LAKE MERCED COMPREHENSIVE MANAGEMENT PLAN
INTRODUCTION
Lake Merced (the Lake) is an important water, recreational, and natural resource for the City and County of San Francisco (the City) and the surrounding community. In recent years, the Lake and its surrounding environs have deteriorated due to increased use, decreased maintenance, and the decline of the Lake water level. Because of Lake Merced’s diverse beneficial uses, multiple City, state, and federal agencies have jurisdiction at the Lake. The Lake Merced Comprehensive Management Plan (Lake Merced CMP) has been developed to improve Lake conditions by providing guidance and direction to the appropriate City, state and federal oversight agencies. The Lake Merced CMP has been developed with the cooperation of several City agencies, involved citizens and community groups.
The beneficial uses of Lake Merced are:
Ø Regional Recreational Resource. As a large freshwater body in San Francisco, Lake Merced offers various recreational opportunities in a natural setting. Lake Merced is host to fishing, boating, skeeting, jogging, bicycling, golfing, picnicking, and appreciation of the natural environment.
Ø Significant Natural Resource and Education Area. As the most important avian habitat in San Francisco, Lake Merced is critical to the reproductive ecology for as many as 50 bird species. It is a valuable habitat for thousands of migrating birds and the site of diverse native plant and animal populations.
The purpose of the Lake Merced CMP is to identify the actions and funding
necessary to protect and enhance the Lake’s beneficial uses and to guide
the management of Lake Merced into the 21st Century.
SITE DESCRIPTION
Lake Merced is located in the southwest quadrant of the City (see Figure 1). It is delineated by John Muir Drive, Skyline Boulevard, and Lake Merced Boulevard. In addition to nearby public and private recreational facilities, the Lake is bordered by private residences, schools, and a wastewater treatment facility. As the largest freshwater body in San Francisco, Lake Merced supports numerous recreational activities: boating, fishing, golfing, jogging, bicycling, picnicking and appreciation of the natural environment. Figure 2 identifies land uses at and near Lake Merced; Appendix A is a "Site Inventory".
Lake Merced is rich in natural plant and wildlife habitat. The vegetation at Lake Merced consists of a mosaic of wetland and upland species. The mesa overlooking the north bank of East Lake is one of the few areas which continues to support native vegetation, it has an abundant community of north coast scrub plants. Exotic species dominate the majority of the uplands surrounding the Lake. The Golden Gate Audubon Society estimates that as many as 50 species of birds could be breeding along the shores. In addition, the Lake habitat provides valuable refuge for thousands of migratory birds. Although no comprehensive inventory exists, it is known that a variety of fish, invertebrate, reptiles and mammals utilize the Lake’s aquatic and terrestrial ecosystems. Sixteen special status species have been known or have the potential of occurring at the Lake. Consequently, the Lands and Natural Areas Project of the California Resources Agency listed Lake Merced in its 1988 annual summary of "Significant Natural Areas of California."
Lake Merced is located within the Westside Groundwater Basin, and Lake
level is related to the underlying groundwater aquifer. The Westside Groundwater
Basin runs south from the northern edge of Golden Gate Park, southward
through Daly City and southeast across the peninsula to end near the San
Francisco International Airport. (See Figure 3.) A summary of the Lake’s
hydrogeology is contained in "Lake Merced Hydrogeology" as Appendix B.
Lake Merced itself is divided into three water bodies by two artificial
causeways (Figure 2). The Lake bodies are referred to as North, South and
Impound Lake. The eastern portion of North Lake is often referred as East
Lake. Based upon the Lake’s water level as of September 11, 1997, the South
Lake has a storage capacity of 578 million gallons, which is approximately
4.0 days supply based upon the City’s current daily demand of 87 million
gallons.
JURISDICTION
Agencies
The Spring Valley Water District (Spring Valley) developed Lake Merced as a potable water supply for San Francisco in the 1870s. After 1910, Spring Valley developed other supplies and ceased pumping water from Lake Merced for domestic use. During this period, Lake Merced began to be viewed as an emergency water supply by Spring Valley, largely due to water quality concerns caused by increasing development in the Lake’s watershed.
In 1930, Spring Valley sold the Lake Merced tract to the City, which manages the Lake through the San Francisco Public Utilities Commission (SFPUC). In 1950, the SFPUC passed a resolution authorizing the San Francisco Recreation and Park Department (SFRPD) the "right to occupy, use and improve for park and recreational purposes" the lands surrounding the Lake. (See SFPUC Resolution No. 10,435, see Appendix C.) The SFPUC has maintained ultimate responsibility for Lake Merced as it is a potential municipal water resource.
In addition to the SFPUC and SFRPD, several other regional, state and federal agencies have authority over the activities and proposed projects at Lake Merced. Table 1 identifies the agencies that have jurisdiction at Lake Merced and their area of authority.
City Resolutions and Ordinances
In 1991, the San Francisco Board of Supervisors (SFBoS) passed Article 22, the Recycled Water Use Ordinance (Ord. 390-91 and 391-94). This ordinance mandated the development of the groundwater and recycled water for maximum beneficial use wherever reasonable. In response to this ordinance, the Groundwater Master Plan (GWMP) was recently completed. The GWMP has greatly advanced the understanding of the Lake and its response to groundwater pumping patterns. In 1994, recognizing the rapid decline of Lake Merced lake levels since 1979 (see Figure 4), the SFBoS passed Resolution No. 165-94 urging "the Water Department and the Recreation and Park Department to take all necessary steps to raise the water levels at Lake Merced". Copies of SFBoS Ordinance Nos. 390-91 and 391-91, SFBoS Resolution No. 165-94 are contained in Appendix C.
In 1995, the SFPUC passed Resolution No. 95-0082 expressing its desire to protect Lake Merced and the underlying aquifer. The SFPUC resolution directs staff to conduct the necessary studies and investigations to enable the SFPUC to make the final decisions to protect the Lake and its groundwater resources. The knowledge gathered during the development of the GWMP will be an important reference for the Lake Merced CMP. A copy of SFPUC Resolution No. 95-0082 is contained in Appendix C.
.
COMPREHENSIVE MANAGEMENT PLAN DEVELOPMENT
REASON FOR DEVELOPMENT
In response to policy direction from the SFBoS and SFPUC as well as community concern, the City has developed the Lake Merced CMP because it recognizes that Lake Merced has been declining and conditions at the Lake are deteriorating. The Lake Merced CMP provides a blueprint for the cooperative, coordinated management of Lake Merced for the protection and enhancement of all the Lake’s beneficial uses.
Development of the Lake Merced CMP is the first step to protecting and enhancing the Lake’s resources. It identifies the actions to be taken and the process by which the actions will be implemented and coordinated. It also identifies the City agencies responsible for conducting the specified actions and opportunities for community involvement throughout the implementation of the Lake Merced CMP. The next step will be the implementation of the Lake Merced CMP.
DEVELOPMENT APPROACH
SFPUC and SFRPD staff together with the community began the development of the Lake Merced CMP in Fall, 1996. Members of the community and representatives from the various organizations and City departments participated in many hours of public discussion. The outcome of these discussion resulted in the identification of Goals for each of the beneficial uses and Action Items to be implemented to achieve the Goals. The Goals and Action Items are documented in this Lake Merced CMP.
City Project Team
Specific City staff have been identified to assist the SFPUC and SFRPD staff with the formulation of the Lake Merced CMP and to continue the inter-departmental relationships critical to its successful implementation. The City project team membership represents the departments with influence and interest in the management of the Lake. Individuals with specific expertise and experience valuable to the Lake Merced CMP were selected as department representatives. Table 2 lists the departments represented on the City team and their department contact.
Public Participation
Public participation was solicited for the Lake Merced CMP formulation through regular workshops and workgroup meetings. Beginning in November, 1996 monthly public workshops have been held (1) to gather public input regarding the community’s concerns, (2) to develop a forum to address these concerns, and (3) to educate the community regarding the technical issues and planning process required to implement improvements at Lake Merced. Workshop attendance ranged typically between 30 to 60 individuals. See Appendix D for a calendar of workshop dates and locations.
As a result of the diverse, interdependent resources at the Lake, the Lake Merced CMP is divided into three program areas which correspond to the Lake’s beneficial uses: Water Resources Program, Recreational Use Program, and Significant Natural Resource & Education Program. As an outgrowth of the monthly workshops, three workgroups were formed to address each of the program areas. The workgroups were facilitated by City staff. Each workgroup was tasked with developing Goals to enhance its program area and to identify the Lake Merced CMP Action Items required to achieve the Goals. See Appendix D for a calendar of workgroup dates and locations.
Other City Documents
Lake Merced has been the subject of two City documents: "Lake Merced Water Resource Planning Study" (May 1993) and "Draft Lake Merced Recreational Use Master Plan" (1996). The Lake Merced Water Resource Planning Study identified specific tasks requiring further study or completion; for example, implement monitoring program; develop and evaluate water resource alternatives. The Lake Merced CMP has built upon the findings of this earlier planning study and, where appropriate, included many of its tasks as Lake Merced CMP Action Items. The "Draft Lake Merced Recreational Use Master Plan" (1997) has been incorporated, in its entirety, into the Lake Merced CMP Recreational Use Program. Consequently, the Lake Merced CMP Recreation Use Program will serve as the SFRPD’s Lake Merced master planning document.
Two other reports have and will address Lake issues as they relate to
larger planning efforts, "The San Francisco Groundwater Master Plan" and
"The San Francisco Integrated Water Resources Plan" as part of the "San
Francisco Water Supply Master Plan" (in preparation). The findings and
recommendations of these documents will be incorporated, as appropriate,
into the Lake Merced CMP.
COMPREHENSIVE MANAGEMENT PLAN IMPLEMENTATION
The preparation of this document represents a major step to improving Lake conditions. The draft Lake Merced CMP will be presented to the San Francisco Public Utilities Commission and the San Francisco Recreation and Park Commission in October, 1997. The draft Lake Merced CMP will be available for review and comment through December 12, 1997; after which time, the Commissions’ and community’s comments will be incorporated into the final Lake Merced CMP.
The next step to improving Lake conditions is the implementation of this document. The Lake Merced CMP was designed to not require environmental review. However, many of the Action Items identified in the Lake Merced CMP will require individual environmental review prior to final approval. (See Appendix E, "California Environmental Quality Act; Statutes and Guidelines.) The reason that the document was designed in this manner was to ensure that Action Items that could be implemented immediately and without environmental review would proceed independently, yet aware of the possible affects, of Action Items requiring environmental review. Currently, several of the Action Items are being implemented, for example, WRS-1.5, WRS-3.3.
Each Action Item is unique. Implementation will depend upon the specific tasks described in the "what" definition of the Action Item. However, the general plan for Action Item implementation is to identify what needs to be done, why it needs to be done, determine who needs to perform the work, secure funding for the work, inform all managing agencies that the work is being considered, check to determine if environmental review is require, and to begin the work. Progress on the state of implementation of each of the Action Items will be tracked by the SFPUC.
The City project team will meet monthly to report and discuss the status of the implementation of Lake Merced CMP and to facilitate Action Items which require inter-departmental coordination.
Quarterly public meetings will held with the community. The purpose of these meetings will be for City staff to report on the status of the implementation of the Lake Merced CMP and for the community to report on issues of concern. As specific issues are identified that require more in-depth discussion and study, special workgroups will be formed to address these issues. The active support of the community is a critical component for the successful implementation of the Lake Merced CMP.
FUNDING, COSTS and SCHEDULE
Funding
Various funding sources are currently available for project implementation, including the Groundwater Development Program for groundwater resource development; the 1987 Park Bond for capital improvements of recreational facilities; and the Open Space and Park Renovation Program for implementation of the Significant Natural Resources And Education Program.
Water Resources
The Groundwater Program is a multi-year, phased program adopted to develop and protect groundwater resources in San Francisco. Improving the management of Lake Merced as a groundwater resource has been included in the SFPUC Groundwater Program. Program funding has been approved for the 1997/98 fiscal year. Improving the water quality and water supply resources of Lake Merced is in the SFPUC capital improvement program.
Recreation
In 1987, City voters approved a bond measure to provide capital projects funding for six SFRPD facilities, one of them being Lake Merced. From this Park Bond, the anticipated budget for various improvements at Lake Merced was $1.1 million. Improvements will be implemented in the recommended order of priorities until all available funds are expended. (See Appendix F "Capital Improvements Implementation Priorities".) However improvements, which can be accomplished at little or no cost, may be implemented out of the recommended sequence.
The 1987 Park Bond cannot fund maintenance. SFRPD does not recommend Lake Merced capital improvements without adequate maintenance provisions.
Maintenance for the lands under the jurisdiction of the SFRPD may be funded through the General Fund or the Open Space and Park Renovation Program. Other resources for the upkeep of City parks are being explored, including volunteer programs.
Significant Natural Resource & Education
Funding through the Significant Natural Resource Areas Management Plan (SNRAMP) will be available from the Open Space and Park Renovation Program to partially or wholly fund programs associated with natural area preservation and enhancements. It is anticipated that the SNRAMP will fund the majority of the Lake Merced CMP Actions Items associated with preservation and enhancements of the natural environment.
Additional funding may be available through private donations or grants. Future funding could be available through bonds or special assessments or the solicitation of existing sources.
Project funding should cover program development, construction costs and other associated costs, such as consultant services, design development and construction management.
Costs
Estimated project costs are shown for the Action Items under "Action Plan". However, the actual cost of an Action Item will vary, based upon the final project program and site conditions. Various Action Items will require a program proposal to be developed. For this reason, costs are not yet available for these Action Items; these costs have been identified as " to be developed" or "TBD". Recreational Program costs which are part of existing SFRPD programs are identified as "not applicable" (N/A); this indicates that implementation of this Action Item does not result in any additional costs to SFRPD.
Schedule
Table 3 identifies an estimated schedule for the implementation of the Action Plan. This schedule is only a preliminary estimate of the anticipated duration and timing of Action Items. This schedule will be updated regularly during the implementation of the Action Plan and revised schedules will be presented at the quarterly public meetings.
SIGNIFICANCE AND STATE OF LAKE MERCED
Lake Merced is a multi-cultural facility that functions as an alternative water resource for emergency use, a recreational and educational resource, and a host to significant communities of plant and animal wildlife. However, growing reliance on the aquifer, increased visitor usage and invasive, non-native plant species threaten its viability as a regional resource. The following is a summary of the significance of the Lake’s resources and a brief assessment of the condition of these resources.
Municipal Water Resource
Water Quality
In 1950, the SFPUC formally set forth the primary purpose of Lake Merced as a "potable water supply" for the water consumers in San Francisco (See Appendix C, SFPUC Resolution No. 10,435). However, Lake Merced has not been managed as a potable water supply, rather it has been managed as an alternative water resource to be used during an emergency primarily for fire and sanitary control and secondarily for potable use. Under the Surface Water Treatment Rule, Lake Merced could not be considered potable unless its waters were filtered and disinfected. Currently, there are no filtration or disinfection facilities at Lake Merced. "Alternative water sources" for emergency potable use are allowed by the California Department of Health Services if they are disinfected and their distribution is accompanied by a Boil Water Order (BWO) or Unsafe Water Alert (UWA).
Water Quantity
Currently, only South Lake is hydraulically connected to the Lake Merced Pump Station (LMPS). Based upon the Lake’s water level as September 11, 1997, the South Lake has a storage capacity of 578 million gallons of water, which represents approximately 4.0 days of supply for the City at its current demand of 87 million gallons per day.
Infrastructure
During an emergency, Lake water can be pumped either
(2) directly from the Lake using San Francisco Fire Department (SFFD) pumper trucks. A series of SFFD pumper trucks could transport Lake water throughout the western half of the City for fire fighting purposes. In addition, pumper trucks could deliver Lake water to the SFFD’s Auxiliary Water Supply System (AWSS). Water used for fire fighting would be screened but not disinfected.
Lake Merced is a dynamic system that is related physically to the Westside Basin aquifer. This relationship is influenced strongly by the variability in the inflows and outflows to the Lake. When the balance of water flowing into the Lake is greater than the water outflow, Lake level rises. Lake level falls when more water leaves the Lake than enters it. Over time, the various influences on the Lake - natural and human-induced - have resulted in variations in the level of the Lake (Figure 4).
The sources of the water flowing into Lake Merced include precipitation, groundwater, stormwater runoff, and direct addition (from various sources, e.g., surplus SFPUC system water or water from dewatering operations such as Oceanside Water Pollution Control Plant construction). Water leaves Lake Merced either through evaporation or groundwater outflow. The physical connection to the Westside Basin aquifer is complex. In some parts of the Lake (primarily the northern and northeastern areas), the Lake is directly related to the water table. In the southern part of the Lake (Impound Lake), the bottom of the lake is above the water table.
Because of the relationship of Lake Merced to the Westside Basin and the value of the Lake as a regional resource, Lake Merced will be integral in the development of the Westside Basin Groundwater Management Plan (WBGMP). The WBGMP is being developed by the SFPUC and the potable users of Westside Basin groundwater - Daly City, San Bruno, and the California Water Service Company - to protect water supply and water quality of the Westside Basin's groundwater resources through cooperative management. It is anticipated that improved groundwater conditions throughout the Westside Basin will have the added benefit of improving the level of Lake Merced over the long term.
Regional Recreational Resource
Since 1950 when SFRPD was given permission to manage the lands surrounding Lake Merced for recreational uses, facilities have been developed for various recreational opportunities. A paved pathway allows jogging, walking, roller blading, dog walking and bicycling along the perimeter of Lake Merced. An artificial causeway supporting Harding Road contains facilities for fishing, boating, sculling and picnicking. Additional fishing piers have been constructed at various locations along the shores of Lake Merced. A golfing facility, the Jack Fleming/Harding Park Golf Course, is nestled between North and South Lakes. A skeet shooting facility (Pacific Rod and Gun Club) and a police firing range are situated along the western shore of South Lake. Paved parking areas allow easy access to the Lake. Other visitor provisions, such as restrooms and a par course, are available at a few locations. For more information on the various facilities at Lake Merced, see Appendix A.
As one of the few natural environments and the largest freshwater body in San Francisco, Lake Merced also provides opportunities for leisure enjoyment of the natural environment. Lake Merced has been identified as a significant natural resource fostering a diversity of native plant and animal wildlife.
With its variety of recreational opportunities and urbanization of the surrounding area, Lake Merced has become a popular destination. The existing facilities have proven to be inadequate for the increasing number of daily visitors. Basic user amenities, such as restrooms, telephones, bicycle racks, trash receptacles and information booth, are lacking. Increased traffic along the perimeter roadways is a concern to the safety of visitors. Passersby and residents living across from Lake Merced are interested in preserving and enhancing views of this natural environment.
At the same time, increased pressures on existing facilities have reduced their quality for use. Compounded by limited staffing and deferred maintenance, the recreational facilities at Lake Merced are deteriorating. Informal foot trails in various locations have caused erosion and sometimes detrimentally affected existing native plant communities.
Significant Natural Resource and Education Area
Lake Merced is designated a "Significant Natural Resource Area" by the San Francisco Recreation and Park Commission (January 19, 1995, Resolution No. 9501-008). Significant natural resource areas are generally remnants of the original landscape that stretched from San Bruno Mountain to the Golden Gate Headlands. Natural resources areas include woodlands, grassy open fields and hilltops, chaparral, coastal scrub, mud flats, shorelines, sand dunes wetlands, fresh water lakes and streams. Today only very small examples of this rare environment remain as footnotes to the ecological history of San Francisco. These areas contribute to the region by (1) providing habitat to unique or endangered plants and animals, (2) offering exceptional geological formations and/or (3) serving as greenbelt corridors for wildlife. In addition, with the tremendous diversity of plant and animal life that exists at the Lake, opportunities exist to educate the public about natural ecosystems. The protection, preservation and restoration of Lake Merced is a high SFRPD priority.
As the largest body of freshwater in San Francisco with a prime location along the Pacific Coast Flyway, Lake Merced and its surrounding environment contain critical habitat for aquatic and terrestrial organisms. A reconnaissance field study revealed that up to sixteen special status wildlife species are known to or have the potential to occur at Lake Merced. For example, the state-threatened bank swallow nests at Fort Funston and feeds at Lake Merced. Also, the saltmarsh yellowthroat, which nests in the tules around the lake, is a candidate for federal listings as being threatened or endangered. In addition, The Golden Gate Audubon Society estimates that as many as 50 species of birds may breed along the shores of Lake Merced, including herons, sores, Virginia rails, marsh wrens and various waterfowls.
No inventory of the mammals, fish, amphibians, or reptiles currently exists. Mammals expected to occur in the upland habitats are species that adapt to the urban environment such as squirrels, mice, gophers, rats, bats, rabbits, and raccoons. Reptiles most likely to occur include the Western fence lizards, northern alligator lizards, ringneck snakes, and coast garter snake. Western pond turtles, a federal candidate for listing and a state species of special concern, were observed in 1976. Fish expected to inhabit the Lake are Black bass, catfish, rainbow trout, carp, and possibly tule perch. An interesting note is that a relic invertebrate which survived the change from an estuary to a fresh water lake, Neomysis mercedis, was described by Holmes (1897) on the basis of specimens collected in Lake Merced by H.P. Johnson in 1895. The shallow areas around the Lake are expected to foster a high density of invertebrates which support the various shorebirds.
The vegetation around the lake consists of wetland and upland vegetation types that occur as a series of linear bands. The most abundant community of north coast scrub plants occurs on the mesa overlooking the north bank of East Lake. This assemblage of native flora includes California sage, yellow bush lupine, lizard’s tail, beeplant, Hooker’s evening primrose, coyote brush and poison oak is found nowhere else around the Lake.
The increase in the feral cat population, non-point source pollution, invasion, non-native plants, erosion, litter, and potential human disturbance on wildlife threaten Lake Merced’s ability to continue as a significant natural resource.
ACTION PLAN
As a result of the diverse resources at the Lake, the Lake Merced CMP is divided into three program areas which correspond to the Lake’s beneficial uses: Water Resources, Recreational Use, and Significant Natural Resource & Education. For each of the program areas, Goals were defined to guide the enhancement and protection of the program’s beneficial use. To achieve the goals, Action Items were defined to enable the achievement of each Goal. Each Action Item is further detailed by identifying the associated "who", "why", "what", "when", "funding", and "cost" as defined below:
who the responsible government agencyTable 4 is a cross-reference of participating agencies, groups, and individuals for the implementation of the Lake Merced CMP Action Items.
why the existing problem or condition that necessitates the Action Item
what the specific action to be implemented, a measurable deliverable (i.e., performance of a study, inventorying a resource, etc.)
when estimated time frame or relative sequence
funding identifies which City department will fund the Action Item and, if known, the City program
cost cost estimate for Action Item implementation
Endnotes
|
|
