1994 SWRCB Mono Lake Decision 1631 (text)

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.

HYDRO- LOGIC YEAR	DRY	MONTH	DFG	SWRCB	LADWP	LADWP REVISED	INTERIM
		APRIL	37	37	25	25	35
		MAY	37	37	25	30	35
		JUNE	37	37	25	35	35
		JULY	37	37	25	35	35
		AUGUST	37	37	25	30	35
		SEPTEMBER	37	37	25	20	35
		OCTOBER	25	25	15	20	25
		NOVEMBER	25	25	15	20	25
		DECEMBER	25	25	15	20	25
		JANUARY	25	25	15	20	25
		FEBRUARY	25	25	15	20	25
		MARCH	25	25	15	20	25
	NORMAL	APRIL	54	54	25	25	35
		MAY	54	54	25	30	35
		JUNE	54	54	25	35	35
		JULY	54	54	25	35	35
		AUGUST	54	54	25	30	35
		SEPTEMBER	54	54	25	25	35
		OCTOBER	40	40	15	20	25
		NOVEMBER	40	40	15	20	25
		DECEMBER	40	40	15	20	25
		JANUARY	40	40	15	20	25
		FEBRUARY	40	40	15	20	25
		MARCH	40	40	15	20	25
	WET	APRIL	54	54	25	25	35
		MAY	95	54	25	30	35
		JUNE	95	54	25	35	35
		JULY	95	54	25	35	35
		AUGUST	95	54	25	30	35
		SEPTEMBER	54	54	25	25	35
		OCTOBER	40	40	15	20	25
		NOVEMBER	40	40	15	20	25
		DECEMBER	40	40	15	20	25
		JANUARY	40	40	15	20	25
		FEBRUARY	40	40	15	20	25
		MARCH	40	40	15	20	25

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;

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:

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;

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;

(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.

* 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.

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 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