the lost
acreage will be mitigated for by the increase in high
value wetland habitat expected to occur at various
locations at a lake elevation above 6,390 feet. (See
Section 6.3.7) Mitigation for the total loss of low value
wetlands would not be feasible due to the large acreage
involved. The U.S. Forest Service considers the loss of
the wetlands which would occur due to a rise in lake
level to be insignificant. (RT XXV, 183:17-184:7.) As
noted in Section 8.3 above, the primary land management
agencies in the Mono Basin all recommend a substantial
increase in the water level of Mono Lake.
In view of the relatively low habitat
value of the wetlands in the relicted lake bed, reduction
of that wetland area is less significant than would be
the case with other wetland areas. Even so, the EIR
identifies submergence of wetlands in the relicted
lakebed area as a significant adverse environmental
effect. The SWRCB finds that submergence of those
wetlands is an unavoidable result of restoring the water
level of Mono Lake to an elevation sufficient to protect
public trust resources. The SWRCB further finds that the
balanced protection of public trust resources which will
be provided by the water diversion criteria established
in this decision is an overriding consideration which
justifies submergence of wetlands in the relicted
lakebed. The legal mandate to establish fishery
protection flows provides a separate basis for the
SWRCB's findings that: (1) overriding considerations
justify the requirements of this decision despite the
submergence of wetlands which will occur as a result; and
(2) that alternatives which would avoid the loss of
wetlands in the relicted lake bed are infeasible.
8.3 Flows in the Upper Owens River
The export of water from the Mono Basin since 1941 has
had various effects on channel structure and flows of the
upper Owens River between East Portal and Lake Crowley.
Prior to Mono Basin exports, the flow in the upper Owens
River was primarily from natural springs in the Big
Springs area which provide a relatively steady rate of
flow. The natural flow above East Portal fluctuated
between a monthly average of 51 cfs and 85 cfs with an
average of approximately 58.5 cfs. (DFG 62, p. 16.)
Between 1941 and 1989, water exports from the Mono Basin
greatly increased the flow in the upper Owens River below
East Portal, but the rate of flow was more variable,
depending upon the quantity and timing of diversions from
the Mono Basin.
The major study of the upper Owens River
fishery presented at the hearing was Owens River Stream
Evaluation Report 93-1 prepared by a consultant to DFG.
(DFG 62.) The study was designed to develop instream flow
recommendations and habitat development and management
plans for the upper Owens River between East Portal and
Lake Crowley. Based on flow recommendations using the
IFIM methodology described previously, the DFG study
estimated that flows of 120 to 250 cfs just downstream of
East Portal would provide habitat within 80 percent of
the maximum values for all life stages of brown trout and
rainbow trout. (DFG 62, pp. 213 and 214.)
Because adult brown trout and rainbow
trout are thought to inhabit the upper Owens River on a
year round basis, optimizing adult habitat conditions
would require a year-round flow regime of approximately
250 cfs. (DFG 62, p. 214.) Maximum habitat for adult
trout was estimated to be provided at 250 cfs, but flows
of that rate would exceed the "minimum bank-full
flow capacity at several locations" and were not
recommended by DFG. (DFG 62, p. i.) To minimize
exceedence of bank-full flow capacity, DFG recommended
that flows not exceed 200 cfs directly below East Portal.
(DFG 3, p. 7.) DFG's recommendations were summarized
as follows:
"If additional water is diverted
from the Mono Lake Basin to the upper Owens River, it
should be diverted in a stable manner on a year round
basis. Futhermore, streamflow, just downstream of East
Portal on the upper Owens River should not exceed 200 cfs
nor should streamflow exceed 270 cfs at the confluence of
Hot Creek." (DFG 3, p. 7.)
Under present conditions, the DFG study
indicates that flows between 120 cfs to 250 cfs just
below East Portal would provide the best fishery habitat.
Based on information presented in the study, a DFG
fisheries biologist concluded that the fishery in the
upper Owens River was in good condition at the lower flow
levels present at the time of the hearing. (RT XXII,
305:9-306:23; DFG 62, pp. 168 and 177.)
LADWP presented testimony by Dr. William
Platts recommending that the upper Owens River receive
bank-full flows at least once every three years for
channel and bank maintenance, and that "riparian
maintenance flows" should occur once every ten
years. Over time, these flows are thought to produce the
vegetation and soils needed to maintain and develop a
stream and surrounding riparian habitat which are in good
condition. (LADWP 136, p. 1.) Dr. Platts disagreed
with DFG's recommendation for a limit of 200 cfs below
East Portal because it was based solely on fishery needs
and did not account for flows needed for bank formation
and channel maintenance. (LADWP 136, p. 2.)
Prior to 1941, flows in the upper Owens
River were relatively steady through the year without the
wide variability characteristic of streams which are
primarily dependent upon widely fluctuating runoff.
Although the character of the stream may have changed
over the years, there is insufficient evidence to
conclude that the present upper Owens River needs the
large channel maintenance and riparian maintenance flows
recommended by Dr. Platts. In view of the conflicting
evidence regarding the effects of high flows on the
stream channel, the SWRCB does not adopt either DFG's or
Dr. Platt's recommendations regarding flow levels for
channel protection and/or maintenance in the upper Owens
River just downstream of East Portal.
Reductions in water diversions to the
Owens Basin from the Mono Basin will reduce the fishery
habitat available from what was present at times under
the point of reference conditions. Reduced Mono Basin
diversions will also reduce the amount of imported water
available to mitigate periodic water temperature and
water quality problems in the upper Owens River which, at
certain times of the year, can be significant. (SWRCB 7,
p. 3D-82 and 3D-83.)
On the positive side, amendments to
LADWP's water right licenses in order to reduce large,
rapid flow fluctuations should have a beneficial effect
upon conditions in the upper Owens River. Increases in
discharge to the upper Owens River at East Portal should
be limited to 20 percent of the previous day's flow and
decreases in discharge should be limited to 10 percent of
the previous day's flow. (LADWP 136, p. 2.) In addition,
LADWP should be required to make a good faith effort to
schedule any releases into the upper Owens River at a
relatively stable rate, consistent with operational
limitations and water availability. Finally, in order to
avoid adverse impacts of extremely high flows due to Mono
Basin water diversions, the SWRCB concludes that LADWP's
licenses should be amended to limit water diversions from
the Mono Basin so that the combined natural flow at East
Portal and the discharge from East Portal do not exceed
250 cfs as measured directly below the East Portal
discharge.
This decision is not expected to have a
significant effect on channel conditions in the upper
Owens River. Adverse impacts on upper Owens River fishery
habitat caused by reducing water exports from the Mono
Basin can be partially mitigated through requirements
which prevent rapid fluctuations in the exports which do
occur. In addition, once the water level of Mono Lake
increases above 6,377 feet, the water diversion criteria
established in this decision allow for a resumption of
water exports from the Mono Basin. The resultant increase
in flows in the upper Owens River will increase the
amount of fishery habitat in that stream. To mitigate
adverse impacts on upper Owens River fishery habitat to
less than a level of significance, however, would require
diversion of large quantities of water from the Mono
Basin in order to maintain the approximate quantity of
fishery habitat in the upper Owens River which occurred
prior to the 1989 preliminary injunctions.
The legal requirement to provide fishery
flows in the Mono Basin streams, and the need to further
limit Mono Basin water diversions to protect public trust
resources, makes it infeasible to export sufficient water
from the Mono Basin to mitigate below a level of
significance the adverse impacts on fishery habitat,
water quality and water temperature in the Owens River.
Therefore, the SWRCB concludes that protection of
fisheries and public trust resources in the Mono Basin is
an overriding consideration which justifies the adverse
impacts that reduced Mono Basin water diversions will
have in the upper Owens River Basin.
8.4 Air Quality Impacts Due to
Alternative Methods of Electrical Power Production
The limitations on Mono Basin water exports under the
terms of this decision correspond to limitations on
hydroelectric power production as discussed in Section
7.2. Depending upon how Los Angeles compensates for the
continuing loss of hydroelectric power production, there
could be adverse air quality impacts. The Draft EIR
established criteria for determining the significance of
expected air quality impacts based on the quantity of
emissions from LADWP's power generation facilities in the
Los Angeles Basin and the overall quantity of additional
out-of-basin emissions. (SWRCB 7, pp. 3M-12 and 3M-13.)
The power supply impacts of this decision are in between
the impacts evaluated in the Draft EIR for the 6,390 feet
alternative and the 6,410 feet alternative. The Draft EIR
projected that the lost power production under both
alternatives would be compensated for primarily by an
increase in energy generation in the Los Angeles Basin.
(SWRCB 7, pp. 3M-19 and 3M-20.) Applying the criteria
established in the Draft EIR, the additional emissions
due to compensating for lost power production would not
be considered significant. (SWRCB 7, pp. 3M-19 and
3M-20.)
The actual air quality impacts of reduced
Mono Basin water exports depend upon how Los Angeles
chooses to respond to the loss of reduced hydroelectric
power production. In addition to replacement of lost
power through generation at LADWP facilities or purchase
from out-of-basin sources, increased energy conservation
could offset a portion of the loss with no adverse impact
on air quality. The point of reference conditions,
against which environmental impacts are evaluated for
purposes of the EIR, existed prior to the temporary
cessation of Mono Basin water exports under the
preliminary injunction in 1989. It is important to
recognize that this decision will not result in an
additional reduction in the level of hydroelectric power
generation beyond that which has already occurred.
Rather, as the water level of Mono Lake rises, LADWP will
be able to increase Mono Basin water exports and recover
a portion of the water previously available for export
and hydroelectric power production.
8.5 Cultural Resources
The term cultural resources encompasses sites, features,
and locations of archeological, historical, architectural
and ethnohistorical origins. These can date from an
estimated 10,000 years ago to historic and architectural
resources as recent as 50 years ago. Cultural resources
can even be contemporary, as in ceremonial locations and
traditional food gathering areas used by present Native
Americans. Most cultural resources consist of areas
defined by the presence of physical remains such as
artifacts or structural debris, but they may also consist
of a location with no defining physical characteristics
where a significant historical event occurred, or where
on-going Native American religious activities are held.
The limited cultural resource
investigations done for the environmental impact report
consisted of an archeological records check and
literature search, contacts with several archeologists
who have done research in the Mono Lake area, and a field
assessment of 15 previous recorded cultural resources.
(SWRCB 7, pp. 3K-1 to 3K-2.) That work was designed
to gauge the cultural resource sensitivity of the Mono
Basin rather than to provide a comprehensive inventory of
cultural resources within the potential impact zone.
The archeological field reconnaissance on
Mono Basin streams, in conjunction with pre-field
research, indicates a high level of archeologic
sensitivity. Settlement patterns projected from other
archeological surveys and ethnographical studies in the
Mono Basin area indicate an extensive
prehistoric/ethnographic use of the riparian corridor
areas such as those existing along the Mono Lake
tributaries.
8.5.1 Applicable Legal Requirements
The principal State policy
for the protection of cultural resources is provided by
the California Environmental Quality Act and the CEQA
Guidelines. The procedures for protection, preservation,
and/or mitigation of cultural resources are set forth in
Appendix K of the CEQA Guidelines. If a project may cause
damage to an "important archeological
resource," as defined in Appendix K of the CEQA
Guidelines, the project may have a significant effect on
the environment.
Additional laws provide for the
protection of Native American remains and outline the
procedures to be followed if remains are found (e.g.,
Health and Safety Code Section 7052 and Public Resources
Code Section 5097.) Projects which will have impacts on
federal lands, which will require a federal permit, or
which are federally funded, are subject to Section 106 of
the National Historic Preservation Act of 1966 (as
amended) and its implementing regulations. (Title 36,
Code of Fed. Regs (CFR), Part 800.) Appendix K to the
CEQA Guidelines states that a public agency may use the
documentation prepared under federal guidelines in place
of other documentation needed for CEQA . Cultural
resources assessed as significant in the federal process
would also be considered "important" in the
CEQA process.
8.5.2 Potential Effects of This
Decision on Cultural Resources
The
main channels of the four diverted streams have been
receiving almost all available flow since 1989, so any
additional effects of the flows required under this
decision on the main channels should be limited. Due to
extensive cultural resources in the riparian corridors of
the Mono Basin streams, it is very likely that reopening
of historic stream channels and other stream restoration
work would have impacts to cultural resources. In
addition to the actual restoration work, related
activities such as vehicular access, the quarrying of
gravels and boulders used as restoration materials, and
the disposal of spoils could all have potential adverse
impacts on cultural resources. The increased recreational
use along the riparian corridors of Lee Vining, Walker,
Parker, and Rush Creeks, which would be expected to occur
with the restoration of continuous flow and the
fisheries, is a secondary source of potential adverse
impacts. Impacts could be either inadvertent (e.g.,
increased vehicular use) or deliberate (e.g., vandalism
and unauthorized collection).
The photo documentation of the
restoration work done in 1991 and 1992 shows major
streambed and bank modifications, including excavations
of silted pools, backwater areas and overflow channels.
(NAS&MLC 126 and 174.) Much of this work appears to
have been done with a large treaded backhoe that would
produce extensive subsurface disturbance. If any similar
work is done in the future, it should be conducted in
accordance with the procedures established in this
decision.
8.5.3 Mitigation for Potential Adverse
Impacts to Cultural Resources
The nature and extent of potential impacts to cultural
resources in the Mono Basin due to amendment of Los
Angeles' water right licenses will depend upon the type
of work proposed under the restoration plans to be
developed under the terms of this decision. As the party
responsible for preparation of the restoration plans, and
implementation of those plans once they have been
approved by the SWRCB, LADWP also will be responsible for
evaluating potential effects on cultural resources in
accordance with CEQA and other applicable legal
requirements.
In preparing the restoration plans
required under this decision, LADWP should consider the
mitigation measures for potentially significant impacts
to cultural resources identified in the Draft EIR. (SWRCB
7, p. 3K-16.) The mitigation measures include a
literature search, completion of a cultural resources
reconnaissance, recording and evaluation of all cultural
resources in accordance with the CEQA guidelines, and
contacts with Native Americans and people familiar with
local history. The information developed during the field
reconnaissance work should be compiled in a written
report which can be used to identify sensitive cultural
resource areas and to develop restoration plans
accordingly.
Based on the results of the survey, the
significance evaluation of the identified cultural
resources and Native American consultation, a Cultural
Resources Treatment Plan (CRTP) should then be developed.
CEQA Guidelines (Appendix K) provide that the preferred
manner of treatment is the in situ preservation of
cultural resources. This can be accomplished through
project redesign (i.e., avoidance), through active
intervention such as capping with soil or rip-rapping
with stones, or through limiting access. The CRTP should
identify and elaborate on other treatment options as
noted in the Draft EIR in the event that preservation is
not feasible. (SWRCB 7, p. 3K-16.)
The CRTP should include provisions for
the protection of any resources of importance to the Mono
Basin Native American community and, if requested,
provide for access to resources and areas for traditional
uses. The CRTP must also include provisions for
unanticipated discoveries, such as human remains and
other archeological materials that could be discovered
during project required activities initiated after the
initial cultural resource reconnaissance. The CRTP must
delineate the requirements for archeological excavations
and require the preparation of research designs to guide
any required excavations or other types of data recovery
mitigation.
The CRTP must also include a monitoring
program to ensure the effectiveness of the treatment
plans that are implemented. This monitoring program
should provide for observation, at periodic intervals, of
the effectiveness of preservation/protection measures and
for guaging the status of impacts such as increased
recreational use of the Mono Basin area.
If federal lands (e.g., Inyo National
Forest) are included in the projected impact zone, any
cultural resource investigations conducted there would
have to satisfy federal laws and regulations in addition
to state statutes.
8.5.4 Conclusions Regarding Effects on
Cultural Resources
The limited cultural resources work which has been
conducted indicates that there has been a high level of
prehistoric and ethnographic use of riparian corridors
along streams in the Mono Basin. The legal requirement to
amend the LADWP licenses to require sufficient releases
to restore and maintain the pre-1941 fishery makes
infeasible any alternatives which do not risk possible
impacts to cultural resources from increased recreational
activity due to restored streamflows. Projects developed
as part of the restoration plans called for in this
decision have the potential to adversely impact cultural
resources. The specific types of impacts, alternatives
and mitigation measures associated with restoration
projects cannot be identified at this time. As part of
the restoration planning process, LADWP should be
required to take appropriate actions to protect cultural
resources in accordance with the provisions of the order
at the end of this decision. The SWRCB's determination of
what specific restoration measures will be required will
depend in part upon the effects of the proposed
activities on cultural resources.
8.6 Indirect Environmental Impacts of
Reduced Mono Basin Water Diversions
The record establishes that there will be sufficient
replacement water available to Los Angeles from other
sources to offset the reductions in water diversions from
the Mono Basin. (See Section 7.1.3.) The reduction in
Mono Basin water diversions will be offset by some
combination of increased use of local groundwater due to
a credit for water LADWP imports into the San Fernando
Valley, expanded water conservation measures, increased
water reclamation projects in Los Angeles, increased
purchases from Metropolitan Water District of Southern
California and, possibly, increased water provided from
other sources such as water transfers.
Obtaining additional water from some of
the alternative sources of supply may have indirect
adverse environmental impacts. The nature and extent of
those impacts will depend in large part upon which
sources of replacement water LADWP chooses to pursue.
Under present circumstances, it is too speculative for
the SWRCB to evaluate indirect impacts of LADWP obtaining
replacement water from other sources.
8.7 Other Environmental Impacts of
Amendment of LADWP Water Right Licenses
The EIR identified stream channel erosion due to high
flows in the four diverted streams as a potentially
significant impact of selecting the 6,390 feet
alternative (which is similar to the requirements
established in this decision). Limitations on high flows
which were proposed as mitigation measures can be
considered as part of the stream restoration plan. In the
absence of additional operational information, it is not
feasible for the SWRCB to specify precisely how high
flows should be handled at this time. The establishment
of water diversion criteria which will result in
increasing the water level at Mono Lake in order to
protect public trust resources is an overriding
consideration justifying adoption of this decision
despite potential stream erosion impacts of high flows.
The potentially harmful effect of high
flows on the fisheries in Rush Creek and Lee Vining Creek
will be partially mitigated by the ramping rates and
channel maintenance flows established in this decision.
It is not feasible to implement other potential
mitigation measures identified in the EIR pending
availability of additional information which will be
developed as part of the stream restoration plans. The
need to establish water diversion criteria which will
increase the water level at Mono Lake is an overriding
consideration justifying adoption of this decision
despite potential adverse impacts of high flows on fish
in the four diverted streams.
The increased instream flows and the
restrictions on Mono Basin water exports under this
decision could adversely impact recreation at Crowley
Lake and Grant Lake. The EIR suggests construction of a
substitute waterskiing course at Lake Crowley as a
mitigation measure. The EIR does not identify available
funding for a substitute waterskiing course, nor does the
record contain sufficient evidence regarding construction
of a substitute waterskiing course. Whatever benefits may
be associated with a waterskiing course, it is infeasible
for the SWRCB to require LADWP to construct a waterskiing
course as a condition of its water right licenses, and
the SWRCB itself has no funding for such projects.
Recreation at Grant Lake could be protected by
maintaining a water elevation at or above 7,111 feet
during the recreation season. This decision requires
LADWP to prepare a Grant Lake operations and management
plan which will consider recreational and other aspects
of Grant Lake operations. Pending completion of that
plan, it is not feasible for the SWRCB to establish
operations criteria for Grant Lake. The need to establish
the fishery protection flows and water diversion criteria
to protect other public trust resources are overriding
considerations which justify adoption of this decision
despite potential adverse impacts on recreation at
Crowley Lake and Grant Lake.
9.0 SUMMARY AND CONCLUSIONS
The City of Los Angeles' water
diversions from the Mono Basin were authorized over fifty
years ago when protection of environmental and public
trust resources was viewed very differently than today.
Los Angeles' export of water from the Mono Basin has
provided a large amount of high quality water for
municipal uses, but it has also caused extensive
environmental damage. In 1983, the California Supreme
Court ruled that the State Water Resources Control Board
has the authority to reexamine past water allocation
decisions and the responsibility to protect public trust
resources where feasible. Later decisions by the
California Court of Appeal emphasized the legal priority
attached to providing instream flows for fishery
protection.
Based on examination of the public trust
resources of the Mono Basin, consideration of the flows
needed for protection of fish, and consideration of the
impacts of this decision on the water available for
municipal use and power production, the SWRCB concludes
that the water right licenses of the City of Los Angeles
should be amended in several respects as discussed in
detail in previous sections of this decision. The
necessary license amendments include establishment of
minimum instream flows for protection of fish in the
streams from which LADWP diverts water, as well as
periodic higher flows for channel maintenance and
flushing purposes similar to what occurred under natural
conditions.
This decision also amends Los Angeles'
water right licenses to include specified water diversion
criteria which are intended to gradually restore the
average water elevation of Mono Lake to approximately
6,392 feet above mean sea level in order to protect
public trust resources at Mono Lake. Among other things,
the increased water level will protect nesting habitat
for California gulls and other migratory birds, maintain
the long-term productivity of Mono Lake brine shrimp and
brine fly populations, maintain public accessibility to
the most widely visited tufa sites in the Mono Lake Tufa
State Reserve, enhance the scenic aspects of the Mono
Basin, lead to compliance with water quality standards,
and reduce blowing dust in order to comply with federal
air quality standards.
The water diversion criteria will
significantly reduce the quantity of water which Los
Angeles can divert from the Mono Basin as compared to
pre-1989 conditions. Since 1989, however, a preliminary
injunction has prevented Los Angeles from diverting water
from the Mono Basin any time that the water level of Mono
Lake is below 6,377 feet. This decision continues the
prohibition on diversion at lake levels below 6,377 feet,
and specifies criteria under which Los Angeles can divert
water as the lake level rises. The rate at which the
water level of Mono Lake rises will depend in large part
upon future hydrology. Although the license amendments
restrict diversions from the Mono Basin, the evidence
shows that there are other sources of water reasonably
available to Los Angeles and that the amendments to Los
Angeles' licenses are feasible.
Finally, this decision requires specified
actions aimed at expediting the recovery of resources
which were degraded due to many years of little or no
flow in the four diverted streams. The decision requires
Los Angeles to consult with the Department of Fish and
Game and other designated parties, and to develop plans
for stream and waterfowl habitat restoration. The
specific restoration work that will be required will be
determined following the State Water Resources Control
Board's review of the restoration plans.
In summary, we believe that this decision
and the process by which it has been reached satisfy the
California Supreme Court's objective of taking "a
new and objective look at the water resources of the Mono
Basin." (National Audubon Society v. Superior
Court, 33 Cal.3d at 452, 189 Cal.Rptr. at 369.) The
requirements set forth in the order which follows are in
accord with the Court's mandate to protect public trust
resources where feasible and the mandate of the
California Constitution to maximize the reasonable and
beneficial use of California's limited water resources.
ORDER
IT IS HEREBY ORDERED that Water Right Licenses
10191 and 10192 are amended to include the following
conditions:
1. For protection of fish in the
specified streams, Licensee shall bypass flows below
Licensee's points of diversion equal to the flows
specified below or the streamflow at the point of
diversion, whichever is less. However, if necessary to
meet the dry year flow requirements on Rush Creek,
Licensee shall release water from storage at Grant Lake
Reservoir under the conditions specified below. The flows
provided under this requirement shall remain in the
stream channel and shall not be diverted for any other
use.
a. Lee Vining Creek
Dry Year Flow Requirements
April 1 through September 30
37 cfs
October 1 through March 31
25 cfs
Normal Year Flow Requirements
April 1 through September 30
54 cfs
October 1 through March 31
40 cfs
Wet Year Flow Requirements
April 1 through September 30
54 cfs
October 1 through March 31
40 cfs
b. Walker Creek
Flow Requirements for All Types of
Water Years
April 1 through September 30
6.0 cfs
October 1 through March 31
4.5 cfs
c. Parker Creek
Flow Requirements for All Types of
Water Years
April 1 through September 30
9.0 cfs
October 1 through March 31
6.0 cfs
d. Rush Creek
Dry Year Flow Requirements
April 1 through September 30
31 cfs
October 1 through March 31
36 cfs
Normal Year Flow Requirements
April 1 through September 30
47 cfs
October 1 through March 31
44 cfs
Wet year Flow Requirements
April 1 through September 30
68 cfs
October 1 through March 31
52 cfs
The dry year flow requirements in Rush
Creek shall be maintained, if necessary, by release of
stored water from Grant Lake until Grant Lake reaches a
volume of 11,500 acre-feet. If Grant Lake storage falls
below 11,500 acre-feet, the instream flow requirement
shall be the lesser of the inflow to Grant Lake from Rush
Creek or the specified dry year flow requirement.
For normal and wet hydrologic years, the
instream flow requirements shall be the requirements
specified above or the inflow to Grant Lake from Rush
Creek, whichever is less. If during normal and wet
hydrologic years the inflow to Grant Lake from Rush Creek
is less than the dry year flow requirements, then
Licensee shall release stored water to maintain the dry
year flow requirements until Grant Lake storage falls to
11,500 acre-feet or less.
2. Licensee shall provide channel
maintenance and flushing flows for each stream from which
water is diverted in accordance with the flows specified
below. In the event that the flows at the Licensee's
points of diversion on Lee Vining Creek, Walker Creek and
Parker Creek are insufficient to provide the channel
maintenance and flushing flow requirements, Licensee
shall bypass the highest flows which are expected to be
present at its points of diversion for the length of time
specified in the tables below, and shall notify as soon
as reasonably possible the Chief of the Division of Water
Rights of the reason that the normally applicable channel
maintenance and flushing flow requirements could not be
met. In addition, at times when Licensee is responsible
for the change in flow in any of the streams from which
water is diverted, Licensee shall adjust the rate of
change of flow so as not to exceed the "ramping
rate" specified below for each stream. Licensee is
not required to compensate for fluctuations in the flow
reaching Licensee's point of diversion. The specified
ramping rates shall be determined based on the percentage
of change in flow from the average flow over the
preceding 24 hours.
a. Lee Vining Creek
CHANNEL MAINTENANCE &
FLUSHING FLOW REQUIREMENTS LEE VINING CREEK
HYDROLOGIC
CONDITION
|
REQUIREMENT
|
DRY
YEAR
|
NO
REQUIREMENT
|
NORMAL
YEAR
|
160
CFS FOR A MINIMUM
OF 3 CONSECUTIVE DAYS
DURING MAY, JUNE OR JULY
|
WET
YEAR
|
160
CFS FOR 30
CONSECUTIVE DAYS
DURING MAY, JUNE OR JULY
|
RAMPING RATE - NOT TO
EXCEED 20% CHANGE DURING ASCENDING FLOW
AND 15% DURING DESCENDING FLOWS PER 24
HOURS
|
b. Walker Creek
CHANNEL MAINTENANCE AND
FLUSHING FLOWS FOR LOWER WALKER CREEK
HYDROLOGIC
CONDITION
|
REQUIREMENT
|
DRY
YEAR
|
NO
REQUIREMENT
|
NORMAL
YEAR
|
15
TO 30 CFS FOR
1 TO 4 CONSECUTIVE DAYS
BETWEEN MAY 1 AND JULY 31
|
WET
YEAR
|
15
TO 30 CFS FOR
1 TO 4 CONSECUTIVE DAYS
BETWEEN MAY 1 AND JULY 31
|
RAMPING RATE - NOT TO EXCEED
10% CHANGE IN STREAMFLOW PER 24 HOURS
|
c. Parker Creek
CHANNEL MAINTENANCE &
FLUSHING FLOWS FOR LOWER PARKER CREEK
HYDROLOGIC
CONDITION
|
REQUIREMENT
|
DRY
YEAR
|
NO
REQUIREMENT
|
NORMAL
YEAR
|
25
TO 40 CFS FOR
1 TO 4 CONSECUTIVE DAYS
BETWEEN MAY 1 AND JULY 31
|
WET
YEAR
|
25
TO 40 CFS FOR
1 TO 4 CONSECUTIVE DAYS
BETWEEN MAY 1 AND JULY 31
|
RAMPING RATE - NOT TO EXCEED A
10% CHANGE IN STREAMFLOW PER 24 HOURS
|
d. Rush Creek
CHANNEL MAINTENANCE &
FLUSHING FLOW REQUIREMENTS RUSH CREEK
HYDROLOGIC
CONDITION
|
REQUIREMENT
|
DRY
YEAR
|
NO
REQUIREMENT
|
DRY-NORMAL
YEAR
|
NO
REQUIREMENT
|
NORMAL
YEAR
|
200
CFS FOR 5 DAYS
|
WET-NORMAL
YEAR
|
300
CFS FOR 2 CONSECUTIVE DAYS
RAMP DOWN TO 200 CFS,
MAINTAIN 200 CFS FOR 10 DAYS
|
WET
YEAR
|
300
CFS FOR 2 CONSECUTIVE DAYS
RAMP DOWN TO 200 CFS,
MAINTAIN 200 CFS FOR 10 DAYS
|
RAMPING RATE - NOT TO EXCEED A
10% CHANGE IN STREAMFLOW PER 24 HOURS
|
Runoff
year definition: Dry 80-100%
exceedence (68.5% of average runoff)
Dry-Normal 60-80% exceedence (between 68.5% and 82.5% of
average runoff)
Normal 40-60% exceedence (between 82-5% and 107% of
average runoff)
Wet-Normal 20-40% exceedence (between 107% and 136.5% of
average runoff)
Wet 0-20% exceedence (greater than 136.5% of average
runoff)
The ramping requirement applies to changes in flow made
by LADWP. LADWP is not required to compensate for natural
fluctuations in flow.
3. For purposes of determining: (1)
applicable instream flows for protection of fish on Lee
Vining Creek and Rush Creek; and (2) channel maintenance
and flushing flow requirements on Lee Vining Creek,
Walker Creek, Parker Creek, and Rush Creek, the
hydrologic year type classification shall be determined
using projected unimpaired runoff for the runoff year
April 1 through March 31 as estimated using the LADWP
Runoff Forecast Model for the Mono Basin. The unimpaired
runoff is the sum of forecasts for the Lee Vining Creek,
Walker Creek, Parker Creek, and Rush Creek sub-basins.
Preliminary determinations of the runoff
classification shall be made by Licensee in February,
March, and April with the final determination made on or
about May 1. The preliminary determinations shall be
based on hydrologic conditions to date plus forecasts of
future runoff assuming median precipitation for the
remainder of the runoff year. Instream flow requirements
prior to the final determination in May shall be based on
the most recent runoff projection. Following issuance of
final determination in May, that hydrologic year
classification shall remain in effect until the
preliminary runoff determination made in April of the
next year. The hydrologic year type classification shall
be as follows:
Wet Hydrologic Conditions: Projected
runoff greater than 136.5% of average
Normal Hydrologic Conditions: Projected
runoff between 68.5% and 136.5% of average (inclusive)
Dry Hydrologic Conditions: Runoff less
than 68.5% of average
For purposes of determining the channel
maintenance and flushing flow requirements on Rush Creek,
the hydrologic year-type determination shall be in
accordance with the criteria specified in part
"d" of the preceding condition.
4. Licensee shall maintain continuous
instantaneous measuring devices at each point of
diversion which are satisfactory to the Chief of the
Division of Water Rights and which measure the streamflow
above the diversion facility and the flow immediately
below the diversion facility. Licensee shall maintain
detailed records from which the flow above and below the
diversion facility, and the quantity of water diverted
can be readily determined. Licensee shall report to the
Chief of the Division of Water Rights within 72 hours any
event when the flows required by this order are not met.
As soon as reasonably possible, Licensee shall provide an
explanation of why the required flows were not met.
5. Livestock grazing on Licensee's
property within the riparian corridors of Lee Vining
Creek, Walker Creek, Parker Creek, and Rush Creek,
downstream of points of diversion authorized under this
license, is prohibited for a minimum of ten years.
Grazing after that time shall be subject to approval of
the SWRCB or its Executive Director of a plan prepared by
Licensee following consultation with the Department of
Fish and Game and U.S. Forest Service.
6. In addition to the instream flow
requirements for fishery protection, channel maintenance
and flushing purposes, diversion of water under this
license is subject to the limitations specified below.
For purposes of determining the applicable water
diversion criteria, the water level of Mono Lake shall be
measured on April 1 of each year and the limitation on
water diversions shall apply for the one year period of
April 1 through March 31 of the succeeding year, except
as otherwise specified below. The water level shall be
measured at the LADWP gage near Lee Vining Creek or such
other gage as is approved by the Chief of the Division of
Water Rights.
a. Water diversion criteria applicable
until the water level of Mono Lake reaches 6,391 feet:
(1) Licensee shall not export any water
from the Mono Basin any time that the water level in Mono
Lake is below 6,377 feet above mean sea level, or any
time that the water level of Mono Lake is projected to
fall below 6,377 feet at any time during the runoff year
of April 1 through March 31.
(2) If the water level of Mono Lake is
expected to remain at or above 6,377 feet throughout the
runoff year of April 1 through March 31 of the succeeding
year based on Licensee's final May 1 runoff projections
and any subsequent runoff projections, then Licensee may
divert up to 4,500 acre-feet of water per year under the
terms of this license.
(3) If the water level of Mono Lake is at
or above 6,380 feet and below 6,391 feet, then Licensee
may divert up to 16,000 acre-feet of water per year under
the terms of this license.
(4) In the event that the water level of
Mono Lake has not reached an elevation of 6,391 feet by
September 28, 2014, the SWRCB will hold a hearing to
consider the condition of the lake and the surrounding
area, and will determine if any further revisions to this
license are appropriate.
b. Water diversion criteria applicable
after the water level of Mono Lake reaches 6,391 feet:
(1) Once the water level of Mono Lake has
reached an elevation of 6,391 feet, no diversions shall
be allowed any time that the water level falls below
6,388 feet.
(2) Once a water level of 6,391 feet has
been reached and the lake level has fallen below 6,391,
diversions by Licensee shall be limited to 10,000
acre-feet per year provided that the water level is at or
above 6,388 feet and less than 6,391 feet.
(3) When the water level of Mono Lake is
at or above 6,391 feet on April 1, Licensee may divert
all available water in excess of the amount needed to
maintain the required fishery protection flows and the
channel maintenance and flushing flows, up to the amounts
otherwise authorized under this license.
7. Licensee's combined rate of diversion
through the Mono Craters Tunnel under all bases of right
shall be regulated so that the sum of discharge from East
Portal and the natural flow in the Owens River at East
Portal do not exceed 250 cfs as measured directly
downstream of the East Portal discharge. Licensee shall
make releases to the upper Owens River at a relatively
stable rate consistent with operational limitations and
water availability. This standard shall be incorporated
into the Grant Lake operations and management plan to be
submitted as part of Licensee's stream restoration plan.
8. Licensee shall prepare and submit to
the SWRCB for approval a stream and stream channel
restoration plan and a waterfowl habitat restoration
plan, the objectives of which shall be to restore,
preserve, and protect the streams and fisheries in Rush
Creek, Lee Vining Creek, Walker Creek, and Parker Creek,
and to help mitigate for the loss of waterfowl habitat
due to the diversion of water under this license. The
plans shall include consideration of measures to promote
the restoration of the affected streams and lake-fringing
waterfowl habitat which are functionally linked to the
streamflows and lake levels specified in this order. The
restoration plans shall include elements for improving
instream habitat for maintaining fish in good condition.
These plans are subject to technical and financial
feasibility, reasonableness, and adequacy of the measures
proposed to achieve the stated objectives. The
restoration plans shall identify the specific projects to
be undertaken, the implementation schedule, the estimated
costs, the method of financing, and estimated water
requirements. The plans shall be prepared in accordance
with the requirements specified below:
a. The stream restoration plan shall make
recommendations on stream and stream channel restoration
including, but not limited to, the following elements:
(1) Instream habitat restoration measures
for Rush Creek;
(2) Rewatering of additional channels of
Rush Creek and Lee Vining Creek;
(3) Riparian vegetation restoration for
Rush Creek and Lee Vining Creek;
(4) A sediment bypass facility at
Licensee's diversion structure on Lee Vining Creek;
(5) Flood flow contingency measures;
(6) Limitations on streamcourse vehicular
access;
(7) Construction of a fish and sediment
bypass system around Licensee's diversion facilities on
Walker Creek and Parker Creek;
(8) Spawning gravel replacement programs
downstream of Licensee's points of diversion on Rush
Creek, Lee Vining Creek, Walker Creek and Parker Creek;
(9) Livestock grazing exclusions in the
riparian areas below Licensee's point of diversion on all
diverted streams after the period specified in Term 5 of
this order;
(10) Feasibility evaluation of installing
and maintaining fish screens at all points of diversion
from the streams, including irrigation diversions on
LADWP property.
(11) Grant Lake operations and management
plan.
b. The stream restoration and protection
requirements established in this order do not replace any
requirements established by the Superior Court for El
Dorado County in the context of granting interim relief
in the consolidated Mono Lake Water Rights Cases
(El Dorado County, Superior Court Coordinated Proceeding
Nos. 2284 and 2288). Licensee shall continue to
completion any and all work required pursuant to court
order, including implementation of any restoration plans
approved by the court, unless and until the court order
is dissolved and the Licensee obtains approval of the
SWRCB. In evaluating additional stream restoration work
to be included in the restoration plan required under the
terms of this order, Licensee shall consider the
restoration work undertaken pursuant to the direction of
the Superior Court. In addition, the Licensee shall
consider information which has been developed by the
Restoration Technical Committee and its consultants
pursuant to direction from the Superior Court, including
but not limited to planning documents finalized and
approved by January 1, 1995.
c. The waterfowl habitat restoration plan
shall make recommendations on waterfowl habitat
restoration measures and shall describe how any restored
waterfowl areas will be managed on an ongoing basis. The
plans shall focus on restoration measures in
lake-fringing wetland areas.
d. The stream restoration plan and the
waterfowl habitat restoration plan shall be subject to
the following requirements:
(1) The restoration plans shall be
consistent with the management regulations and statutes
governing the Mono Basin National Forest Scenic Area and
the Mono Lake State Tufa Reserve.
(2) The restoration plans shall identify
the specific projects to be undertaken, the
implementation schedule, the estimated costs, the method
of financing, and estimated water requirements.
(3) The restoration plans shall include
an inventory of existing conditions including a status
report on all restoration work undertaken pursuant to
direction of the El Dorado County Superior Court.
(4) The restoration plans shall include a
method for monitoring the results and progress of
proposed restoration projects. The monitoring proposal
shall identify how results of restoration activities will
be distinguished from naturally occurring changes and
shall propose criteria for determining when monitoring
may be terminated.
(5) Licensee shall be responsible for
compliance with all applicable state and federal statutes
governing environmental review of projects proposed in
the restoration plans. In developing the restoration
plans, Licensee shall emphasize measures that have
minimal potential for adverse environmental effects. The
time schedule specified in the restoration plans shall
include procedures for compliance with the California
Environmental Quality Act (Public Resources Code Section
21000, et seq.) and for obtaining all necessary permits
or governmental agency approvals.
e. Licensee shall prepare or contract for
the development of the plans identified in this order.
SWRCB staff will provide guidance in that development. In
developing the required restoration plans, Licensee shall
seek active input from the following parties: California
Department of Fish and Game, California State Lands
Commission, California Department of Parks and
Recreation, the United States Forest Service, the
National Audubon Society, the Mono Lake Committee, and
California Trout, Inc. It is not the intent of the SWRCB
that LADWP shall have any obligation to reimburse other
parties for costs they may incure in the restoration
planning process, except as otherwise required by law.
f. The restoration plans shall be
developed in accordance with the following schedule:
(1) Based on review of information
received from the agencies and parties designated in
paragraph 8e of this order, Licensee shall prepare a
draft scope of work for the restoration plans which
addresses each of the plan elements specified above. The
draft scope of work shall identify a time schedule within
which to prepare and implement the various elements of
the restoration plans. The draft scope of work shall be
submitted to the Chief of the Division of Water Rights by
February 1, 1995.
(2) By August 1, 1995, Licensee shall
complete draft restoration plans which Licensee shall
then make available to the parties designated in
paragraph 8e for a 60-day review and comment period.
(3) Following any revisions to the draft
plans made in response to comments from the designated
agencies and parties, Licensee shall prepare final
proposed restoration plans to be submitted to the SWRCB
for approval by November 30, 1995. The final proposed
restoration plans shall also be made available to the
parties designated in paragraph 8e above who may submit
comments on the proposed plans to the SWRCB by
December 31, 1995.
(4) The SWRCB will review the final
proposed restoration plans based primarily on the
following factors:
(a) adequacy of the
measures proposed to achieve restoration of the
fisheries, streams, stream channels, waterfowl habitat
and other public trust resources;
(b) technical and
financial feasibility; and
(c) reasonableness.
(5) Following review of the final
proposed restoration plans, the SWRCB will determine if
the plans are acceptable and will notify the Licensee of
its determination. If the SWRCB determines that a plan,
plans, or portions thereof, are not acceptable, then
Licensee shall submit a revised plan or plans in
accordance with direction from the SWRCB.
(6) If an environmental impact report is
required for any measures proposed in the restoration
plans or if revisions to the plans are necessary in order
to qualify for a mitigated negative declaration, then the
restoration plan or plans involved should be resubmitted
for SWRCB approval following completion of the
environmental impact report or negative declaration.
(7) Following the SWRCB's review of any
appropriate environmental documentation and approval of
the restoration plans, or portions thereof, Licensee
shall implement the specified restoration measures in
accordance with the time schedule set by the SWRCB.
Licensee shall submit semi-annual progress reports to the
Chief of the Division of Water Rights on the work
undertaken pursuant to the plans. The progress reports
shall include monitoring information on the status and
effectiveness of previously undertaken restoration
measures, and identification of appropriate revisions in
any cases where restoration has not been effective.
(8) The SWRCB shall have continuing
authority to require modification of restoration
activities as appropriate and to modify streamflow
requirements as necessary to implement restoration
activities. Modification of streamflow requirements may
reduce the amount of water available for export.
9. Licensee shall complete a cultural
resources investigation of all areas to be impacted by
the rewatering of the Mono tributaries, including all
areas subject to restoration and/or increased
recreational use. The investigation shall consist of a
literature and records search, a survey, the formal
recordation of all cultural resources identified, the
preparation of a written report documenting all research
and findings, and the identification of appropriate
mitigation measures in accordance with Appendix K of the
CEQA Guidelines. This investigation shall also include
appropriate consultation with the Mono Basin Native
American community to address their concerns. Appropriate
mitigation measures shall be proposed in the cultural
resources report to address any identified impacts to
contemporary traditional use of the Mono Basin area by
Native Americans. The report shall be submitted by August
1, 1995 to the Chief of the Division of Water Rights for
review and approval.
10. Licensee shall complete a Cultural
Resources Treatment Plan (CRTP) based on the findings and
recommendations in the written report on the cultural
resources investigations, the consultation with the
Native American community, and the comments received from
the review of the cultural resources document by the
SWRCB. The CRTP shall include provisions for the
appropriate treatment of all identified cultural
resources. The CRTP shall provide for access to resources
and locations deemed important to their traditional
lifeways by the Native American community. The CRTP shall
include provisions for unanticipated discoveries that
could be encountered during project activities authorized
subsequent to the completion of the cultural resources
document. The CRTP shall delineate the guidelines for
archeological excavations and require the preparation of
research designs prior to the initiation of any data
recovery programs. The CRTP shall also provide for a
monitoring program to ensure the effectiveness of
treatment measures and to gauge the impacts of the
increased recreational use of the Mono Lake tributaries.
The CRTP shall outline mitigation options to be
implemented if the monitoring indicates that impacts are
occurring as a result of project-related activities. The
CRTP shall be submitted to the Chief of the Division of
Water Rights for review and approval in conjunction with
the draft stream restoration and waterfowl restoration
plans and no later than November 30, 1995.
11. Upon request, Licensee shall make
copies of any and all documents (research designs,
interim reports, draft reports, final reports, flow data,
etc.) relating to provisions of this order available to
the Chief of the Division of Water Rights or his
designee.
12. Pursuant to California Water Code
Sections 100 and 275 and the common law public trust
doctrine, all rights and privileges under this license,
including method of diversion, method of use, and
quantity of water diverted, are subject to the continuing
authority of the State Water Resources Control Board in
accordance with law and in the interest of the public
welfare to protect public trust uses and to prevent
waste, unreasonable use, unreasonable method of use, or
unreasonable method of diversion of said water.
The continuing authority of the SWRCB may
be exercised by imposing specific requirements over and
above those contained in this license with a view to
eliminating waste of water and to meeting the reasonable
water requirements of licensee without unreasonable draft
on the source. Licensee may be required to implement a
water conservation plan, features of which may include
but not necessarily be limited to (1) reusing or
reclaiming the water allocated; (2) using water reclaimed
by another entity instead of all or part of the water
allocated; (3) restricting diversions so as to eliminate
agricultural tailwater or to reduce return flow;
(4) suppressing evaporation losses from water
surfaces; (5) controlling phreatophytic growth; and
(6) installing, maintaining, and operating efficient
water measuring devices to assure compliance with the
quantity limitations of this license and to determine
accurately water use as against reasonable water
requirements for the authorized project. No action will
be taken pursuant to this paragraph unless the SWRCB
determines, after notice to affected parties and
opportunity for hearing, that such specific requirements
are physically and financially feasible and are
appropriate to the particular situation.
The continuing authority of the SWRCB
also may be exercised by imposing further limitations on
the diversion and use of water by the Licensee in order
to protect public trust uses. No action will be taken
pursuant to this paragraph unless the SWRCB determines,
after notice to affected parties and opportunity for
hearing, that such action is consistent with California
Constitution Article X, Section 2; is consistent with the
public interest; and is necessary to preserve or restore
the uses protected by the public trust
CERTIFICATION
The undersigned, Administrative Assistant
to the Board, does hereby certify that the foregoing is a
full and correct copy of a decision duly and regularly
adopted at a meeting of the State Water Resources Control
Board held on September 28, 1994.
AYE:
John Caffrey
James M. Stubchaer
Marc Del Piero
Mary Jane Forster
John W. Brown
NO:
None.
ABSENT:
None.
ABSTAIN: None.
Maureen Marché
Administrative Assistant to the Board
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