Proposal for Services;  Lake Merced Raise Water Level Assessment
EDAW, Inc.
17 July 2002
 

Introduction

The San Francisco Public Utilities Commission (SFPUC) proposes to raise the level of water in Lake Merced. It is divided into three parts: the North Lake (also usually divided into two parts), the South Lake and the smaller Impound Lake. The lake has no surface channel outlet. The lake is shallow, weakly stratified, and eutrophic. The lake is a potential municipal and domestic supply and primarily is a recreational amenity in San Francisco, providing boating, fishing, shoreline recreation, bird watching and visual opportunities. According to the San Francisco Bay Basin Plan, beneficial uses for Lake Merced include potential municipal and domestic water supply, cold freshwater habitat, warm freshwater habitat, and fish spawning.

The lake has a number of problems that have been the subject of some controversy. In recent years, the water level of the lake has dropped significantly. While the lake level once was 27 feet deep, today the depth has dropped to about 18 feet deep. This is generally attributed to changing land use (e.g., a reduction in surface inflow related to the urban development of the catchment and installation of a stormwater collection system) and water use management.

The lake is eutrophic and bluegreen algae problems are present year-round. Lake Merced (North Lake) has been proposed by the San Francisco Bay Regional Water Quality Control Board (RWQCB) for inclusion on the Clean Water Act 303 (d) list as a threatened water body due to low dissolved oxygen (DO) and elevated pH concentrations. The SFPUC has requested that CWA Sec. 303 (d) listing not occur.

The lake no longer supports as large a fishery as it once had. Lake Merced historically supported significant urban fishing opportunities for San Francisco and surrounding communities. However, due to falling lake levels, poor water quality has become an increasingly significant problem and the quality of the recreational fisheries have suffered a concomitant decline. The California Department of Fish and Game (CDFG) and lake concessionaires once stocked up to 250,000 rainbow trout per year (Bergstrom 2001), whereas now such numbers can no longer be supported by the lake and stocking has been reduced from those levels. In response, in January 2001, California Trout filed an appeal to the State Water Resources Control Board to require the SFPUC to take action to restore the vitality of the lake for the urban recreational fishery. California Trout petitioned the state to halt the decline in the water level and the associated worsening water quality that is affecting the urban sport fishery in the lake.

To correct these problems, the SFPUC would like to establish a higher water level in the lake while not impairing its ecological health. This could occur by a combination of managed surface discharges into the lake as well as reestablished groundwater inflow. Recently, San Francisco and Daly City officials signed a 50-year contract to use recycled water and storm water runoff to counteract the reduced lake levels linked to groundwater use. The contract commits Daly City and three golf courses to reduce groundwater pumping from the Westside Basin aquifer. Pat Martel, SFPUC General Manager, indicated to the press (March 15, 2002) that the long-term goal is to raise the lake level by seven to ten feet. San Francisco will sell water to Daly City in lieu of cutting its groundwater pumping.

The SFPUC has conducted some pilot tests to raise the water level in the lake. Concerns were raised about effects on nesting birds related to the rate at which the lake level would be raised. The SFPUC reached an agreement with CDFG and Audubon to discharge SFPUC water into the lake and raise the surface level within certain specified periods. This "operating agreement" is no longer in effect. A long-term solution remains to be fully identified and evaluated.

In this regard, requirements to raise the water level were modeled in assessments made by GeoResource Consultants (GRC) and Luhdorff & Scalmanini Consulting Engineers (L&S). These investigations found that raising the lake level and sustaining the elevation would be generally feasible. L&S noted some important limitations on the model, but the overall results appear generally defensible. Based on these assessments, for the interim condition (for up to three years), the source of water for raising the lake level would be SFPUC potable water discharged from existing SFPUC facilities. We assume that the operating agreement terms would no longer apply, but they may be considered in the evaluation. After the third year, the long-term source water would be either recycled water from the North San Mateo County Sanitation District (NSMCSD) and/or the City of San Francisco (discharge facilities remain to be identified), or from treated storm water from a joint venture of the City and NSMCSD (discharge facilities remain to be identified). CH2MHill has evaluated a number of alternatives for water supply to raise the lake level. They currently are evaluating use of treated stormwater at the Vista Grande facility. The amount of surface source water needed to raise the lake level in part is dependent on the amount of groundwater inflow that reestablishes itself as pumping drops off. Terms of a long-term operating agreement remain to be defined, based in part on the ecological impact criteria and results of the proposed study in this proposal.

The primary issues related to changing the water level occur in four topical areas:

Wetland habitat biological resources

Aquatic habitat biological resources

Water quality

Recreational opportunities

These topical areas are inter-linked and to some extent raising the lake level places some of these issues in conflict with one another. For example, it appears likely that lowering of the lake level in recent years has provided opportunity for wetlands to expand in area. This, in turn, has provided greater real or potential habitat for some sensitive wildlife species as well as other species that are common or even undesirable. In a sense, the greater extent of wetlands has resulted in more biodiversity at Lake Merced. At the same time, the quality and opportunity for aquatic resources and fisheries has been diminished. Raising the lake level may in effect shift the balance back again to greater benefit to the aquatic habitats and resource opportunities. This, in turn, could shift some of the recreational opportunities that are present (not by type, but by degree), e.g., sport fishing vs. bird watching. Effects on other environmental considerations, such as soil erosion and visual resources, need to be taken into account as well.

Objectives

Based on our discussions with SFPUC staff and our reading of materials supplied with by the SFPUC, the following represents EDAW’s understanding of the objectives and issues that form the basis of the proposed investigation. At present, the SFPUC’s proposal to raise the lake level is framed by a number of objectives that must be addressed to meet the study objectives. Briefly, these include the following.

The first objective is to determine the short-term impacts to aquatic and terrestrial habitats for the interim (Phase 1) program so that specific actions can be taken this autumn (2002) to raise the lake level. In its most simple form, this entails using the existing data and models to evaluate the effects of the Phase 1 project. As noted, we will assume the existing operating agreement no longer applies as an operational limitation. We will assume a water source from the SFPUC for at least one year and up to three years. The objective of Phase 1 this program would be to have a project that could be supported either by a CEQA categorical exemption or a Mitigated Negative Declaration that would be adopted by the Commission in autumn.

The second objective is to develop a plan (Phase 2) that is comprehensive and long-term in its outlook, identifies the environmental, regulatory, and operational issues that would need consideration and definition in order to implement the use of recycled water and/or treated stormwater as source water to raise and maintain lake level. This alternatives analysis of source waters may include environmental, engineering, cost, logistical and political/public acceptability considerations.

• Changing the water level in Lake Merced may require the need to comply with a number of regulatory requirements. These are largely expected to relate to sensitive biological resources, water quality and City of San Francisco policies. Regulatory requirements related to the San Mateo County facilities also may need to be addressed if it would provide a supply to the lake. Identification and implementation of the processes for these regulatory requirements is a key objective of the scope of work.
• Because Lake Merced is a popular recreational facility, it is in the public eye. The proposal to raise the lake level was highly publicized in the news media (e.g., S.F. Chronicle, March 16, 2002). While support for the project appears to run high, proposed alteration of the lake level is likely to generate comment from elected officials, city staff, the public and many stakeholder groups are likely to be involved. Undoubtedly, special interest groups like California Trout will be supportive but also will carefully scrutinize the project and the impact evaluation. Other groups, such as Audubon, while possibly supportive of the raised water levels, may focus on impacts to sensitive habitat and wildlife species. San Francisco Recreation and Parks have been actively involved in the management of recreational and natural resource issues at the lake. There may be a trade-off between benefits and impacts to different resources. Part of EDAW’s scope of services addresses public outreach. The objective would be to obtain as high a degree of acceptability as possible for the project from regulatory agencies and key stakeholders in order to prevent further delays or litigation. While highly vocal stakeholders often receive special consideration by decision-makers, it is important to recognize the broad range of viewpoints surrounding the issues in a public outreach program. The SFPUC undoubtedly will want to lead the public outreach program, but support will be needed for presentations and use of consultant staff as an information resource.
• Lastly, the SFPUC staff has stated its desire to carry out the requested services so that the SFPUC can approve the project by early autumn 2002. This objective necessitates a commitment of the EDAW team and SFPUC staff to develop a well-thought out, fully integrated and rapidly implemented work program. EDAW’s team and its approach are oriented to meeting the schedule and all the objectives. Our approach to these goals follows.


GENERAL APPROACH

The EDAW+T&R team’s scope of services has been fashioned in response to our understanding of the technical issues and the needs and schedule requirements of the SFPUC. On the technical side, the fundamental questions are focused on what impacts a rise in lake level will have on the biological and other resources at Lake Merced. The consideration of the impacts, in turn, will serve as the basis for developing the plan for raising the lake surface level. The evaluation of the impacts on biological resources is tied to other considerations, notably hydrology and water quality. The related CEQA review and permitting requirements also entail consideration and evaluation of a wider spectrum of resource issues. The team is comprised of individuals with the full range of expertise needed to address all the issues likely to be encountered in this investigation.

On the schedule side, the team recognizes the urgency of developing a Phase 1 plan that can be taken to the Commission in early autumn. To meet the autumn schedule, the Phase 1 project further may be defined by establishing criteria that will allow the Phase 1 project to proceed with minimal environmental review requirements, that is, either a CEQA categorical exemption or a Mitigated Negative Declaration (time does not allow for an EIR to be processed). Thus, in its most simple form, the task is to identify how various inundation areas and depths may affect the lake’s resources given assumed water supply inputs to the lake and from that analysis determine how much inundation can occur without significant consequences that trigger lengthy regulatory and environmental review processes.

The issues of concern for the Phase 1 project focus on the wetland habitat fringing the lake and the wildlife species that inhabit them. Impacts on the lake aquatic ecosystem probably are not significant (and likely are beneficial) given the information that has been developed to date on water quality and aquatic resources. What is less clear is the potential effect, if any, that raising the lake would have on displacement or loss of the sensitive habitats and species.

The driving question here is to define what level of impact within that range can be allowed to occur before it is deemed significant under the existing operational constraints in the agreements with CDFG and Audubon. Significance in this case could be interpreted to mean impact that would be substantial enough to result in a determination that "take" under federal and state ESAs could occur or result in unavoidable significant impact under CEQA.

In contrast, the Phase 2 long-term plan remains open to further evaluation and our interpretation is that a more comprehensive strategy will be required. We will need to test whether raising the lake level up from 4 to 6 feet (and perhaps 8 feet) in the long-term would result in loss of some wetland habitat. The amount of loss and its significance in Phase 2 requires consideration and integration of a wider spectrum of issues, water source inputs, and models. Additionally, the Phase 2 project introduces the aspect of a change in water quality, bringing not only the fringe wetland issues into the spotlight, but also the aquatic ecosystem as related to a possible change in nutrient loading.

At present, much less is known to the team about the alternative water sources and their quality characteristics, the operational requirements for using other water sources, the adequacy of the existing models to address these, cost, public acceptance etc. Significant data gaps may be present that might hinder selection among the alternatives on an equal playing field. For example, new water quality and ecological models likely will be needed to address different nutrient input into the lake from new water sources (recycled and treated storm water). In this regard, the analysis must address effects in relation to the beneficial uses. The RFP specifies that for the analysis we will assume that the beneficial uses of Lake Merced will not be changed from their current designation. Having a water balance model of the lake may be critical to understanding how the lake may react to induced discharges and increased groundwater inflow. At the time of this proposal, it is to early to tell what data gaps may exist and how they may constrain the alternatives analysis in Phase 2. This is information that the team would develop as part of the Task 1 data gaps analysis. In any event, the team’s goal will be to use the available information to the maximum extent possible to develop a "road map" for the creation and implementation of a conceptual long-term project.

Recognizing the overall approach that we have outlined, we present in the following section the team’s specific plan for Phase 1 and Phase 2.
 

Phase 1 – Short-term Water Addition Project

The primary goal of Phase 1 is to determine the amount of water that can be added, without significant environmental impact, to raise and maintain lake level beginning in Autumn 2002 (and continuing for three years until Hetch Hetchy water is no longer available as a source for this purpose). We will rely primarily on baseline aquatic, terrestrial, aerial surveys, and existing information to describe the current and historical conditions at Lake Merced. A conceptual modeling approach will be used to evaluate the effects of various lake level management scenarios on lake beneficial uses and key species of concern.
 

Task 1 - Workplan Development


The development of a work plan includes the following subtasks:

1. Review available literature and existing survey data
2. Develop draft work plan
3. Conduct/attend meetings and/or interviews with City staff and local experts
4. Identify important data gaps
5. Revise work plan in response to feedback from City and other stakeholders
Deliverable: Draft and Finalized Work Plan

Approach

The EDAW team will meet with the staff to refine the overall work program presented herein. The review of the extensive existing information about Lake Merced will be a key task. These include baseline aquatic, terrestrial, and aerial surveys. Since the extent and quality of the existing data and information are not completely known to the project team, this task forms the foundation of the investigation. During meetings with SF PUC staff, issues pertaining to the adequacy of mapping, the adequacy of existing models, the type of CEQA review, and coordination with MEA will be resolved.

Some of the important issues to be resolved include the following:

• Is topographic mapping adequate? It is important to have good up to date topographic mapping with a contour interval that is sensitive to the environmental analysis. We assume the topographic base is available and up to date. If mapping is not available, to fix this key data gap, Talavera & Richardson will need to create a new base map interpolating contour lines.
• What is the status of the existing water balance model? Can alternatives be identified and evaluated adequately with the existing model? These may be especially critical questions to resolve for Phase 2.
• What is the assumed baseline level of the lake upon which the analysis is based?
• Will the alternatives be developed with public/regulatory agency input? Is the public outreach program primarily an information dissemination program or is public input being solicited as part of the decision-making process?
• How will the CEQA review requirements be coordinated with MEA? What assumptions can be made about the CEQA review document? As noted, at this point we assume that SFPUC will need a categorical exemption or a Mitigated Negative Declaration if an action is to be taken by autumn.
• What are the critical information data gaps for the resources in question and how can these be resolved quickly?


Subtask 1.1 - Literature and Data Review

Wetlands and Terrestrial Resources

EDAW biologists will compile and review background information regarding biological resources within the Lake Merced project area. The primary source of information will be the Lake Merced 1998 Baseline Natural Resources Inventory prepared by Trihey and Associates. We assume that relevant sources of natural resources information cited in the Trihey and Associates report will also be provided to EDAW for review such as the Entrix report, information from Kurz and Murphy, and relevant fisheries reports. Any other available and relevant reports will also be reviewed. We understand that San Francisco Recreation and Parks has developed new information and mapping. We will contact the Significant Natural Areas Program manager to obtain information and integrate it into the analysis. We assume this will not require substantial data reduction. The local Audubon Society, Cal Trout, the lake concessionaires, staff of the San Francisco’s Significant Natural Areas Program, other organizations, and knowledgeable individuals will be contacted to update the natural resource information of Lake Merced. In addition, queries will be made of the California Department of Fish and Game’s (CDFG) California Natural Diversity Database (CNDDB) and the California Native Plant Society’s (CNPS) Electronic Inventory of Rare and Endangered Vascular Plants to determine if there are any additional special-status species that could occur at Lake Merced. We assume that this information is readily available in report format. Any need to analyze raw data to provide critical information will be the subject of a contract amendment. After compiling the information, data gaps will be identified and additional field surveys will be recommended if deemed necessary.

Hydrology

HydroConsult (HCE) will review the available information on the hydrologic system of Lake Merced, including the Luhdorf and Scalmanini report. The review will include SFPUC data on historic lake levels and the relationship to precipitation receipt. An objective will be to identify both historic lake levels and the relationship to inflow sources and outflow that affect the lake level. HC will review the existing hydrological model for Lake Merced. New modeling is not proposed as part of this scope of work. The analysis is directed to the following inputs:

• Monthly lake inflows from local runoff, overflow from Vista Grande Canal, and water additions;
• Stage/storage curve (lake volume at different water levels)
• Hydraulic interaction between the north, south and impound lakes
• Interaction with the Westside Basin aquifer (to the extent that it is already quantified)
• Estimates of monthly water availability in the short term and long-term.


Aquatic Resources

Available existing survey data and literature pertaining to Lake Merced will be reviewed and summarized. Hagar Environmental Science (HES) will work with the project team to identify sources of relevant information. Potential sources of information include reports and summaries of California Department of Fish and Game monitoring activities, electrofishing surveys, and any special studies including aquatic habitat inventories, fish population censuses, migration/spawning surveys, and other sources. Local experts, such as CalTrout and lake concessionaires, will also be contacted. It is assumed that information will be available in summary or report form and that entry, analyses, or evaluation of raw data by HES will not be required. If significant sources of potentially useful unreduced data are identified, HES will submit a proposed contract amendment for additional work to be completed at additional cost.

Based on the information gathered, data gaps will be identified and the need for additional field surveys will be recommended, if deemed necessary.

Water Quality

Merritt Smith Consulting (MSC) will summarize the analysis results described in Water Quality Investigation and Assessment Report: Potential Water Quality Effects In Lake Merced From Enhanced Ammonia Inputs (October 2001). This report describes the results of a detailed analysis of water quality impacts of several water discharge scenarios to Lake Merced. Depending on how the Phase 1 operating condition is defined (in terms of flow, frequency, and quality of discharge), their impact is expected to have already been evaluated in or be similar to alternatives evaluated in the October 2001 report. The October 2001 analysis (and the knowledge of Lake Merced gained by conducting the analysis) will facilitate evaluation of the Phase I operating condition impacts directly on algal growth nutrients and algae, and indirectly on dissolved oxygen, water depth and temperature.

Other Information Review

EDAW will review the available information on other resources and issues, such as soils (from the CDM-Trihey & Assoc, 1999 Report), land use and plans for the area, pertinent policies in the Comprehensive Plan Elements, recreational use data, SFPUC plans and programs and other information of relevance.

Subtask 1.2 - Develop Draft Work Plan

After reviewing the available information, the team will prepare a draft work plan for review by SFPUC staff. The plan will lay out each task, a schedule for its completion, and the related deliverable. Critical path tasks and subtasks will be identified.

As part of this subtask, the team will assist in the identification of the near- and long-term goals and objectives for the project. The team and City will develop the overall strategy. EDAW, HES and MSC will provide environmental input and HCE will provide engineering input with regard to the needs to support the overall strategy. The team will provide a detailed work plan for both environmental and engineering support of the alternatives evaluation to be performed as part of Task 3 for both the interim (Phase 1) and long-term (Phase 2) project.

Subtask 1.3 - Meetings

Key members of the EDAW+T&R team will attend a kick-off coordination meeting with SFPUC staff. This meeting will serve to establish an information exchange, set protocols for communications and information management, discuss project goals and general approaches upon which to base the work plan.

Team members will set up meetings with SFPUC staff to conduct interviews and receive information as needed. This may include, for example, a meeting with staff on the chloramination program and de-chlorination development program.

A meeting will be scheduled to meet with key stakeholders and receive their input on the issues and suggestions for approaches to the evaluation.

A meeting will be scheduled to present and discuss the draft work plan.

A meeting will be scheduled to discuss the SFPUC’s and stakeholders comments on the draft work plan.

EDAW will prepare summaries of each of the meetings.

Subtask 1.4 - Identify important data gaps for further investigation

Following the literature review and development of project goals, the team will identify significant data gaps that could affect the evaluation of alternatives. We will specify what information is lacking and its significance, methods to fill the gap, and a schedule and cost. For Phase 1, we assume that additional data will not be required beyond that specified in this proposal.

Subtask 1.5 Revise work plan

As noted, following receipt of the comments on the draft work plan, the team will make revisions and submit the final work plan to the SFPUC. We will work with City staff to resolve any differences in opinion of the reviewers regarding the substance of the work plan. The resolution of the issues will be documented separately or as an appendix to the work plan.

Task 2 - Baseline Field Surveys (Optional)

The RFP indicates the potential need to "supplement existing information, if necessary, with new baseline field surveys focused on data needed for analysis of proposed alternatives and providing a baseline for future monitoring."

Aquatic Surveys (stratified by lake and wetland habitat zones)

• Phytoplankton and zooplankton
• Benthic invertebrates
• Fish
• Physical and Chemical Water Quality profiles.
Wetland & Terrestrial Surveys
• Validate existing vegetation mapping [subtask 2.1]
• Belt transects to measure percent cover by plant species vs. topographic position (with a focus on wetland and riparian vegetation) [subtask 2.2]
• Bird, mammal, reptile and amphibian utilization by vegetation / cover types and topographic zonation [subtask 2.3]
• GIS analysis to look at general spatial patterns, and to provide a basis for extrapolating from site-specific vegetation transect and wildlife survey data to the full project site [subtask 2.4]
• Conduct focused surveys, if needed, for special status species in areas that might be affected by proposed lake level changes [subtask 2.5]
Deliverables: GIS Topographic Overlays and Technical Memorandum

Approach for Task 2 Baseline Field Surveys – Aquatic Surveys

We assume that an evaluation of lake aquatic resources could be conducted using existing information about the aquatic resources, and the physical and chemical water quality conditions. Existing literature will be reviewed in Task 1 and if critical gaps in the data are then noted, additional fieldwork will be proposed. This fieldwork could entail surveys of phytoplankton and zooplankton , benthic invertebrates, and fish to determine species composition and abundance. In addition, data on the physical and chemical characteristics will be correlated with the data on plankton, benthic invertebrates and fish.

At this time, no additional lake and water quality surveys are proposed. If the Task 1 data review identifies significant information gaps, the specific additional survey requirements would be identified at that time as appropriate.

Approach for Task 2 Baseline Field Surveys – Wetland and Terrestrial Surveys

A biological analysis including mapping was completed by Trihey and Associates in 1998. More recent information has been developed by San Francisco Recreation and Parks. The extent of the bulrush and willow vegetation types could have changed since that time. The RFP recognizes the potential need to supplement existing information, if necessary, with new baseline field surveys focused on data needed for analysis of proposed alternatives and providing a baseline for future monitoring.

In contrast to the aquatic surveys discussed above, the wetland and terrestrial environment is likely to have changed since the report by Trihey and Associates in 1998. However, the degree of change is not expected to be large. In addition, in order to establish an adequate monitoring regime to assess effects of hydrologic change, baseline surveys are necessary. Because of the possibility of change of wetland extent, field surveys are important to quantify impacts to the existing vegetation types.

The following approaches address each of the subtasks in the RFP. The subtasks are described below.

Subtask 2.1 - Validate Existing Vegetation Mapping

An EDAW botanist will conduct a field verification of existing vegetation maps. The validation will be done by comparing the observed vegetation with the vegetation map prepared in the 1999 Trihey & Associates report and the more recent mapping by SF Recreation and Parks Significant Natural Areas Program. The boundaries of the different vegetation types will be verified during fieldwork. At this time, we have no reason to believe that vegetation cover would have changed substantially since 1998 when the Trihey & Assoc. surveys were made. In the event that EDAW’s biologists identify notable differences in the vegetation cover and the mapped information, then it may be necessary to re-do the mapping in those areas. For purposes of this task, we assume that new aerial photography will not be needed. This proposal does not include new photography and it would not be undertaken unless it is deemed necessary.

Subtask 2.2 - Belt Transects

Permanent transects will be established to record the change in the vegetation as the level of the water rises. These transects could be surveyed yearly. Each point along the transects will have a known elevation. This will allow us to extrapolate change in vegetation to areas outside of the transects based on elevation.

The transects would run perpendicular to the topographic gradient leading to each of the separate lakes of Lake Merced. The transects would be perpendicular to the shoreline and run from upland areas to the lower extent of wetland vegetation. The belt transects would be at least 3 feet wide and the boundaries between the vegetation types would be mapped on the transects. Locational data will be recorded using GPS technology.

Transects would be established in each of the three lakes (North, South, and Impound lakes, including the northeast and northwest portion of North Lake. Because depth of inundation affects the distribution of the wetland vegetation types, the transects will be established in areas with shallow slopes, steep slopes, and intermediate slopes.

Data collected will include the cover of each of the species in a particular portion of the transects and depth. Collecting this type of data will allow us to correlate vegetation with depth and slope steepness. (Steepness will be determined by using the existing topographic map). As the water level rises, we will be able to predict the change in the vegetation. In order to get the most accurate information regarding elevational change of the wetland vegetation (with increase in water level) a team of surveyors will measure the depth at each of the vegetation boundaries along the established transects. EDAW botanists will locate the survey points and Talavera and Richardson will coordinate the survey effort.

Data from two transects will be gathered for each of the three slope steepness categories from each lake. A minimum of two transects is necessary to be able to verify that the vegetation types occur at the same level for a particular category of slope steepness. Data will be collected from more than two transects for each of the three slope steepness categories if there is high variability. A minimum of 6 transects (two transects for each of the three slope steepness categories) will be collected from each of the following lakes that comprise Lake Merced: northeast lake, northwest lake, South Lake and Impound Lake.

It is important to gather the transect data from representative areas from each of the lakes. It is also important to take the data from different slopes in order to determine how the vegetation changes as water level rises. Slope steepness may affect cover of different wetland vegetation types. Taking data from a variety of points to encompass the variability of the response to change of the level of the lake will allow us to make the most accurate extrapolation of vegetational change.

Subtask 2.3 - Bird, Mammal, Reptile, and Amphibian Utilization

Although Lake Merced is known to provide habitat for a number of bird species, the lake’s urban surroundings are expected to limit the diversity of more sedentary wildlife, including reptiles, amphibians, and mammals. Therefore, it is anticipated that existing information, data collected during vegetation transects, and field assessment of wildlife habitat suitability would be sufficient to predict what non-focal wildlife species would be associated with the different vegetation types and which species could be affected by changes in lake level. It is assumed that existing information on bird utilization of habitats at Lake Merced and field assessment of habitat suitability will also be adequate to predict species distribution and potential effects of lake level changes. As a result, standardized baseline wildlife surveys are not included in this scope of work. If it is determined that such surveys are required, these services could be provided under an amendment to this scope of work.

Subtask 2.4 - GIS Analysis

GIS will be used to demonstrate results of vegetation mapping, vegetation transects, and focused surveys. It is assumed that existing vegetation layers will be provided to the team and that these layers are compatible with Talavera & Richardson’s GIS software. As T&R has worked previously for the SFPUC, we believe there is no incompatibility of the platforms and software.

Vegetation communities and locations of suitable habitat for focal species and documented occurrences of these species will be mapped as layers in the GIS. Results from vegetation transects and focused surveys will be provided in a database that is linked to the spatial data to allow for extrapolation of information from specific locations to the entire project area. This will be particularly useful in extrapolating from the vegetation and elevation data from the transects to model vegetation change in response to rising water levels.

Subtask 2.5 - Focused Surveys

An EDAW wildlife biologist and an EDAW botanist will consult with SFPUC personnel and local natural resource experts to develop a list of species for which focused surveys will be conducted. This would include special-status species, and may include other species of local interest and invasive species of management concern that have potential to be affected by changes in lake level. Based on EDAW’s current knowledge of the project area and its associated resources, focused surveys are expected to be warranted for San Francisco lessingia, San Francisco Bay spineflower, Kellogg’s horkelia, San Francisco owl’s-clover, San Francisco garter snake, California red-legged frog, western pond turtle, and saltmarsh common yellowthroat. Although Trihey and Associates indicate San Francisco garter snake and California red-legged frog are not expected to occur in the lake, focused surveys have not been conducted to confirm absence, and such confirmation of presence or absence is recommended in order to facilitate future environmental impact assessment and permitting processes. Focused survey efforts will be concentrated within the area surrounding Lake Merced that would be subject to inundation or otherwise affected by increased lake levels. Focused surveys will be conducted by EDAW wildlife biologists and botanists. For these surveys, it is not anticipated that any handling of species will be required. In the event that handling proves necessary, EDAW biologists are approved for each sensitive species except San Francisco garter snake. While unlikely, should a possible San Francisco garter snake be identified, then an additional survey conducted by specialists, Karen Swain or Sam McGuiness, would have to be carried out (Surveys by these specialists are not included in our scope or budget at this time.)

Technical Memorandum

A technical memorandum will be prepared that provides a summary of existing biological resources information and results of additional biological surveys and GIS analysis. The report will present and discuss results of vegetation map verification, vegetation transects, focused surveys, and GIS analysis. Potential impacts to these biological resources from changes in lake level will also be described and evaluated.

Task 3 - Develop a conceptual model

In this task, EDAW will develop a conceptual model using GIS topographical overlays to identify areas of inundation as a result of rising lake level as well as assess the feasibility and timing required to re-establish lake levels of 2, 4, 6 and 9 feet higher than present. This assessment will use only previously developed information including the Luhdorff & Scalmanini evaluation, any additional modeling evaluations prepared by City, available hydrologic and bathymetric data for the lake, potential regulatory restrictions, based on EDAW’s initial contacts with Department of Fish and Game, and information provided by SFPUC regarding available system capacity and facilities planned for deliveries.

The following subtasks will be included in Task 3:

1. Develop a conceptual model of lake level and hydroperiod (e.g., timing, depth, frequency and duration of inundation) interactions
2. Correlate historical and current vegetation with hydrologic (e.g., lake levels, hydroperiod) and topographic conditions
Deliverables: GIS Topographic Overlays and Technical memorandum

Approach for Subtask 3.1

The lake level has changed during historic times due to natural and human induced events. Analysis of the below subject areas will help the City determine how rapidly and how high to raise the level of the lake and which water source would be most appropriate.

• HCE will define quantity, quality and timing of short-term deliveries of potable water from the SFPUC system. The evaluation will focus on possible lake level increases above the assumed base level elevation that could be achieved with a program similar to SFPUC’s 1997-2001 program of lake augmentation, with planned implementation in Fall 2002.

• The recently completed evaluation by Luhdorff & Scalmanini (L&S) calculates the time required to fill the lake to target levels 2, 4, 6 and 9 feet above current conditions. This study takes into account potential constraints in water deliveries due to available capacity in the SFPUC system. It did not assess potential delivery constraints due to regulatory restrictions or environmental constraints on deliveries.

• We will review the model to be used by City for analysis of water levels, assuming that the City will provide information on past modeling. No new modeling is included at this time.


Approach for Subtask 3.2

Once EDAW has verified the vegetation mapping of the margins of Lake Merced and once the data from the transects have been collected, we will determine the effect on sensitive biological resources of increasing the level of Lake Merced. We will have estimates of the location of the different vegetation types in relation to the topographic and hydrologic gradients. Through a GIS analysis, as the height of the water level increases, the vegetation response can be modeled.

Task 4 - Assess environmental impacts

In this task, we will assess environmental impacts of increased water levels on aquatic and terrestrial habitats, water quality, and beneficial uses including recreational uses. Impacts will be calculated by using the models developed in Task 3 for 4 different levels. These levels are 2, 4, 6, and 9 feet above the April 1, 2002 lake level. The 9-foot level represents the 27-foot lake elevation that is considered the original average lake level. We will identify six indicator species. To select these species, EDAW biologists will contact CDFG and SF Recreation and Parks for input on desired focal species.

Aquatic Biology

The impact analysis will consider changes in water quantity (e.g., lake surface level, lake strata) to evaluate changes or shifts of the habitats of key species. This task will involve close coordination with and rely upon the hydrologic and water quality modeling task. Effects to existing and potential beneficial uses of fishery resources will be determined largely through projected changes in water quality conditions.

Terrestrial Biology

The effect of lake level on wetland vegetation, terrestrial vegetation, birds nesting in wetland and affected upland vegetation, and special-status species will be assessed. The results of the optional field surveys will be used for the impact analysis. An example of a species that might be affected is the salt marsh common yellowthroat that nests in the wetland vegetation at Lake Merced. A reduction of its bulrush habitat could result in a reduction in the number of nesting birds at Lake Merced. A map can be generated of the historical vegetation of Lake Merced, when the water level was higher. Confirmation with historical photography if available is desirable. The map of the historical vegetation can be compared to the map of the current vegetation. The historic habitat conditions for these species will be discussed.

A key element of this task will be the identification of impact significance criteria. Specifically, we will identify the threshold at which impact to habitats and the focal species may result in substantial effects on them and/or induce the need for lengthy regulatory reviews and permitting. The thresholds will relate both to direct losses of habitat related to the amount and rate of habitat change induced by changes in lake level and indirect effects induced by alteration of environmental quality (e.g., water quality, increased recreation access to sensitive habitat, etc.). This assessment will be based both on predictive ecological models as well as qualitative evaluation of potential environmental changes and uses.

Water Quality

Merritt-Smith Consultants will address the effects of the increases of the water level on water quality. These impacts are largely assumed to be beneficial. The effect of the different lake levels will be examined for algal growth, nutrients, dissolved oxygen, and temperature. This analysis will utilize the results described by Luhdorff & Scalmanini in Assessment of Water Addition Scenarios Lake Merced (May 20021) and Water Quality Investigation and Assessment Report: Potential Water Quality Effects In Lake Merced From Enhanced Ammonia Inputs (October 2001). These reports provide a detailed analysis of water supply feasibility and hydroperiod and water quality impacts of several scenarios of water discharge to Lake Merced. The October 2001 analysis (and the knowledge of Lake Merced gained by conducting the analysis) will facilitate evaluation of the impacts directly on algal growth, nutrient concentration dissolved oxygen, and temperature. MSC also will identify and evaluate any water quality issues related to materials that may be inundated by a raised lake level, e.g., the clay pigeon wastes at the Rod and Gun Club.

Coordination will occur between the water quality analyses, the aquatic biology analysis, and the hydrological analysis.

Hydrological Modeling

The general hydrology of Lake Merced will be discussed regarding relationships between lake level, rate of outflow, and lake nutrient concentrations. Coordination will occur between HCE and MSC pertaining to water quality issues.

Other

Impacts on recreational facilities and uses, including existing shoreline uses and shoreline management activities, etc. will be assessed.

Task 5 - Develop a technical memorandum

In this technical memorandum, EDAW will:

• Describe the results of reviews and analyses conducted in Tasks 3 and 4.
• Provide baseline aquatic and terrestrial habitat data
• Identify potentially important habitat areas
• Compare past, present, and proposed future conditions
• Compare the impacts of different water-level scenarios (project alternatives) based on affected habitat
• Discuss potential impacts on existing and potential beneficial uses


Deliverable: Draft and Final Technical Memorandum

Task 6 – Develop an in-field monitoring program

This task entails developing a monitoring program to monitor impacts of increasing the level of Lake Merced. The monitoring methodology will be based on the transects established as part of Task 2. The boundaries between different wetland vegetation types and the adjacent upland vegetation are dependent of the water gradient which is affected by the water level. As the water level changes, the gradient and the location of the vegetation boundaries will change. This task will determine the frequency of monitoring.

In addition to monitoring the location of the vegetation boundaries that are affected by changing water levels, we will monitor the effect of changing water levels on special-status species. This monitoring may be especially important for the special-status salt marsh common yellowthroat because it nests at Lake Merced. The results of our surveys in Task 2 can be compared to results of monitoring visits after the level of Lake Merced has changed.

Deliverable: Technical Memorandum describing the methodology and procedure for in-field monitoring and reporting.

Task 7 – Draft the required CEQA document

EDAW will work with SFPUC and MEA staff to identify whether a categorical exemption can be obtained for the Phase 1project. If not, we will prepare an Initial Study of Significance (IS) following CEQA Guidelines and MEA preference upon which a Mitigated Negative Declaration (MND) can be developed. EDAW will prepare a Draft IS and MND.

This task entails several key steps as follows. The first step would be to meet with SFPUC and MEA staff to determine the CEQA review requirements and process and meet with Daly City, as appropriate. The next steps would entail the preparation of an administrative review draft of the IS and Draft MND for review by SFPUC and MEA staff. The IS will be an expanded discussion of impacts. It will focus on the issues of importance. The IS will describe the project and provide information about the Lead Agency, contacts, project location, project and plan description, zoning, surrounding land uses and setting, approvals required by other agencies. As required by CEQA, the MND and its supporting IS will address aesthetics, Biological Resources, Hazards & Hazardous Materials, Mineral Resources, Public Services, Utilities/Service Systems, Agricultural Resources, Cultural Resources, Hydrology/Water Quality, Noise, Recreation, Air Quality, Geology/Soils, Land Use/Planning, Population/Housing, Transportation/Traffic and Mandatory Findings of Significance

The project manager will meet with SFPUC and MEA staff representatives to review comments and discuss an approach to their resolution. EDAW will submit a revised screencheck IS and Draft MND for review by SFPUC and MEA staff. We assume that comments and edits on the screencheck draft IS and MND will be minor changes, primarily editorial in nature, and will not include new issues or substantive changes. Upon receipt of SFPUC and MEA comments, we will make final changes and submit a camera-ready master copy and digital copy of the IS and Draft MND.

EDAW assumes that the SFPUC will handle printing and distribution of the Draft MND and IS. However, EDAW can handle this for the SFPUC as an additional service.

The EDAW project manager will attend one public hearing on the Draft MND and IS to receive oral comments. As an optional service, EDAW can arrange for a court reporter to document oral comments on the Draft MND and IS.

Following close of public review of the Draft IS and MND, EDAW will respond to comments of the public. EDAW will make revisions to the Draft MND and IS and prepare written responses to comments.

The EDAW project manager will attend one public meeting of the Commission to adopt the project. The project manager will be available to present the results of the study and answer questions.

Deliverables:

• Categorical Exemption Form (if appropriate)
• Administrative Review Draft IS and MND
• Screencheck Draft MND and IS
• Publication Draft MND and IS
• Final MND and IS
• Response to Comments Paper
• Presentation Material


Task 8 – Obtain all necessary regulatory permits

EDAW will assess regulatory permits needed, identify a permitting strategy and plan and discuss and review the schedule with the SFPUC Project Manager. We will develop draft permits for the project for review by SFPUC Staff and attend one meeting with each permitting agency. For purposes of general planning, we assume three permitting agencies will be involved with the project: US Army Corps of Engineers, California Department of Fish & Game, and the San Francisco Bay Regional Water Quality Control Board. City and County permits also will be discussed. As noted, a basic assumption underlying Phase 1 is that lengthy permitting processes that would prevent implementation of an increase in the lake level beginning Autumn 2002 would not be necessary. Simple, short-duration permitting is assumed to be a key criterion for selection of a proposed raise in lake level

Deliverables: Memorandum on Regulatory Requirements and Implementation Plan Permit Applications

Task 9 - Project Coordination and Public involvement Meetings

EDAW understands that the SFPUC generally prefers to take a lead role in planning and implementing public involvement meetings. The EDAW team will assist SFPUC staff in identifying the public involvement goals and strategy. EDAW will coordinate with Ward Associates to prepare informational handouts and presentation materials as needed and, if requested, the team can assist in noticing, logistics planning and open house meeting set-up.

We anticipate that the team will be present as information resources, and can serve as facilitators if desired. For purposes of general planning we assume that the following team members would be present at the public meetings: Mark Winsor (project manager), Clint Kellner (terrestrial and wetlands biologist), Jeff Hagar (fisheries biologist), Beth Goldstein (hydrologist), and Amy Merritt-Smith (water quality analyst). We assume participation in two public meetings, as noted in the RFP. Printed materials will be provided on a time and materials basis.

EDAW will prepare a written summary of the meetings including comments received. The project manager will prepare a written monthly progress report. The project manager will meet at least monthly with the SF PUC project manger to discuss the status of the work program.

Deliverables: Public Presentations and Monthly Progress Reports

Task 10- Develop Implementation Schedule

EDAW will develop an implementation schedule enumerating all the tasks that would be necessary to raise the level of Lake Merced. This would include the mitigation measures and monitoring that would be necessary as part of the environmental review and permit requirements. It may also include other actions that are outside of the purview of the environmental review process. The shoreline of the lake will be examined with staff of the PUC to ensure that all of the actions have been included in the implementation schedule. Staff of the PUC and other knowledgeable individuals including selected stakeholders will be consulted regarding actions needed prior to increasing the water level of Lake Merced. Some actions that might be included are the removal of the clay pigeon wastes from the rod and gun club that lines a portion of the shore of Lake Merced and the removal of tules at selected fishing locations.

Phase 2 – Alternatives Analysis of Source Waters

Hetch Hetchy water can only be used for a limited amount of time (assumed 3 years) for raising the level of Lake Merced and an alternative source of water will need to be identified. This aspect of the program to raise the level of Lake Merced entails identification of a suitable alternative source of water and then addressing associated issues with its use. We will identify environmental, regulatory, and operational issues that will need consideration and definition in order to use recycled water and/or treated stormwater as source water to raise and maintain the level of Lake Merced. We will assume no change in the current designated beneficial uses of Lake Merced.

Phase 2 will consist of three primary tasks:

Task 1 – Develop the Work Plan

Task 2 – Review and assess the operational, environmental and regulatory issues

Task 3 – Project Coordination and Public Involvement Meetings.

Task 1 – Develop the Work Plan

The work plan can be divided into three aspects: operational, environmental, and regulatory. The operational portion of the project entails review of ongoing studies to identify a source of recycled water and treated stormwater, the ability to deliver the water to Lake Merced, and the need for any treatment requirements for the water. Sources currently identified are recycled water from either the North San Mateo County Sanitation District and/or City and County of San Francisco, or treated stormwater from the North San Mateo County Sanitation District.

The work plan for the environmental portion of this project entails identifying various levels of nutrients for the analysis, determining the applicability of the models used in Phase 1 to analyzing these alternatives, and how aquatic ecology, especially fisheries, will interact with these water quality analyses.

The regulatory issues will be determined by examining the effect of the design water level on wetlands and special-status species (as determined in Task 4 of Phase 1). A strategy for acquiring the permits will be developed as part of Task 2. Task 1 also will include an identification of data gaps.

Deliverables: Draft and Final Work Plans

Task 2 – Review and Assess the Operational, Environmental, and Regulatory Issues

Operational

We will work with SFPUC staff and its consultants and North San Mateo County Sanitation District to describe the proposed facilities, their operational characteristics and comparative costs. The objective will be to describe all project facilities and operations as they relate to the desired goal of raising lake level under the constraints of regulatory requirements, adopted plans and programs and/or potential environmental impacts. The need for any additional facilities necessary to deliver water to Lake Merced and the need for any additional treatment of the water that would go to Lake Merced will also be described for this task.

Environmental

Water Quality

Merritt-Smith Consulting will assess the impacts of recycled water and treated stormwater on the quality of water in Lake Merced. The effect of the different nutrient constituents in the source water on nutrient cycling and related effects will be examined and related to impacts on algal growth and aquatic ecological health. MSC will assess nutrients, dissolved oxygen, and temperature in Lake Merced and relate these to the criteria established by the San Francisco Bay Regional Water Quality Control Board for the lake as well as general aquatic system quality. The analysis will include different lake levels. The October 2001 analysis (and the knowledge of Lake Merced gained by conducting the analysis) will facilitate evaluation of the impacts directly on algal growth, nutrient concentration, dissolved oxygen, and temperature.

MSC will review the adequacy of the data on water quality parameters such as

• Algal growth nutrients
• Algae production
• Water clarity
• Temperature
• Dissolved oxygen


MSC also will review key water quality characteristics of the water supply alternatives including:

• Source water quality
• Discharge location
• Discharge flow
• Discharge frequency, timing


Water Supply Systems

To address longer-term lake augmentation, using sources of supply, such as tertiary-treated reclaimed water, stormwater or other sources, MSC and HCE will define the work elements, level of effort and schedule necessary to identify:

• Timing and quantities of deliveries for different supply options;
• Types of facilities required for conveyance and treatment of water supply;
• Planning-level capital and operating costs of facilities;
MSC and HCE will review reports and documents from past groundwater and water quality assessments of Lake Merced, including:
• Earlier modeling results and models.
• Documents developed by CH2M-Hill for Daly City, including Vista Grande stormwater evaluation and Corollo for the recycled water source project; groundwater modeling operation and recycled water alternatives
• Regulatory permits and requirements for past lake filling programs.
• Hydrologic data and assessments.
The team will review available information developed for water supply alternatives to date.

Aquatic Resources

HES will coordinate with MSC regarding assessing impacts to the fishery from nutrient loading. The impact analysis to the fishery will consider changes in water quality (e.g., temperature, dissolved oxygen, pH) and water quantity (e.g., lake surface level, lake strata) to evaluate changes or shifts of the habitats of key aquatic species. Effects to existing and potential beneficial uses of fishery resources will be determined largely through projected changes in water quality conditions.

Effects on Beneficial Uses

This will entail documenting the beneficial uses and determining the effect of changing the level of Lake Merced on each use. Beneficial uses would include potential municipal and domestic water supply, trout habitat, wildlife habitat, bird watching, outdoor recreation, emergency water supply, etc.

Cold water aquatic species such as trout require water that is both cold and well oxygenated. Adding water to the lake can increase the amount of deeper, cold water habitat that can be utilized by trout; however, that is beneficial only if it is of suitable quality. If more nutrients, such as nitrogen and phosphorous, enter the lake through the addition of relatively nutrient-rich water, increases in productivity (eutrophication) may result. Although the process is complex and difficult to predict precisely, eutrophication could encourage the growth of more food items for fish, such as phytoplankton , zooplankton, small forage fishes, and aquatic insects. However, there is also the potential for increased eutrophication to promote photosynthesis and the increase of algal biomass, which eventually sinks to the lake bottom. There the detritus is consumed by bacteria, using the available oxygen during the process, and creating anoxic conditions in the deeper waters. Additionally, bacterial decomposition of the detritus also favors the formation of hydrogen sulfide, which is toxic to both invertebrates and fish. Trout may therefore become "squeezed out" between anoxic water at greater depth and water that is too warm near the surface.

In order to evaluate the potential effects, and assist in the selection of sound management alternatives, a clear understanding of the lake’s fisheries resources will be one of the key factors. The analysis must also consider changes in water quality conditions that influence these species with particular attention to factors such as temperature and nutrients. This will be accomplished through the review of existing information, identifying data gaps, suggesting field surveys, if necessary, and evaluating the project alternatives. Information developed in Subtask 3.4 will be used on the basis of the impact assessment.

This task will synthesize information developed in Task 1 (and Task 2, if deemed necessary) of Phase 1 on the status and condition of fisheries resources with information on the type, location, and magnitude of projected future lake level augmentation strategies to identify potential impacts on these species. Impact analysis will consider changes in water quality (e.g., temperature, dissolved oxygen, and pH) and water quantity (e.g., lake surface level, and lake strata) to evaluate changes or shifts of the habitats of key (up to six) fish species. This task will involve close coordination with the hydrologic modeling task and will use the results of that modeling. Effects of the project alternatives to existing and potential beneficial uses of fishery resources will be determined largely through projected changes in water quality conditions.

Regulatory

This task entails acquisition of the necessary regulatory approvals for the project. This includes a preliminary determination of the likely CEQA review process and associated document. The Corps regulations indicate that addition of water is a regulated activity according to the Clean Water Act. This task will involve the necessary work to identify the needed permits and information required for the project to proceed. EDAW will describe the process for obtaining each permit, and timelines for their completion as well as overlaps and linkages of information between the CEQA document and permits.

Deliverables: Technical Memoranda summarizing the process and findings for each of the above sections.

Task 3 – Project Coordination and Public Involvement Meetings

EDAW understands that the SFPUC generally prefers to take a lead role in planning and implementing public involvement meetings. The EDAW team will assist SFPUC staff in identifying the public involvement goals and strategy. EDAW will coordinate with Ward Associates to prepare informational handouts and presentation materials as needed and, if requested, the team can assist in noticing, logistics planning and open house meeting set-up.

We anticipate that the team will be present as information resources, and can serve as facilitators if desired. For purposes of general planning we assume that the following team members would be present at the public meetings: Mark Winsor (project manager), Clint Kellner (terrestrial and wetlands biologist), Jeff Hagar (fisheries biologist), Beth Goldstein (hydrologist), and David Smith and Amy Merritt-Smith (water quality analysts). At this point, we do not know the number of meetings that will be required for this process. Printed materials will be provided on a time and materials basis.

EDAW will prepare a written summary of the meetings including comments received. The project manager will prepare a written monthly progress report. The project manager will meet at least monthly with the SF PUC project manger to discuss the status of the work program.

Deliverables: Public Presentation Materials and Monthly Progress Reports