[From the U.S. Government Printing Office, www.gpo.gov]
COASTAL ZONE INFORMATION CENTER V~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~V 'QH Z76.5 S36~ 1979 ~~san dieguitolgn ~ esurce enhancement program 1 ~~~~~~~December 7, 1979 I ~~~~~~~To All Interested Parties: The City of Del Mar'and the State Coastal Conservancy are pleased to release the San Dieguito Lagoon Resource Enhancement Program. The program seeks to provide a realistic, yet far-reaching plan for the restoration and enhancement of one of Southern California's few remaining coastal wetlands. It is also hoped that this program will serve as a prototype for enhancement of other wetlands, ensuring that these coastal ecosystems will continue to provide valuable wildlife' habitat, open space, recreation and visual amenities for the future. 3 ~~~~~~~This document represents a full year of effort on the part of the Conservancy and 'City staff, the San Dieguito Lagoon Planning Committee, technical consultants and numerous public agency representatives. A two month review period produced agency and citizen comments which have been addressed in this final document. One of the key features in the development of this program is the enthusiastic participation by so many individuals attempting to pull together a project of such complexity. That this report could be produced is a tribute to the dedication of those community members, agencies and others who are committed to preserving and enhancing what remains of the coastal wetlands in California. 3 ~~~~~~~Now a demanding but exciting implementation program must be begun. Much work lies ahead and we are looking forward to continuation of the excellent support from governmental agencies and the public. * ~~~~~~~Sincerely, William Hea yDirPetrilor Planning and Comun y Development ecuti-ve Officer City of Del Mar State Coastal Conservancy san dieguito lagoon resource enhancement programn DECEMBER 1979 (Second Printing September, 1980) STATE COASTAL CONSERVANCY CITY OF DEL MAR 1212 Broadway, Room 514 1050 Camino del Mar Oakland, California 94612 Del Mar, California 92014 (415) 464-1070 (714) 755-9313 U.S. DEPARTMENT OF COMMERCE NOAA COAS1AL SERVICES CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON, SC 29405-24 13 This document was prepared with financial assistance from the Office of Coastal Zone Management, National Oceanic and Atmospheric Administration, under the provisions of the Federal Coastal Zone Management Act of 1972, and the State Coastal Conservancy. VIP Property of csc Library STATE COASTAL CONSERVANCY CITY OF DEL MAR Board Members City Council Huey D. Johnson,Chairperson Al Tarkington, Mayor Margaret Azevedo, Vice-Chairperson Richard L. Roe, Mayor Pro tem Dorill Wright Gordon Denyes Mary Ann Graves Nancy Hoover Jerome Snyder Hervey L. Sweetwood Lois Ewen Roy Bell Hal Waraas Staff Staff Joseph E. Petrillo Robert A Nelson, City Executive Officer Manager Dennis Machida, Conservancy William T. Healy, Director, Enhancement Projects Planning and Community Coordinator Development Bruce E. Jones, Conservancy Katherine A. Jesch, City Project Manager Project Coordinator Judy Clark, Project Analyst STATE OF CALIFORNIA EDMUND G. BROWN, JR Governor CONSULTANTS Sea Sciences Services, Inc., San Diego: Engineering/Hydrology Pacific Southwest Biological Services, San Diego: Biology Gregory H. Vail: Map Graphics Jeanine Moret: Illustrations' . SAN DIEGUITO LAGOON PLANNING COMMITTEE Don Coordt, Chairman Dr. John Bradshaw Margaret Porter Karen Burger Dr. C. Bishop Spangler Allan Carson Herb Turner Ed Coughran Gregory H. Vail Gloria Hoff Dr. Nancy Weare Dr. Charles D. Keeling Dr. Gerald Winterer Dr. Joseph Lang Gene Yee Jeannie O'Toole SPECIAL THANKS TO: Bruce Browning, Department of Fish and Game Earl Lauppe, Department of Fish and Game Robert Radovich, Department of Fish and Game Maeton Freel, U. S. Fish and Wildlife Service TABLE OF CONTENTS SUMMARY3 Introduction ................................3 Program Significance............................ 4 Physical Environment . .1 Existing Land Use, Jurisdictions and Ownership. ..............7 Enhancement Plan.............................. 8 Implementation. .............................12 Land Use Regulations. ..........................18 Environmental Assessment of the Program. ................20 CHAPTER ONE: SAN DIEGUITO LAGOON PROGRAM INTRODUCTION Program Background. ...........................1-2 Program Significance. ..........................1-4 Objectives. ...............................1-6I Environmental Impact Assessment. ....................1-7 CHAPTER TWO: SAN DIEGUITO LAGOON EXISTING ENVIRONMENT Introduction. ..............................2-2I The Lagoon Setting. ...........................2-3 Natural Resources. ...........................2-7 Habitat Types 2-7I Flora 2-11 Fauna 2-12 Geology 2-20 Soils 2-20 Hydrology 2-21 Development and Use Features. ......................2-23 Governmental Jurisdi cti ons 22 Land Use and Ownership Patterns 2-27 Existing Land Use Regulations 2-29 Recreational Access 2-31I Vehicle Circulation 2-32 Summary of Enhancement needs. ......................2-33 CHAPTER THREE: SAN DIEGUITO LAGOON ENHANCEMENT PLAN Introduction. ...........................3-2 Design Criteria. ..........................3-5I Components of the Plan. .. . . . . . . . . . . . . . . 3-9 Improvements of Tidal Areas 3-9 Wildlife Habitat Improvements 3-14 Improvements for Public Access 3-17 Potential Additional Uses . . . . . . . . . . . . . . . . . . . . . . . .3-20 CHAPTER FOUR: SAN DIEGUITO LAGOON PLAN IMPLEMENTATION Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2 Agency Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . .4-5 Agency Roles 4-5 Cooperative Agreements 4-7 Proposed Acquisitions . . . . . . . . . . . . . . . . . . . . . . . . . .4-9 Permits and Approvals . . . . . . . . . . . . . . . . . . . . . . . . . .4-11 Site Construction and Improvements. . . . . . . . . . . . . . . . . . . .4-14 Monitoring, Maintenance and Policing. . . . . . . . . . . . . . . . . . .4-21 Costs and Funding . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-23 CHAPTER FIVE: SAN DUEGUITO LAGOON LAND USE REGULATIONS Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2 Zoning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3 Supplemental Controls . . . . . . . . . . . . . . . . . . . . . . . . . .5-9 Watershed Management. . . . . . . . . . . . . . . . . . . . . . . . . . .5-12 APPENDICES Recommended Actions for Public and Private Agencies . . . . . . . . . . . A Phased Implementation of Site Construction Work . . . . . . . . . . . . . B Review of the Hydrology and Tidal Influence in the San Dieguito Lagoon. ........... . . . . . C General Guidelines for Coastal Lagoon Management. . . . . . . . . . . . . D GLOSSARY/REFERENCES LIST OF EXHIBITS (Charts and Maps) Wetland Definitions Chart. . . . . . . . . . . 2 Proposed Project Map . .. . .. . .3-11 Lagoon "Before and After" Chart. ......... 17 Access/Circulation Plan Map. ... .. .3-16 Regional Setting Map . . . . . . . . . . .2-4 Proposed Acquisitions Map. .. . . . . . . . . 4-8 Present Environment Map. . . . . . . . . . . .2-6 Chart of Agency Permits and Reviews. . . . . .4-12 Vegetation Habitats Map ....... .... .2-8 Proposed Project Map: Phase One. . . . . . . . 4-16 Rare/Endangered Species Map .......... .2-14 Proposed Project Map: Phases Two and Three . .. .4-18 Wildlife Habitats Map. . . . . . . . . . . . .2-16 Proposed Project Map: Phase Four . . . . . . .4-19 Jurisdictions Map. . . . . . . . . . . . . . .2-4 Proposed Zoning Map. .... . . . 5-4 Land Use/Access Map. . . . . . . . . . . .2-25 Chart of Zoning Descriptions: Del Mar. . . . .5-5 Land Ownership Map .... . .......... .2-26 Chart of Zoning Descriptions: City and Zoning/Floodlines Map. ............. .2-30 County of San Diego ....... . . . . .5-7 Area Reference Code Map* . . . . . . . . . . .3-10 Buffer Area Map. . . . . . . . . . . . . . .5-8 A Also reproduced on inside back cover. I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~------ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ i(IP__ __ U~~a d__lt ago I~eoreehneetpa--, "WETLAND" "MARSH" WHAT ARE THEY?U "ESTUARY" "The estuary and tidal marsh are extraordinary natural systems in which tidalI energy circulates nutrients, animals feed on plants and on each other, and excess nutrients are washed out to feed the organisms which live offshore." (Our Nation's Wetlands, An Interagency Task Force Report coordinated by the U. S. Council on Environmental Quality, 1978)3 "Wetlands" are areas that are inundated by surface or ground water with a frequency sufficient to support a prevalence of vegetative or aquatic life that requires saturated soil conditions for growth and reproduction. (Presidential Executive Order 11990, 42,Fed. Reg. 269r61, 1979) A "marsh" is one form of a wetland, either freshwater or salt, which is dominated3 by nonwoody plants (especially grasses and sedges) often developing in a shallow depressions, river margins, tidal areas, and estuaries. "Salt Marshes" (and salt water swamps) account for only 10% of the nation's wetland resources.I (U. S. Council on Environmental Quality, 1978) An " etay is a semi-enclosed coastal body of water which has a free connection with the ocean, is tidally influenced, and experiences mixing of seawater withI freshwater from land drainage. Estuaries often contain marshes along their edges. A "lagoon" is a narrow inlet connected to the sea that extends inland and often has3 some freshwater drainage entering it, but not to the degree as does an estuary. Much of the lagoon's narrow interior can be marshy. 2 introduction California Department of Fish and Game, U.S. Fish and Wil~life Ser- The San Dieguito Lagoon vice and other agencies with juris- U ~ ~Enhancement Program is a joint diction over the lagoon. effort of the State Coastal Con- servancy and the City of Del Mar The lagoon enhancement program to restore and enhance a degraded has three major components: 1) the wetland on the San.Diego coast. lagoon enhancement plan (chapter 3 The program was developed in of this document), which identifies support of a resource enhance- appropriate activities for the lagoon I ~ ~ment project of the Conservancy and surrounding lands and site improve- and will be proposed as a part ments to support these activities; 2) of the Local Coastal Program the implementation plan (chapter 4), (LCP) now being prepared by which describes appropriate means for the City of Del Mar in accor- carrying out the desired'site improve- dance with the California ments, proposes land acquisitions, Coastal Act of 1976. outlines desirable management arrange- I ~ ~~~~~~~~~~~~~ments and responsibilities, and iden- Conservancy involvement in tifies appropriate funding sources for the enhancement program was ini- each element of the enhancement pro- I ~ ~tiated at the request of the gram; and 3) proposed land use regulat- City in late 1978. The Conser- ions (chapter 5), which are part of vancy awarded a planning grant the Del Mar Local Coastal Program. to the City and authorized Con- The LCP material was prepared by The servancy staff to help develop City of Del Mar to satisfy require- a program for the revitalization ments of the Coastal Act of 1976 and of San Dieguito Lagoon. In pre- will be submitted separately to the I ~ ~paring this program, Conservancy Coastal Commission. and City of Del Mar staff have relied heavily on an analysis de- Chapter 2 contains an inventory veloped for the lagoon in 1977 of existing conditions and assessment by the Cal Poly Coastal Design of enhancement needs and opportunities Group, on a Department of Fish at the lagoon. Supporting technical and Game study of the lagoon, appendices are found at the end of0 I ~ ~and on the studies of private this document, and a substantial consultants engaged specifically amlount of technical information isE for the enhancement program. The contained in the consultants' report, I ~ ~program has been prepared in available at the Del liar Planning close consultation with the San Department and at the ConservancyE Dieguito Lagoon Planning Coin- office, 3 ~~mittee (a citizens advisory group), Coastal marshes and estuaries suffers from a history of sewage are among the most productive and discharges, water diversions, sedi- valuable ecological systems in the mentation, human and pet intrusion, State. They produce large quantities and other disturbances. In spite of food for both marine and terres- of the degradation in habitat quality,I trial organisms along the coast and the lagoon remains a highly signi- provide essential habitat for hundreds ficant wildlife area. It has been of fish and wildlife species. Marine identified by the California Depart- fish enter coastal wetlands to feed ment of Fish and Game and the Federal and also use them as breeding and Bureau of Sport Fisheries and Wild- nursery grounds. According to the life as one of the 19 coastal wet- Council on Environmental Quality, lands of top priority for acquisitionI about one-half of the commercial fish in the State. The lagoon's ecological and shellfish harvest on the Pacific significance and restoration potential Coast is dependent on California have also been recognized by the coastal wetlands. A large variety California Coastal Commission and of migratory shorebirds and water- the Cities of San Diego and Del Mar. fowl spend the winter or stop The rare combination of high biologi- for shorter periods in these areas cal and aesthetic value, high potentialI during annual migration. In addi- for restoration, and high pressure for tion many species of wading birds, development at San Dieguito provides other water-associated birds, and the opportunity to balance a complexI raptors are supported by coastal array of demands within the context wetlands. Five endangered bird and of the 1976 Coastal Act. mammal species are totally dependent on these aeas (see lossary).The San Dieguito Lagoon program San Dieguito Lagoon is one of can serve as a prototype for enhance- the relatively few wetlands remain- ment of other lagoons in California.U ing on the Southern California Coast, Lessons learned in this effort develop- an area which has lost 75 percent of ed a greater understanding of what is its valuable wetland acreage since needed in an ongoing coastal wetlandI the time of European settlement and management and restoration program. which continues to be subject to intense pressures for development. San Dieguito Lagoon-itself has been reduced from 600 to 200 wetland acres 4 ~~~~~~since the turn of the century, and3 physical environment The San Dieguito Lagoon is to build up in the lagoon and located on the northern edge of cnrbtn oproi lsr Dieguito Lagoon IScontributing to periodic closure the City of Del Mar, a rapidly growing coastal community about also deprived the lower San 20 miles north of San Diego Bay. Dieguito River valley of most The lagoon is a 200-acre remnant of its aquifer recharge supply, of a 600-acre area of marshland leading to the degradation of and tidal 6hannels that once groundwater quality (and con- exi s t ed atndhe mouth of tid San sequently to the abandonment existed at the mouth of the Sanofarigtthlgonnte Dieguito iver. Theplanningof farming at the lagoon in the Dieguito River. The planning area encompasses approximately 1930's). 650 acres. This area contains In 1936, over 200 acres of the lagoon system of channels and marshes, surrounding lowlands and lgo elnswr ildi bluffs. The project area is bracetrack/fairgrounds complex. by the ocean shoreline to the west, 5 ~~~~~~~~The construction of a small air- Interstate 5to the east, Via de la field, Highway 101 (now Camino Valle to the north, and the bluffs Vande the mouthe nofCrsth and to the del Mar), and Interstate 5 also and the mouth of Crest Canyon page the south. (See map page 2-6replaced a large portion of the south. (Semawetland area with fill. The lagoon's wetland area was The main channel system of further reduced by the con- the lagoon consists of a single, struction of a diked sewage east-west-running, shallow channel oxidation pond, which was with a fishhook-shaped south fork. used by the City of Del Mar A narrow strip of salt marsh until 1975. borders the western portion of the lagoon, broadening to the east As a result of these acti- where the channel forks. vities, the physical characteris- 16 tics of the lagoon reflect in part I Over the past 70 years, the a degraded biological system. Due lagoon has been degraded by a series to the alteration of freshwater of development activities. With flows and the cessation of tidal E the construction of Lake Hodges influence, the lagoon water pattern Dam in 1918, the supply of fresh is characterized by extreme variances water to the lagoon was dras- in salinity, poor circulation, and tically reduced, allowing silt varying water surface. As the 5W ~~~~~~~~~~~~~~vrinwaesufc.Ath result of these conditions, aquatic Further, the lagoon and surrounding faunal diversity has been minimized environs are visually degraded by (only ten species of fish have been litter and the lack of vegetation identified). The ability of the sys- in certain areas. tern to rid itself of pollutants from Finally, human and domestic animal wastes, plant nutrients, and animal intrusion have disrupted sensi- sediments has also been limited. Fur- tive vegetation and habitat areas. Dogs ther, the lack of circulation in thehaedsutdtlatonlatI lagoon system has resulted in stag- tern nesting attempt. Foot traffic nant water which facilitates the breed- is threatening the Prostrate Hosackia, ing of mosquitoes. The inability of a rare and endangered plant in theI the system to quickly transport water coastal dune areas. to the ocean has led to flooding of low lying areas during the wet season. In spite of the degraded nature3 of the lagoon and surrounding lands, In addition, the hydrological San Dieguito Lagoon retains high characteristics of the lagoon and value as habitat for a large number the loss of wetland acreage to of wildlife species. A variety landfill have resulted in the rela- of habitats still exist at the lagoon-- tive shortage of several habitat coastal dunes, channels, mudflats, types such as freshwater marsh and pickleweed salt marsh, salt flats,I mudflats essential for maximum brackish marsh, riparian vegetation, species diversity and biological maritime grassland, and coastal producti vi ty. In particular, there sage scrub. For its size, the lagoonI is a shortage of feeding and nesting supports a highly diverse bird areas for the endangered least tern populations- 73 upland and 54 water- and Belding Savannah Sparrow. associated species.3 U existing land use, jurisdictions U and owvnership the lower valley of most of its U ~ ~~Del Mar is the southernmost aquifier recharge supply. The of six small but rapidly growing San Dieguito Valley east of beach communities in the northern Interstate 5 is still used for portion of San Diego County. To grazing during part of the year, the south and east, it is bordered but no economically viable ag- by the City of San Diego; to the ricultural land exists in the I ~ ~north, by the unincorporated planning area west of the free- community of Solana Beach. way.' The upland area south of the San Dieguito River-was Population growth in the cleared for the construction of northern portions of the.San the Del Mar Airport runway, Diego coast region has increased buildings and concrete bunkers, substantially in recent years and which were used during World War is e xetdto continue to increase 11. The buildings were sub- at a high rate. sequently used for light manu- facturing industry, but were de- U ~ ~~Significant development has molished in 1970. Several paved encroached into the lagoon area or dirt roads still criss-cross itself, including the 225 acre this area. Del Mar Racetrack and Southern California Exposition complex, Four governmental entities five road and rail crossings of have general jurisdiction over the the lagoon channels, an abandoned air- Planning area: The City of Del Mar, I ~ ~field, oxidation ponds, a recreational the City of San Diego, the County vehicle park, a golf driving range, of San Diego, and the 22nd District various other commercial uses, some Agricultural Association. Except light industry and some residential for the racetrack/fairground complex, development. which is owned by the State of California, and some smaller parcels Parts of the lagoon have owned by the City of Del Star and the g I ~ ~been historically used for City of San Diego, the land within farming, but this activity thie planning area is privately owned.E had to be abandoned in the late The principal private ownerships are I ~ ~1930's due to degradation the Scripps Clinic and Research of groundwater quality caused by property (23.4 acres), the Del Mar overdraft and by the construction 3 8 property (101.7 acres),and the I ~~of Lake Hodges Dam, which deprived Moshtaghi property (87.7 acres) . enhaneret pla The primary objectives of this en- ment, etc., should be located and de- hancement plan are to protect and enhance signed to protect wetlands, scenic val- the esthetic and ecological values of the ues, and wildlife habitat. lagoon and to provide opportunities for public access, recreation, and education Based on these design guidelines, consistent with protection of natural and the following site improvements andI scenic resources. Protection of the lagoon actions are proposed: is based on the zoning and land use regu- lations outlined in the last chapter. construction of tidal basins In order to guide the enhancement work, enlargement of channels several "design guidelines" were developed, .creation of a freshwater marsh as described below (and at page 3-5). establishment of a least tern pre- serve 1. The integrity of existing functioning enhancement of several wildlife natural systems should be disturbed as habitat areas little as possible. .a general cleanup of the lagoon 2. Land alterations should expand the .improvement of pedestrian trails .water surface (with increasing the depth and viewing points (with educat- of channels a secondary function) to improve ional signs)I the tidal prism and increase aquatic habitat. construction of a permanent entrance 3. Land alterations should create a pat- to the reserve tern of water circulation and flushing to reduce mosquito breeding, stagnation, and A few roadway realignments or im-3 pollutant buildup. provements which would not harm the 4. Land alterations should be located to lagoon are also recommended for safety reduce the risk of their being destroyed reasons or for maintenance access to by floods. the lagoon. The plan also suggests 5. Endangered bird species should be iso- the following potential additional uses lated from human and animal intrusion and for future consideration: an aquacul- their habitat should be protected from ad- ture facility, a biological sewageI verse impacts of site alterations. treatment system, preserves for rare 6. The diversity of the spatial pattern coastal plants, a youth hostel and of habitat types should be increased and a nature study center. The following ecotones (transition zones between different sections discuss each site improvement habitat types) should be developed. and activity in greater detail. 7. Recreational access for educational viewing should be controlled and sited to minimize adverse impact on wildlife. 8. Any physical structure, roadway improve- Tidal Basins Three tidal basins wouldlaoncnelwudbwindad be constructed along the lagoon chan- lagoone cannlwud the wipdofnth Fishoo nels (for the code references refer to deepended andrth-es tip join wthe Fihheo map on insideback cover):south channel. The primary benefits 1. he rairoa trange"(Area IV): of these alterations would be to in- a1..5The parcelrofacad lrande crease the tidal prism and provide U a 3.5-cre parcl of vacnt landadditional habitat for aquatic spec- now separated from the lagoon's is ycnetn h ihokt wesohanld byte rxailroad emank-oie the south channel, a 20-acre interior ment, wudbexaaeanjoedisland would be created, which would to Th other wetdhannl byasinpAea X-) provide high quality salt marsh habitat 2aTh abndorted95arn teaeoidaltaion ~Ae XCfor wildlife and would be protected an aandned9.5-cre s e w ge oidaionfrom human and domestic animal in- I ~ ~~pond adjacent to the salt marsh at trusion by the encircling channel. the channel fork would be excav- The north and west channels would also L ated and connected to the south dredged to increase flood carrying capacity channel with a new channel. 3. The southern tidal basin (Area X): the area adjoining the eastern arm In addition to enlarging the of the Fishhook would be excavated main lagoon channels, minor altera- I ~ ~~and graded to create a 10.1-acre -tions of small marsh channels are tidal basin and 5.7 acres of mud- proposed to improve water circu- flats. lation in four areas: the marsh 3 ~~~~~~~~~~~~~and pond area just east of Camino The primary purposes of the tidal del Mar (Area II), the marsh at basins are to increase the lagoon's the channel fork (Area IX-B), the tidal prism and to increase its aqua- winter marsh (Area X-C), and the tic habitat area. The proposed chan- interior island created by the nel and basin enlargements will expand Fishhook extension (Area X-B). the area of the lagoon subject to tidal action (that is, the area be- It is also proposed that the low the elevation of mean higher high mouth of the lagoon be opened on water) from about 40 to 70 acres, an experimental basis if the I ~ ~and is expected to increase the tidal increased tidal prism is insuffi- prism by over 50 percent. Although cient to keep the lagoon open 1 there is no guarantee that this in- naturally and if severe stagnation crease will ensure a permanently o lo aad euti h open agoo mouh, i wil kee theclosed lagoon. Finally, in the long mouth open for a longer period and term, dredging of the main river reduce the need to breach the sand channel would reduce the flood bar mechanically. ~~~hazard in the lagoon. Channel Improvements With the con- Freshwater Marsh The enhance- struction of tidal basins, the south metpa2rpsscnetn the abandoned 14 acre oxidation I Pond (adjacent to the north channel Upland Habitat Enhancement. In all and Interstate 5, Area VII) to a upland areas of the proposed ecologi- freshwater marsh with islands suitable cal reserve (largely Areas IX and X), for bird nesting. Conversion'would the plan proposes clearing of rubble require minor excavation, grading and weeds and revegetating with na-I and supplying the pond with water. tive species. In their present dis- Water losses from evaporation would turbed condition these upland areas be replaced by two windmills pumping receive only limited use by wild-I ground water. The freshwater wetland life. The recommended improvements habitat would increase habitat diver- would increase the habitat value of sity and benefit the overall species these areas, thereby increasing the diversity and biological carryingabnncaddiestofwlie capacity of the lagoon. at the lagoon. The plan also recom- mends preserving and vegetating a Endangered Species' Habitats The new portion of the coastal dunes near theI salt marsh, mudflat and open water areas lagoon mouth (Area I). will provide additional feeding habitat for least terns and feeding, resting, Scenic Improvements. All the siteI and nesting habitat for Belding's ipoeet ecie bv ol Savannah Sparrows. The plan also pro- ipoeet ecie bv ol poses enhancement of nesting habitat substantially improve the scenic for least terns in three areas, all quality of San Dieguito Lagoon byI of which will be covered with light- creating greater vegetative diversity, colored sand favored by terns. more open water and less stagnation. 1. Northern tidal basin: An area of A general clean-up of debris through- higher ground in the salt marsh out the lagoon would enhance scenic just west of the proposed tidal value further. basin (Area IX-B) would be raised further. Recreational and Public Access 2. Southern tidal basin: In extend- Improvements. A need exists to ing the Fishhook to meet the south provide recreational and educational channel, a small island of higher opportunities but also protect theI ground would be left within the lagoon. The enhancement plan there- Fishhook channel extension (Area fore recommends (1) that the existing X-B). trail along the south bank of the 3. Overflow Parking lot: A 12-16 acre lagoon be improved and that "pedes-I Parcel between Jimmy Durante Blvd. trian access" signs be posted; (2) that and the north channel (Area VI) Grand Avenue be maintained but that a would be protected by fencing. gate be constructed at its intersection I The parcel, an overflow parking with San Dieguito Drive, to restrict lot for the racetrack and fair- access to maintenance vehicles-. and grounds during the summer, is one (3) that two viewing sites be improved, which the terns have used tradition- a pedestrian overlook in Area II and ally for nesting but with no suc- the proposed lagoon reserve entrance 10 ~~~~~~~cess recently due to disturbance at the intersection of Jimmy Durante by domestic animals and people. Blvd. and San Dieguito Drive. InI addition, there will be construction of an informational kiosk at the intersection of Jimmy Durante Blvd. and San Dieguito Drive, installation of educational signs around the lagoon reserve, and initiation of a program of public involvement in lagoon restoration, maintenance and educational tours. Active recrea- tional use (volleyball and other sand- lot sports) of the least tern nesting preserve in Area VI would be encouraged in the "off-season" (September-March), when the terns are not nesting. Vehicle Circulation Improvements. Maintenance, but not expansion, of Grand Avenue is recommended. Widen- ing of San Dieguito Drive to serve new residential development should be allowed if filling of the water- way can be avoided, Reconstruction of Jimmy Durante Bridge is recommended for safety and traffic flow reasons, Potential Additional Uses. The enhancement plan recomments further study of several possible addition- al uses for the lagoon and surround- ing lands: (1) a youth hostel or similar overnight facility on the 20-acre "Snakewall" property just west of San Dieguito Drive; (2) preserves for rare coastal plants in the lagoon wetlands; (3) an aquaculture facility in the lagoon or the former lagoon area E east of 1-5; (4) a biological sewage treatment system in the lagoon or former E lagoon area east of 1-5; and (5) an interpretive center. I~~~~~~~~~~~~~~~~~~~~~~~~~~~l implementation The implementation plan addresses The implementation plan proposes the following: public ownership or control (dependent upon availibility of funds and negot- 1. Delineation of proposed ownership iations with land owners) over the and management responsibilities; following parcels (totaling 219.2 2. Identification of short and long- acres): term costs, including acquisition, site development, operation, and 1. The 23.4-acre Scripps Clinic and Research Foundation property along 3. Design of mechanisms to meet pro- Highway 101 west of the railroad ject costs and allocation of fund- in the northwest corner of the ing responsibilities; and project site ; 4. Allocation of initial implementa- 2. The 2.9-acre Jefferson parcel (under- tion responsibilities. water) along Jimmy Durante Blvd. which is now subject to Public Trust easements; In order to permanently enhance 3. The 101.7-acre Del Mar 88 property the lagoon, a complex set of owner- east of the Fishhook ; ship, management and financing arrange- 4 ITe8.-ceMstgipoet ments must be established. These in the southern end of the project arrangements are discussed below. area; and 5. The 3.5-acre railroad right-of- way owned by the Santa Fe Rail- Ownership. The goals of lagoon Road. enhancement and protection will best be met through some form of public ownership control over key Management. The implementation plan areas in the planning area. Though identifies the City of Del Mar and 250 acres of the project area (totaling 650 acres) are publicly the Dpiartment anci e as owned, virtually all of the wetland the primary management agencies for and eastern upland area are in the lagoon. A cooperative agreement private ownership (excluding tidal between the two agencies is proposed areas belonging to the State of Cali- to establish joint responsibilities fornia's sovereign lands). for monitoring, maintenance and policing of the lagoon. 12 3 These agencies will be responsible equipment and crews, are possible and for handling a number of management have been identified in the plan. concerns, including control of any mosquito problems, inspection and maintenance of any physical improvements Ongoing manual management such as culverts and pumps, removal costs (excluding scienti ic monitor- df debris, control of nuisance vege- ing costs) are estimated to be $50,000. tation, policing against trespass This amount reflects two personnel years I ~ ~and domestic animal intrusion, and im- of effort needed to manage the lagoon plementation of a scientific monitor- by the City of Del Mlar and the Depart- ing program. ment of Fish and Game. This cost would _ _ ~~~~~~~~~~be covered from each entity's operation- Financing. The implementation of the al budget. enhancement plan could cost approximat-Seraposbeoucsffnd ely $2.3 million unless identified i n g vera posibe acusitions andfund- cost savings are realized. Of this improvmenr thae beenuidentionsiad, sin- amount, a preliminary estimate of the c uimrvengtshae Wenildlnified Cosraion- ~~~csofaqisi in a enpae Board, Department of Fish and Game, the in the range of $1.5 million for 220 Conservancy, and the Environmental acres of land. (This estimate is a Protection Program on the State level. Preliminary sum which is not based upon At the Federal level, the Land and Water I ~ ~a formal appraisal. Acquisition is Conservation Fund, U.S. Soil Conservation dependent upon the availibility of funds Service's Small Watershed Act funds, and the and negotiations with land owners.) Army Corps of Engineers' Small Flood Control Public Trust interests, which must be Project funds. In addition, in-kind determined by the State Lands Commission services will be required from the Department in coordination with the acquisition of Fish and Game, the City of Del Mar, the program, may exist over a portion of California Conservation Corps, the U.S. Fish I ~ ~these properties. The identification of and Wildlife Service, and the Conservancy. such interests could reduce the ultimate Implementation Responsibilities. Pursuant acquisition costs, ~~to a cooperative agreement, the City of Del Mar and the Department of Fish and Game are designated as the lead agencies for this Site improvement costs for project. ( I ~ ~all elements of the enhancement plan could total within the range of $750,000-$900,000 if * ~~let to private contractors. Cost saving measures, including the use of State owned heavyE 13~ The plan proposes that the Depart- the initial phase of this program ment of Fish and Game, in conjunction (see page 4-24). with the Wildlife Conservation Board, 4. Assistance to the City of Del Mar in would be responsible for acquisition obtaining funding for the remaining of land needed to implement the plan phases of the program. (when funds become available); provid- ing technical assistance in designing The implementation of this pro- site improvements; and, jointly with gram will require close coordination the City of Del Mar, managing the with a number of State and Federal lagoon. agencies such as the Department of FishI and Game, Wildlife Conservation Board, The City of Del Mar will be the 22nd District, the California responsible for the appointment of Coastal Commission, the California Con- a lagoon coordinator; undertaking servation Corps, the Regional Water enhancement activities such as a Quality Control Board, the U. S. Army nuisance abatement program; coordinat- Corps of Engineers, and the U. S. Fish ing planning and implementation efforts and Wildlife Service. See Appendix AI of other interested agencies; obtain- for a list of the proposed actions by ing needed permits; and, jointly with 15 agencies. the Department of Fish and Game,I managing the lagoon. The assistance of the Conservancy is needed to implement the lagoon en-I hancement plan. Specifically, the following principal roles for the Con- servancy are proposed:I 1. Provision of technical assistance to the City of Del Mar in coordi- nating the planning and enhance- ment activities of the many State and Federal agencies involved in this program. 2. Development of an ecological monit- oring program for the City of Del Mar and Department of Fish and Game to document the effects of the en-I hancement activities and to pro- vide information for future imple- mentation phases. 3. Provision of funding assistance toI the City of Del Mar in the amount of $70,000 to cover program start- 14 up and site improvement costs for * Implementation Phasing In recognition of the need to involvement in the enhancement process. initiate this program as soon as Included tasks are: the design of the possible and the complexity of this lagoon entrance and kio~k (Area V); program, the implementation plan pro- design and placement of information signs poses that the program be implemented for the lagoon reserve; solicitation I ~ ~~in six phases. The phasing, which is of donations of materials and services; keyed to land ownership considerations, and the organization of a Spring 1980 availability of funds, and type of clean-up of litter, waterway snags, enhancement work and equipment needed, and safety hazards, in cooperation with is designed to allow adequate prep- the California Conservation Corps. aration for each enhancement activity 3. Upon the negotiation of an arrangement and realization of potential cost with the 22nd Agricultural District I ~ ~~savings. for the racetrack's overflow parking site, the City of Del Mar and DFG would Phase One establish the area as a least tern pre- I ~ ~~~~~~~~~~~~~serve (Area VI). The transfer should Phase One includes those actions be accomplished, and an alternative which can be undertaken on land al- parking site located, pursuant to 'the ready publicly owned or in the public Fairgrounds Master Plan now being pre- trust, or for which minimal acquisition pared. Protective fencing will be or lease funding would be needed, and necessary, as will the deposit of light- for which the actual work can be done colored sand to encourage tern nest- I ~ ~~largely by manual labor without the ing. Costs of fencing, supplies and need for heavy equipment. This phase equipment are estimated at $12,800. also does not require complex permits Sand is available from the Crest Canyon I ~ ~~or impact assessment documentation. alluvial fan deposited as a result of Elements in this phase would serve to heavy rains over the past two winters. build the project's local visibility Labor would be provided by the Calif- and to develop momentum for the com- ornia Conservation Corps. I ~ ~~pletion of the other phases. These 4. Following State Lands Commission find- 1 elements include: ings of public trust, the City of Del = Mar, using California Conservation Corps g I ~ ~~1. The City of Del Mar would appoint a work crews, would do the minor channel full-time Lagoon Coordinator to and water circulation improvements atE oversee and coordinate all lagoon three sites: the marsh and pond area 3 ~~~actions throughout all six phases, just east of the Camino del Mar bridge 2. The City of Del Mar would conduct (Area �ii; tne lwdrsI] at the channel a Public Involvement Program which fork (Area IX-B); and the winter marsh 1 5 ~~~would encourage continued citizen area (Area X-C). I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A 5. Following the negotiation of a and the creation of two additional lease or acquisition of the Santa bird nesting islands (Area VIII). Fe Railroad property (Area IV), Action would depend upon the negoti- the City of Del Mar and work crews ation of a low cost lease for the from the California Conservation site. The City of Del Mar currently Corps and Department of Fish and holds an option to lease the site. Game would establish a tidal basin.I Site improvements would include Work tasks include repair of some earth movement and installa- levees and clearing of vegetation tion of a pipe with a flood control from the bottom of the pond, the cre-I gate connecting the new marsh to ation of two bird nesting islands, the west channel. Earthmoving the filling of the marsh with 70 acre- costs are estimated at $30,000 and feet of water from the San Dieguito pipe installation costs at $17,000 River or from winter runoff, andI if let to private contractors. the erection of two windmills to pump in ground water to replace water Phase Two loss. Phase Two includes the develop- Site improvement costs are esti- ment of the northern tidal basin and mated at $5,000 for the rental of equip- nesting island (Areas IX-A-D), which ment (this phase can use some of the would be possible upon public owner- same equipment that would be used in ship or control of the Del Mar 88 Phase Two) and $17,200 for the two property (101.7 acres). This phase windmills. The California ConservationI would require heavy equipment, such Corps and DFG would provide work crews as trucks, swamp cats and possibly to assist in construction. The City a dragline. Tasks would include the of Del Mar and the Conservancy haveI reconstruction of levees and excava- applied for funds from the California tion of channels connecting the tidal Environmental Protection Program. basin with the south channel, and creation and enhancement of a least Phase Four tern nesting island. Site improve- ment costs are estimated at $200,000. The actions in Phase Four would It is proposed that the Wildlife take place when the Moshtaghi propertyI Conservation Board carry out the is under public ownership. The Wild- acquisition and fund the site improve- life Conservation Board is currently ments. pursuing acquisition of this property.I These activities would also involve Phase Three the use of the heaviest equipment, This pase ivolvesthe cnver-probably including a suction dredge. sion of the sewage oxidation pond Work tasks would include the Ira ~~~presently owned by the City of San creation of the tidal basin, installa- 16 ~~~~Diego to a freshwater pond and marsh tion of a pipe connecting this basinI with the northern tidal basin, dredging of the Fishhook channel, and enhance- ment of created islands for least COMPARISON OF SAN DIEGUITO LAGon--'BEFORE AND AFTER' ENHANCEMENT tern nesting (Areas X-A-C). The cost of these improvements is estimated at FEATURE BEFORE f AFTER $270-400,000 (depending on the type of equipment used). These costs PLANNING AREA 650 Acres Lagoon Reserve - 225 Acres Lagoon Buffer Area - 200 Acres could be met from funds from the Wild- Fairgrounds/Racetrack - 225 Acres life Conservation Board, The Department of Fish and Game and the Federal Land TOTAL OPEN WATER About 31 Acres About 60 Acres. (Measured at one foot above Sea Level--- and Water Conservation Fund. The approximate Sill) Phase Five ,NUOFLATS About 3 Acres About 8 acres, This phase involves the upland PICKLE WEED SALT MARSH About 117 Acres Same (some losses will be replaced and habitat enhancement including clean- revitalized). up and removal of debris from upland FRESHWATER MARSH Isolated areas, including winter rain About 14 Acres (pond and marsh) in areas (primarily in Areas IX and X) ponding area addition to existing areas and replanting them with native vegeta- tion. This activity would be carried UPLAND VEGETATION About 325 Acres About 292 Acres out by DFG pursuant to its regular management duties once the land is SANo DUNES About 4 Acres About 4 Acres (one--or less--in under public management. preserve) DRY SAND FLAT About 26 Acres About 30.5 Acres Phase Six (includin� least tern areas) This phase involves the dredging of the main channel of the San Dieguito River and the northern portion of the South Channel to the Grand Avenue bridge for flood control purposes and to enhance the lagoon's tidal flushing. Cost is estimated at $250,000 which is potentially available from the Soil Conservation Service's "Small Watershed Project" funds or from the Corps of Engineers' "Small Flood Control Project" funds. A substantial lead time (2 to 4 years) is necessary to secure aid from these programs. E 17ym land use regulations Adequate land use regulations are and zoning for railroad purposes along essential to ensure that appropriate the Santa Fe Railroad tracks. land use, structural design and erosion control measures exist to pro- The fairgrounds/racetrack complex tect the San Dieguito Lagoon from the is included in an FR Zone, leaving impact of development occuring in and development decisions up to the 22ndI adjacent to the lagoon. The develop- District Agricultural Association ment of adequate land use controls is which owns the property. No change a condition precedent to and indepen- is proposed in the FR designation, but dent of implementation of the pro- it is recommended that recreation-oriented posed enhancement work. The proposed uses in that zone shall be limited to land use regulations (see Chapter Five) those proposed in the 22nd District include zoning within the lagoon area Master Plan, as certified by the CoastalI and provision for a buffer area sur- Commission in the City of Del Mar's LCP. rounding the lagoon. Zoning recommendations are alsoI It is recommended that the Local made for portions of the project site Coastal Program retain existing zoning within the City of San Diego and the for most of the lagoon areas within County of San Diego jurisdictions. It the City of Del Mar. This includes is recommended that the County's agri- Floodway (FW) for the area between cultural area immediately north of the San Dieguito Drive and Jimmy Durante fairground/racetrack complex and the Blvd. and along the west channel of City of San Diego A-1-10 (agricultural,I the San Dieguito River, which prevents allowing one dwelling per 10 acres) any uses which would be damaged by or zoned area immediately east of the cause restriction of flood flows. racetrack be annexed to the City of DelI Mar and zoned with Del Mar's designation, The southern side of the river's permitting only uses related to the west channel is zoned North Commercial recreational facilities at the race- (NC), allowing low-intensity commercial track. uses. While the majority of this area should be maintained in this zoning, It is recommended that the Flood- in order to allow the implementation way (FW) zoning for the floodway areaI of the proposed tidal basin on the in the City of San Diego bo, retained. Railroad parcel, that parcel is recoin- The A-1-10 zone at the southeastern mended for Public Park.(PP) zoning. end of the project area will be retainedI until such time as public acquisitions Zoning within the City of Del are completed. Finally, it is recoin- Mar also includes low to medium density mended that the zoning on the hillside 18 residential uses on the slopes at the south of the lagoon be changed to reduceI southwestern edge of the project area, the residential density currently permitted to a maximum of one unit Design criteria and development per two acres in accordance with recent controls to be applied to the buffer Coastal Commission permit decisions. area Were based on the following criteria: A 225-acre ecological reserve 1. preservation of the natural habitat would be created, with a surrounding values of the reserve; buffer area of about 200 acres. The 2. protection of the water quality of 225-acre fairgrounds/racetrack complex , the reserve; and associated commercial facilities 3. preservation of the visual resource are designated for recreational and values of the lagoon and its view- I ~ ~visitor-.serving uses. Ecological shed; and reserve status is proposed for San 4. protection of the scenic bluffs. Dieguito Lagoon to allow site altera- tion for enhancement purposes and to protect the lagoon from future develop- ment and unrestricted human access. The proposed ecological reserve would I ~ ~include the lagoon channels and the open wetland and upland area between the north channel and the Fishhook. A buffer area would be designated on either side of the lagoon, to protect the lagoon and its wildlife resources from human intrusion, sedi- mentation and the visual impacts associated with development, and to protect development from flood hazards. I ~ ~The buffer area would consist of the narrow strip of land between the lagoon and development to the north and a wider area between the lagoon and the bluff tops on the south and west. The northern buffer would remain free of structures, while the I ~ ~southern buffer strip would contain existing and expanded commercial and low-density residential uses, which I ~ ~would be sited and designed to control undesirable impacts on the lagoon. The remain-der of the planning area,E between the northern buffer strip ~~~~n iadlaVlewolbersvd for recreational uses associated withE the racetrack/fairgrounds complex. environeta assnent of the program This Lagoon Enhancement Plan Additional information on im- was found on November 19, 1979 by pacts is found at page 1-7. The the City of Del Mar City Council actions proposed to implement this to be categorically exempt from plan are listed in Appendix B with the requirements of the California assessments of significant impacts. Environmental Quality Act (CEQA).I Specifically, Section 15107 of the California Administrative Code states that a Class 7 exemption covers "actions taken by regulatory agencies as authorized by State Law or local ordinances to assure the maintenance, restoration or enhancement of aI natural resource where the regula- tory process involves procedures for protection of the environment... Construction activities are not included in the exemption". With the City of Del Mar acting as the "regulatory agency", and the pro- ject designed to conform to the California Coastal Act and the Coastal Conservancy Act, this planI accomplishes the goals of the California Environmental Quality Act.5 To evaluate future construction activity, a "focused EIR" will be prepared by the lead agency on theI environmental impacts of such activi- ties. However, preliminary environ- mental assessments have, been includedI throughout the preparation of this program in order to ensure their 20 consideration in the planning process. I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~P I ~~~~~~~~~~~~~C * ~~a 0iglolgo I~ ~rorn inrduto programn backgroundU The San Dieguito Lagoon Enhance- In 1974 the City of Del Mar3 mvent Program is a joint effort of the appointed a citizerns' Lagoon Preservation State Coastal Conservancy and the City Committee to prepare a specific plan for of Del Mar to restore and enhance the lagoon which was reported to the City a degraded wetland on the San Diego Council in April 1975. In the following coast. This program is a "resource year, the California Coastal Act was enhancement plan" as established in passed, requiring local governments to the Conservancy's enabling act and is p~repare LCPs for those portions of theirI a component of the Local Coastal jurisdictions within a designated coastal Program (LCP) prepared by the City of zone. To begin this process the City Del Mar in accordance with the Cali- contracted with the Coastal Design GroupI fornia Coastal Act of 1976. at California State Polytechnic University, Pomona, to develop a series of conceptual The history of this program goes design alternatives for the enhancement back to 1974 when the California of the lagoon. The citizens' committeeI Department of Fish and Game and the served as advisors for this study. The federal Bureau of Sport Fisheries and "preferred alternative" which resulted from Wildlife (now the Fish and Wildlife this effort was endorsed by the City andI Service) published a report recommend- became the starting point for the prepara- ing San Dieguito Lagoon and 18 other tion of this program. coastal wetlands for top-priority ac- quisition in California. The Depart- Many of the citizens on the 1974 ment of Fish and Game (DFG) in 1976 committee were re-appointed to the Lagoon issued a more detailed study which Planning Committee in 1978 as preparation recommended the lagoon be established of the City's LCP was begun. The new groupI as an ecological reserve and with the was expanded to include property owners and restoration of tidal actions to create others to ensure balanced input. amarine environment. In 1975 theI California Coastal Zone Conservation In the fall of 1978 the City found that Commission completed the California it had insufficient funds to complete a Coastal Plan which designated the thorough study of the lagoon and requested lagoon as a special study area. assistance from the State Coastal Conservancy. 1-2 A planning grant of $30,000 was awarded The implementation plan in Chapter Four' in November 1978 by the Conservancy describes appropriate means for carrying which, with an LCP-related grant of out the desired site improvements, rec- $8,000 from the Coastal Commission, ommends areas for acquisition, outlines enabled City and Conservancy staff to management responsibilities, and proposes I ~ ~begin the consultant selection process. appropriate funding sources for each In April 1979 Sea Science Services, Inc. phase of the enhancement program. The was selected as the primary consultant lagoon land use regulations establish the for engineering and hydrological zoning and other ordinance control neces- studies, with Pacific Southwest Bio- sary to protect the integrity of the logical Services, Inc., providing lagoon as part of the City's LCP in Chapter biological and impact assessment. Five. I ~ ~Throughout the following months of research the citizens' committee, the Department of Fish and Game, the U.S. These chapters have been based upon I ~ ~Fish and Wildlife Service (USFWS), a substantial physical inventory of the as well as numerous representatives lagoon's natural and human-made resources of local agencies, contributed out- which are summarized in Chapter Two. standing technical advice and many In addition a substantial amount of hours in meeting participation. supporting technical material is included in appendices and the consultants' report The rsultof ths log planingwhich, can be reviewed at the Del Mar I ~ ~process is the present program which Planning Department and the Conservancy is based upon the preceding work by office. DFG and Cal Poly planners, but which I ~ ~presents in much greater detail the The program is based upon the premise methodology necessary to make the that the regulatory measures of Chapter project an implemented reality. Five will adequately protect the lagoon from inappropriate uses. As land ac- . I ~ ~~This document has three major quisition funds become available, and components: Chapter Three, the necessary approvals are obtained, the lagoon enhancement plan, identifies enhancement work may begin. appropriate site alterations to en- hance the area's environmental quality. Provisions for rec- * ~~reational access and vehicle circul-- ation are also made. 1-3 program significance Coastal marshes and estuaries are among the most jproductive and valuable ecological systems in California. In their <~,~p~~53~~ natural condition they produce large quantities of food for both marine and terrestrial organisms along the coast and provide essential habitat for hundreds of fish and ,ildlife species. Marine fish enter coastal wetlands to feed and also use them as breeding and nursery ? be Ad grounds. According to the Council on Environmental Quality (1978) about one-half of the commercial fish and shellfish harvest on the Pacific coast is dependent on coastal wetlands. The primary wildlife groups dependent on California coastal wetlands are a large variety of migratory shorebirds and waterfowl, which spend the winter or stop for shorter periods in these areas during annual migration along the Pacific flyway. Several million waterfowl frequent California's coastal wetlands annually. In addition, many species of wading birds, other water- associated birds, and raptors (birds of prey) are supported by coastal P,- t", *,_-*. wetlands. Five endangered bird and mammal species are totally dependent on these areas. (see "endangered species" in Glossary). 1-4 San Dieguito Lagoon is one recreational and educational of the few wetlands remaining on opportunities; and provision for urban the Southern California coast, land'uses. an area which has lost 75 percent of its valuable wetland acreage This program also can serve as I ~ ~since the time of European settle- a model for other wetland enhancement ment and which continues to be efforts along the California coast. subject to intense pressures for The preparation of this document has development. San Dieguito Lagoon required the creation of new concepts itself has been reduced from 600 and methodology for which no proven to 200 wetland acres, and suffers or documented precedents exist. from a history of sewage discharges, Therefore, much of this program is water diversions, sedimentation, experimental. As a result, a phased human and pet intrusion and other implementation process was developed disturbances. In spite of the (Chapter Four) to permit monitoring I ~ ~degradation of its habitat of results and further plan refinement. values, the lagoon remains a as increasingly difficult levels of highly significant wildlife area work are initiated. This program, which has been identified by the then, is also a means to increase the California Department of Fish understanding and state-of-the-art and Game and the U.S. Fish and of lagoon and wetlands management in Wildlife Service as one of the California and can become a vehicle I ~ ~19 coastal wetlands of top which leads to a higher level of priority for acquisition. activity by State and Federal agencies in the preservation and enhancement The lagoon's ecological of our invaluable wetland resources. significance and restoration potential have also been recog- nized by the California Coastal Commission and the Cities of San Diego and Del Mar. San Dieguito provides the oppor- . I ~ ~tunity to balance, within the context of the 1976 California Coastal Act, a complex array of demands: for protection and U ~~enhancement of the lagoon's0 biological productivity, species and habitat diversity, and aesthetic quality; for elim- ination of health hazards and flood hazards; for provision of - objectives Establish appropriate land use, structural design, and erosion controls in and around the From the existing lagoon doc- lagoon. uments (by Cal Poly and DFG) and the Secure public ownership orI early research for this program, a control of lands in the set of policy objectives evolved to lagoon; guide the definition of enhance- Protect the existing environ-I ment actions for the lagoon. The mental value of the lagoon; overall goal of this program is Enhance water circulation and to meet the intent of Section 31008 tidal flushing in the lagoon; of the Public Resources code, which Improve or create a variety ofI describes a "Coastal Resource habitats to increase wildlife Enhancement Project" as being diversity and ensure protection "actions taken by a local public of endangered species;I agency or a state agency necessary .Facilitate recreational access, to restore, as nearly as possible, vehicle circulation, educa- degraded natural areas to their tional and scientific activitiesI original condition or to enhance and any coastal/water dependent the resource values of the coastal uses which do not significantly zone." This activity must of diminish resource values; course also be conducted in a Identify funding and manage- manner compatible with the Coastal ment mechanisms to achieve the Act of 1976. cost-effective and timely com- pletion of site development work;I The program objectives which Conduct adequate scientific have guided the development of monitoring of the resources and Lne lagoon enh'arIuement actions policiui of human dctivities toI are as follows: protect the lagoon from adverse impacts. U ~~environmnental impact I assessment On November 19, 1979, the Del Mar City SINFCTADEEIMCS Council found this plan to be categorically exempt from the administrative requirement$ As proposed, certain aspects of the of the California Environmental Quality construction of the channels and tidal Act (CEQA). Specifically, Section 15107 basins willresult in significant adverse of the California Administrative Code environmental effects which cannot be states that a Class 7 exemption covers avoided, but can be mitigated if the project ~~~'acion taken by regulatory agencies as is implemented. No impacts are considered authorized by State law or local ordin- irreversible. ances to assure the maintenance, restor- ation or enhancement of a natural As the result of these activities, there resource where the regulatory process will be a temporary loss of some of the involves procedures for protection of existing pickleweed. Further, soil excava- the environment..." Construction activi- tions in or near a waterway will result in ties are not included in the exemption. sedimentation. This work will also disturb benthic (bottom-living) organisms. Some of With the City of Del Mar,actin-g the excavation work will require the I ~ ~~as the "regulatory agency", and'the construction of temporary roads to permit project designed to conform to the truck and dragline access. The use of California Coastal Act and the suction dredgers could create serious Coastal Conservancy Act, this plan problems of excessive soils removal (to is consistent with the goals of permit boat movement), and storage and the California Environmental Quality disposal of the spoils. * ~~~Act. In terms of future construction MITIGATION AND BEEFITS . activity a "focused EIR" (see glossary) I ~ ~~will be prepared by the lead agencyThsor-emavsefecsf on tuhe spctificies.vTirocumenta ipcts excavation work in the lagoon should be .eome suhe bacites.ehi dofcaumatrentiron- offset by the overall long-term effect of I ~~~bmenthe bassesset ofor "ather environ- the project, which is to increase the0 mentalassessent" fr the agoon.biological productivity and diversity of Preliminary environmental assess- the lagoon. The increased tidal0 I ~ ~ments have been conducted throughout the flushing and water circulation will im- preparation of this plan in order to ensure prove water quality, reduce mosquito consideration of impacts during the planning breeding and enhance the lagoon's scenic I ~ ~process. These assessments are noted in quality. 1-7~ Appendix B and are summarized below. The short-term loss of pickleweed signing the work in sequential stages is will be offset by the revitalization to permit full evaluation of each activity of the remaining pickleweed and the to occur before and after it is accomplished.I establishment of new salt marsh. Any adverse consequences can and must be Pickleweed is known to recover quickly resolved before the next phase begins. and can be expected to colonize the new In addition, this prudent approach to im- areas suitable for marsh within a few plementation offers flexibility in later years. refining the design concepts as new Sedimntaton an botom ditur-information on methodology becomes available. bances will be held to a minimum to Alternatives to those planning accomplish the program design. The use guidelines can be identified as the phase of heavy dredgers will be avoided in is initiated, under the following process:I all phases but the last. It is antici- The lead agency will solicit bids based pated that excavated soils will be on the policies and intent of this plan. transported directly to the racetrack/ The responding engineering firms will fairgrounds for use there. Excava- submit their proposals for the work which tion work must be preceeded by a EIR/EIS may include revisions for scope of excav- which will address in detail the issues ation and equipment to be used, etc. The of sedimentation, bottom disturbances, lead agency will select the most appropriate impctsof ccesroads and spoils response but, before initiating the contract, dispocsofacces will prepare and circulate a focused EIR disposal. ~~~~~~~describing the engineers proposal and its ALTBMTIVES ~~ ~~ relationship to this Lagoon Plan. The ALTERNPJIVES ~~EIR review and comment process will then clarify how the contract and the work If there is no project, the lagoon, are to be executed. as is, would continue to have resource values but its productivity would not Hence, the phasing process permits be achieved and deterioration will the identification alternatives and mod-I continue. Management and monitoring ifications, which reflect current would be nearly non-existent. For economics and the state-of-the-art in all phases where earth movement is wetland management. needed, a conceptual design has been proposed, as has the equipment which seems most suited to the work. f The entire project has, in effect, a built-in mitigation pro- cess which results from the phasing of the six major construction ac-I tivities. A primary reason for de.- I~~~~~~~~~~~~~~~~~~~~~~~~~flAbna I~~~~~~~~~~~~~~~~~~~L I~~~~~~~~~~~~~~M I~~~~~~~~~~~~~~~~~sn 0ig lo a- ~~~eisigev r nen,-., introduction I ! I This chapter presents an ecologi- cal and physical inventory of the San Dieguito Lagoon which has been prepared to a large degree specifically for this plan. This inventory was based I on existing information prepared by the Department of Fish and Game (DFG) and Cal Poly Pomona, supplemented by additional research. A detailed discussion of the inventory data can be found in the consultants' report, available at the City of Del Mar and the Conservancy office. Such an inventory is a vital tool in identifying the design re- quirements for site construction work. Physical and environmental para- meters need to be identified in order to guide the development of project design and work tasks. This process satisfies a major intent of the California Environmental Quality Act, i.e., the avoidance of adverse impacts through adequate planning, data I collection and mitigation as required. 2-2 I the. lagoon setting LTIIN The San Diego coast region The planning area (see map, page 2-6) is characterized by a mild ("sub- encompasses approximately 650 acres tropical Mediterranean") climate of lagoon channels and wetlands, surround- and an attractive coastal landscape. ing lowlands, and bluffs. The area The broad terraces of the Peninsula is bounded by the ocean shoreline to Mountain system, which run parallel the west, Interstate 5 to the east, to the coast, are cut by several Via de la Valle to the north, and a rivers, most of which form a small line of bluffs broken by Crest Canyon lagoon at the mouth. San Dieguito to the south. Lagoon is one of the smaller remain- ing coastal wetlands in the region. HISTORY Most of the San Diego County San Dieguito Lagoon began as a wetlands have been areatlv reduced large, deep ocean embayment, which in size and, have poor water circulation probably extended inland several miles partially due to filling and construc- as far as the present location of tion of transportation corridors. El Camino Real. Over the last 12,000 Water quality has been reduced by years the embayment gradually filled continued use of wetlands for sewage with river-borne silts and marine sands. effluent disposal. There is a con- Today the lagoon area is largelv composed spicuous shortage of healthy salt of marsh or grassland-covered silt marshes containing extensive stands and clay sediments, cut shallowly by of cordgrass (Spartina foliosa) narrow tidal channels. The main and pickleweed (Salicornia spp.) vege- channel system consists of a single, tation in the region. east-west-running channel with a fishhook- shaped south fork. A narrow strip of San Dieguito Lagoon is located salt marsh borders the western portion on the northern edge of the City of of the lagoon, broadening to the east Del Mar, a small residential community where the channel forks. The total wet- about 20 miles north of San Diego Bay. land area is approximately 200 acres. Del Mar is the southernmost of six small but rapidly growing beach communi- The environs were occupied for ties in the northern portion of San Diego thousands of years by California Indians, County. To the south and east, the who utilized shellfish and other wildlife City is bordered by the City of San from the area. Archaeological findings Diego; to the north, by the unincorporat- at San Dieguito indicate a human occupancy ed community of Solana Beach. of nearly 50,000 years. Little is known 2 I 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- OCEANSIDE ESCONDIDO Agua Hedionda Sutherland Res. source: Lagoon ,.. _-*elev. 5700' Julian Lake Hodges Ramona SAN DIEGUITO Del Mar 0 5.3 10.6 MILES 1 REGIONAL SETTING SAN DIE-O SAN DIEGUITO WATERSHED 2-4 about the condition of the lagoon at had adverse effects on the lagoon. In the time of Spanish settlement, but the last two years an alluvial fan some early accounts describe the at the mouth of Crest Canyon has I ~area as very green, with flowing streams grown to a size of several acres, or ponds of water, indicating that covering the wetlands in the southern more fresh water once flowed into the curve of the Fishhook channel. U ~lagoon. Farming activities at the lagoon At the turn of this century, had to be abandoned in the late 1930's the lagoon consisted of a 600-acre due to degradation of groundwater expanse of salt marsh, tidal channels, quality caused by overdraft and the and freshwater-brackish marsh extend- effects of Lake Hodges Dam. ing nearly two miles inland. The San Dieguito River was reported as one of Extensive landfilling for the only three streams in the- area (the 200-acre Del Mar racetrack and fair- others being the Santa Margarita and grounds, for major highway and rail the Soledad) which were able to keep crossings of the lagoon, for the Del Mar narrow channels open year-round Airport (now abandoned), and for through sand deposits at the river mouth. various smaller developments-greatly The Ilagoon has undergone many prism of the, lagoon. During normal changes in the last eighty years. rainfall years, San Dieguito lagoon The completion of Lake Hodges and remains closed to tidal action for0 Lake Sutherland dams reduced the much of the year. 16 effective drainage basin of the lagoon from 345 to 43 square miles, reducing Population growth in the northern aquifer recharge and freshwater habitat portions of San Diego County has in- in the lower valley and eliminating creased substantially in recent years c the periodic river floods that had and is expected to continue growing previously helped to keep the lagoon at a rapid rate. If implemented with- channels free of silt and the lagoon out controls, continued development mouth open to tidal exchange. in the watershed will contribute to sedimentation and pollution in the 0 I ~~~Water quality problems in the lagoon. closed lagoon were aggravated for many years by discharges of sewage effluent into two oxidation ponds in the eastern portion of the lagoon, a practice which was discontinued in 1975. Sedimentation NM * ~from the disturbed watershed has also 2-65X V.~~~~~~~~~~~~~~ Sofa~~~~~~~~~~~~~~~~ Bec 7prsn niromn /Jr, I.lWT, B~~~~~~~~~~~~~~~~~~~~~01 ~~~~ " ~~~~~~~~~ /~R.g De,*~l Marg Aft IL I5 san dieguito lagoon enhancement olan C1ity Of Del Mar1. CalltOrrnta -State COOaStal Conservancy3 2-6I natural resources Habitat Types Belding's Savannah Sparrows also The major habitat types in the forage in this habitat. Low eleva- San Dieguito Lagoon study area are: tions could harbor eelgrass (Zostera) open water, mudflats, coastal salt or cordgrass (Spartina foliosaF, marsh, fre shwater -brackish ma rsh, salt neither of which is now found in flats, maritime sage scrub, disturbed the lagoon. upland vegetation,sand dunes, and sterile ground (parking lots and other Marsh habitats (excluding salt barren areas). ~~~~~~Marsh habitats (excluding salt barrenI~ areas). ~~flats) cover approximately 18% of *bthe lagoon area (about 49 acres). Two Open water having a depth of over the lagoon area (about 49 acres). Two 6 inches at high tide covers about major types of marsh occur at the 38 acres, or approximately 14% of the lagoon: castal salt marsh and salt marsh occupies the bulk of the total lagoon area at present. This fshaltemar ccie marsh. Coastal habitat is used by aquatic invertebrates, uist e bl of the . I ~~~~~~~~0 fish, aquatic snakes, turtles andof the enhancement plan several bird species. Some larger and is the focus wading birds feed in the shallower The salt marsh as mapped is parts ha bitat. This area , use- mostly Pickleweed (Salicornia virginica), E parts of this habitat. This area, use- ThEatmrha apdi ful as an escape area for birds, Alkali Heath (Frankenia g ifolia) � includes steep and gently sloping shores. Alkali Heath (Franken ia grandifolia) and Shoregrass (Monanthochl oe 1littoral i s). Shoreline mudflat areas, which The vegetation represented by the se are covered with shallow water (0-6 plants is characterized here as a inches in depth) at high tide but closed-lagoon low marsh". exposed at low tide, cover approxi- Although this association is m ately 3 ac res, or 1% of the total typical of coastal salt marsh C lagoon area. At high tide, this habitats in Southern California, habitat is used extensively by smaller several expected species are lackingi * * * ~~~~~~~~~several expected species are lacking fish or fry, aquatic invertebrates, or have yet to be detected in the aquatic snakes, and a variety of birds, San Dieguito Lagoon system. These including ducks, waders, and shore- ...._ i ncluding ducks, waders, and shore- plants include Spartina foliosa, Batis birds. Invertebrates (e.g. worms, _____ . .- ~~~~~~~~maritima, Salicornia bigelovii and f clams, and crabs) experience heavy Cordylanthus maritimus. All of these predation at low tide from birds and Cordylanthus maritimus. All of these M at high tide from fishes. This plants are found in salt marshes north habitat is very important to shorebirds ap h o animito doon o and south of the San Dieguito lagoon, so for feeding and resting and to many geographical rangelimitations do not fothr typesdofbirds asna resting anman y explain their absence from the lagoon. other types of birds as a resting area. 32-7 vegetation I habitatsI Legend3 El ~~~~7jj open Water ~~~/ ~~~Salt Marsh E~Fresh Water Marsh -_j ~~~~~~~~~Phragmltes Juncus Mudliats EZISalt Flats LI]Disturbed Grassland Disturbed Area 111Escaped Exotlcs3 LI]Sterile A - ~~~~~~~~~~~~~~~~~Coastal Dune \\\\\ LIZISand Delta [X]inland Sage Scrub NM~~~I- san dieguito lagoonenhancemnent -plan City @ of D Mar. 04aiIforrnl State Coastal coflservapey3 2-8 U ~~It is presumed that the high degree vegetation also occurs on the south side of disturbance in the lagoon accounts of the channel west of the Jimmy for this lack of certain wetland Durante Bridge; the source of fresh I ~ ~plants, but the precise cause-and- water for this stand is unknown. effect linkage is unclear. The low-lying area east of the Fish- Marsh vegetation dominated by hook channel is periodically flooded Salicornia harbors Belding's with freshwater runoff during the Savannah sparrows, song sparrows, and winter. The deposition of the Crest a few nesting ducks but is otherwise of Canyon alluvial fan has impeded ~~limt dvletmotainsce. drainage of the area, resulting in Raptors hunt over this area where a salownwaer pereaois ofutnilize Thaaist number of insects and small mammals can s hlow waebrairs, uinlizding vabbletyucs I ~~be found. Channel banks at the edgeofbrsinldgdaleduk, of this habitat are often quite steep shorebirds and other species. ' and may allow rapid escape into the Salt flats, or closed-lagoon "high 3 ~water by waterfowl surprised by predators.mas"copieprxmtly6(1 Decomposiion prodcts fromacres) of the total lagoon area. Most Decmpsiio prdcsfo * ~~Salicornia and associated vegetation of the high marsh occurs south of Grand * ~~when flushed into the lagoon channels Avenue, in the eastern portion of the provide nutrients for invertebrates lagoon. This habitat is a mixture of and some fish. open salt flats and clumps of Glasswort0 (Salicornia subterminalis). Portions of In som area mars vegeationthe high marsh have been invaded by non- Insomied wihareasse marsh vegetfatio n native grasses, particularly Hordeum. * ~ ~i m iedweingthgrses anduality oflhbiatso Killdeer and ducks are occasionally seen *~lwrn h q ualiysfhait speies in these open areas but probably derive marsh species. ~~~~~very little nutritional or other value * ~~~Freshwater-brackish marsh, mapped from them. Since the salt flats are * ~~as Freshwater Marsh, Phragmites, or not extensive and are generally inter-0 ~Juncus, occurs at several sites in the spersed with vegetation, they provide study area. Cattails (Typha latifolia) only limited isolation from surrounding dominate a low area along the San vegetated areas which may harbor predators. 0 I ~~Dieguito River, under the Interstate 5 In other lagoons exhibiting expansiveE bridge. West of the railroad tracks, flats, terns and shorebirds may rest in leakage from a water main sustains an the protection of this open terrain. interesting assemblage of aquatic and marsh plants, dominated by the sedge, Cyperus laevigatus. Freshwater marsh 29_ Upland vegetation comprises The sector west of the highway is approximately 50% (135 acres) of the in a more natural condition but foot total lagoon area. Two habitat types traffic, littering and flotsam deposition are included in this general category: during storms and high tides have de-3 disturbed, mostly non-native vegetation graded the area. Wind action is still (mapped as Disturbed Grassland, adequate to maintain the dunes and with Disturbed Area, or Escaped Exotics), and adequate foot traffic control the site native maritime sage scrub. Disturb- will soon recover. Sea fig (Carpobrotus), U ed areas of the lagoon are mostly in ragweed (Ambrosia), and sand verbena the eastern portion of the study area, (Abronia), are taxa which characterize where previous light industry, land the vegetation of the dunes here. filling, and an oxidation pond for sewage treatment are or were located. Since the dunes at San Dieguito are Due to previous human activity, undisturb- limited in area and subject to consider- I ed native sage scrub vegetation occurs able human impact, they are of limited only near the southeast boundary of the value to wildlife. However, a variety lagoon. of native plants occur in this area, and the Globose dune beetle, a rare Numerous species of upland birds, species, is known to inhabit this kind mammals, reptiles and amphibians of environment. In earlier times, utilize both disturbed and native up- when human disturbance was low, leastI land habitats extensively. The scrub terns nested in large numbers in such vegetation in Crest Canyon and the small dune habitats. section of relatively undisturbed land east of the Canyon probably Sterile ground (parking lots and serve as refuges for a variety of other barren areas) occupies approximate- animals (e.g. several larger mammals, ly 10% (27 acres) of the lagoon area. snakes, and lizards) and as a source The major wildlife use of these areas of animals that regularly move into the is for resting by gulls, terns and lagoon area. occasionally a few other species. Kill- deers forage here and least terns haveI Sand dunes comprise approximately attempted to nest. During rainy periods, 1% (3 acres) of the total lagoon area. ponds form in depressions in these areas, Dune vegetation occurs on the south and increased shorebird and puddle duck side of the San Dieguito River channel use occurs. Protection of these flat, along Camnino del Mar. The sector east open areas will likely increase numbers of the highway has been disturbed signi- of least terns and shorebirds nesting ficantly in the past but, because of in the lagoon. recently stabilized soil, now appears to be recovering as Sage Scrub. 2-103 Enhancement Needs and Constraints Flora It is apparent from the relative per- The flora of San Dieguito Lagoon centages of the major habitat types at is generally dominated by species that San Dieguito Lagoon that mudflats, are adapted to the relatively high ponds, sand dunes and salt flats are salinities and temperatures that frequent- in relatively short supply. In order to ly occur in the periodically hypersaline achieve greater habitat heterogeneity, lagoons of Southern California and which generally corresponds with greater Northern Baja California. Past disturb- animal species diversity, it appears ance has left little of the original desirable to increase the relative marsh, and the diversity of plant percentage of the rarer habitat types species usually found in such environ- at the lagoon. Sand dune habitats are ments is very low. In fact, San Dieguito very difficult to create in the lagoon, had the lowest species diversity of any I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I and sizable salt flats are both difficult of the San Diego County lagoons studied to create in such a small lagoon and in the late 1930's. Although 99 plant are also of limited value to wildlife; taxa have been inventoried for the therefore, mudflats and ponds are San Dieguito Lagoon by the present considered the most important of these study, only 57%' of the species are habitat types to create as part of the native component, only 16 taxa (28%) lagoon enhancement program. Because are associated with the coastal salt marsh the western portion of San Dieguito habitat remaining in the lagoon. Lagoon has been restricted to a relative- ly narrow passageway by channelization and encroaching development, most of Two sensitive plant species occur 16 the desirable habitat expansion must at San Dieguito Lagoon. A population occur in the eastern portion of the of Prostrate Hosackia (Lotus nuttallianus) lagoon. occurs in the dune habitat west of Camino del Mar. This species is considered rare and endangered by the California Native Plant Society (CNPS) due to habitat destruction and limited geographical range. About six plants occur in the population, and these could increase in number if the dune area is C protected in the future. 2I11 m I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2-11 I S~~~~~~~~~~~~~~~~~~~~~~~~~~. Another senstive plant species of the lagoon is the sea dahlia (Coreopsis maritima), an attractive herbaceous perennial sunflower which occurs on sea bluffs from Leucadia, California to San Qu.intin, Baja California. This species is rated as rare but not endangered by the CNPS though it is threat- ened by sea bluff development. W]ithin the study area, only seven plants occur; these are found on the west side of the railway embankment and just west of the Crest Canyon sand delta. Enhancement Needs FaunaI The relative paucity of native plant species at San Dieguito Lagoon indicates the BIRDS extent to which the lagoon has been disturbed by trampling, landfilling, water pollution, A total of 118 bird species (both loss of tidal flushing, and other development- upland and water-associated birds) have been related impacts. To enhance the health and sighted at San Deguito Lagoon. Several diversity of the lagoon's vegetation, it is additional species are also likely to frequent desirable to control these impacts, and in the lagoon periodically. An example of particular to improve tidal action in the the variety of birds that may utilize San lagoon, since this would allow cordgrass Dieguito Lagoon during the year is (Spartina foliosa) and other intertidal plant provided by counts recorded for San Elijo species beneficial to fish and wildlife to Lagoon (three miles north). Over 190 return to the lagoon. In addition to enhanc- species were recorded there during recent ing overall plant species diversity, it is censuses beginning in 1973. A majority desirable to protect the two rare species of these species are potential visitors I which now occur at the lagoon. or residents in San Dieguito Lagoon. The birds considered to be ofI primary concern in San Dieguito Lagoon are listed with their major habitats and foods in the consultants' report. The habitat type most heavily used by birds at the lagoon is shallow water/mudflat, with several other habitat types having fairly equalI secondary levels of use. 2-12 I Two endangered bird species are found at San Dieguito Lagoon, and a third could inhabit the lagoon if tidal action were restored. These three species are briefly discussed below. Belding's Savannah Sparrow This subspecies has suffered a decline in recent years due to the destruction of its sole habitat type by development and dredging projects. The total population is estimated at 1000 to 1600 pairs. The bird is essentially restricted to coastal Salicornia salt marsh where it both nests and feeds. Feeding may also E occur in sand dunes, beaches and mud- C flats near its Salicornia home. Its diet consists of small invertebrates inhabiting marsh vegetation and mudflats. mm In the San Dieguito Lagoon, this species was found to inhabit the several available stands of Salicornia. In all areas, these birds seem to occur in groups rather than evenly throughout the existing suitable habitat. Due to the secretive habits of this bird, as well as the likely occurrence in the area of non-breeding birds, the popula- tion size may be somewhat underestimated. E Expansion of Salicornia marsh should m lead to an eventual increase in numbers of this species. 2-13 m --i ... .re/endangered species* ~i][If~f~nflc> ~ C Xlating Habitats) ~~~~~ ~~~~Legend 'IT]' ~~Least Tern Feeding Areas 4/ ~~~~Least Tern Historical Nesting Areas Least Teon Roost ing SitesI =1BlIngP's Savannah Sparrow FeeingAreas Belding' SravanhSarw Nestings Aravanhspro san dieguito, lagoon enhancement plan- City of Cla titr. Calflornta -State Coastal Conservancit 2-14 California Least Tern This species formerly occured river flows eliminated the dike I ~ ~in large numbers in coastal California across the river and deepened the but latest estimates indicate a once shallow pond in that area. Thus, Calforiapopulation of approxi- the least tern has historically mately 780 pairs. Historically, nest- frequented the San Dieguito Lagoon ing occurred in colonies on sandy and is expected to increase its use, beaches and mud or salt flats up and including nesting, as suitable down the coast. Recent development habitats are developed. I ~ ~of coastal lands, including the destruc- tion of many acres of coastal wetlands, has drastically reduced the preferred Light-footed Clapper Rail nesting and resting habitat for this species, forcing it to nest in This species was once a commonE marginal areas. Its optimum nesting resident of California salt marshes. habitat is on sterile sand substrate, Destruction of its marsh habitat has I ~ ~with low or non-existent levels of been the major reason for its decline0 human and predator disturbance, near to a present estimated population low waters containing small fish for of 250 birds. Its preferred habitatE feeding. The nesting season extends consists of salt marsh vegetation from April I to August 15. Resting containing both Salicornia and Spartina areas include dikes, mudflats or salt (cord grass) which is most likely to flats. occur in areas open to regular tidal0 I ~ ~~~~~~~~~~~~~flushing. i In San Dieguito Lagoon the least tern regularly feeds in channels and Clapper rails have not been ponds. A nesting attempt in 1973 r c re nteSnDeut on the dirt parking lot was aborted Lagoon. However, if the lagoon can c due to disturbance by dogs. be kept open to tidal flushing, Large numbers (approximately 100) this species may recolonize within of these birds have since been observ- one or two years. ed resting on this lot in pre- migratory groups. Feeding of young a by adult birds has occurred in the area just west of Interstate 5 before the 1977-78 and 1978-79 high N U ~~~~~~~~~~~~~~~~~~~~~~~~~~~~2-15X "':- ?wildlife habitats ', ',~', Upland Species - mammals san dieguito lagoon enhancement plan * reptiles Oily e1 Del Mar, CailIorll~ � State Coaasal Comantrarity rap16rs *passerine IP �:I IFMt san dieguito lagoon enhancement plan Clly ol Dal Mar. California - State Coastal Conservancy 2-16 H ~~~FISH the high salinities and extreme conditions prevailing in closed At least ten species of fish lagoons, most species require are known to inhabit San Dieguito regular tidal flushing for their Lagoon when the mouth is open. Mullet continued survival in lagoons. have been observed in the main river I ~ ~channel near Interstate 5 and large REPTILES, AMPHIBIANS numbers of topsmelt use the lagoon, possibly for spawning. Mosquitofish Fifteen species were observed have been observed only beneath and during the present study. There east of the Interstate 5 bridge when appears to be lower density and the river was flowing strongly. diversity in the lower lagoon area as opposed to the upper lagoon I ~ ~~~Large schools of juvenile fish area, possibly because of the soil O have been observed throughout the type (muddy in the lower area, lagoon, particularly in shallow looser and drier in the upper area) I ~ ~waters (one to six inches in depth). and vegetation structural diversity0 Calm, shallow waters, such as those (primarily grass and weeds in the found in San Dieguito Lagoon, are lower area, and shrubs, grasses, important areas for development of weeds and sub-trees in the upper E I ~ ~~the young of many fishes, providing area). protection from larger fish predators and reducing energy required by the INVERTEBRATES I ~ ~juvenile fish to maintain their position in the water. The high Eighty-seven species of aquatic 1 productivity of embayments also pro- invertebrates are recorded in a vides a high quality food source for San Dieguito Lagoon. Many of these 0 growing fish, and injured fish may species are characteristic of an use lagoons and bays as recupera- unstable water system tending to tion areas. rely primarily on recruitment from the sea to maintain their popula- Fish use San Dieguito Lagoon tions, rather than on reproduction extensively at present when the lagoon within the lagoon itself. With time I ~ ~~is open and would likely increase and a continually open lagoon their use of this wetland if tidal entrance, species diversity and E action were increased sufficiently density should increase, whereas m to keep the lagoon mouth open most of species dominance should decrease, the year. Although some fishes such leading to a more stable community as killifish and mullet can tolerate composition. U ~~~~~~~~~~~~~~~~~~~~~~2-17 - Aquatic invertebrates form a The Globose dune beetle was formerly very important link in the lagoon food common in low beach foredunes along web. These organisms filter large the Pacific Coast, from central California amounts of living and dead organic to Baja California. Localities of matter from the water, as well as feed occurrence are now scarce and popula- on organic debris in the bottom mud. tion numbers low. As with other Small invertebrates are fed upon by endangered coastal species, habitat larger invertebrates, which are in turn destruction has been the primary consumed by fish and birds. Thus, cause of decline. In San Dieguito the diversity and productivity of the Lagoon it has not been seen but would invertebrate fauna is important in the be expected in the coastal sand dune functioning of the lagoon aquatic habitat. ecosystem. MAMMALS Insects are an important food source for amphibians, reptiles, fishes A total of 21 mammal species and birds. Although their ultimate have been recorded at the San Dieguito Lagoon impact on the lagoon ecosystem is in different investigations. In the unknown, it is potentially high. The present study small mammal trapping San Dieguito Lagoon area may exhibit failed to reveal distinct patterns a considerable number of species due in species distribution, although to its association with upland habitats. two mouse species, Reithrodontomys megalotis and Mus musculus appeared to Two rare insect species are be the primary species utilizing potential inhabitants of San Dieguito Salicornia high marsh vegetation. Lagoon, as discussed below. The Wandering Skipper (Panoquina panoquinoides errans ) is a small butterfly which has been considered for inclusion on the federal Endanger- ed Species List. It inhabits a narrow coastal strip from Santa Barbara to ~ Or San Diego (and probably into Baja Califor- , nia). It is known to feed on salt grass (Distichlis spicata), a common salt marsh ~--, grass, and is therefore a potential inhabitant of San Dieguito Lagoon. / ... .. 2-18 I Enhancement Needs and Constraints fauna, but for the water-associated birds (e.g. the endangered Clapper In spite of its degraded con- rail) and other wildlife that feed on I ~ ~dition, San Dieguito Lagoon still aquatic fauna or use intertidal manages to support an impressive habitat for resting or reproduction. variety of birds, including two endangered species. Among the Lagoon' s animal groups, however, the water-associated birds are especially conspicuous and I ~ ~especially sensitive to human disturb- ance, and for these reasons deserve special consideration in the Lagoon Enhancement Program. o Habitats of particular importance to water associated birds are mud flats and open water. In particular, it is desirable to expand nesting and feeding habitats for the two endangered bird species, the least tern and Belding's Savannah sparrow, and to protect them from human and animal disturbance. Diversity I ~ ~and abundance of mammals, reptiles, and amphibians are relatively low, reflecting the distrubed condition of the lagoon's upland habitat I ~ ~and the relative scarcity of fresh- water marsh and pond habitat in the l~~area.g Diversity and abundance of fish and aquatic invertebrates appear5 to vary with the degree of tidal flushing in the lagoon, increasingE when the lagoon mouth remains open for several months and decreasing I ~ ~when the mouth closes. Improved tidal action in the lagoon would enhance * ~~habitat not only for these aquatic 2 -190 Geology Soils Three features of The soils in the San Dieguito the geology of San Dieguito Lagoon watershed have been classified by are important to consider in the Soil Conservation Service into planning for the Lagoon. six associations. In general, these First is the instability of the deep soil associations have the common alluvium on the valley floor. Given attribute of being easily eroded by its unconsolidated structure and the water. This attribute, coupled with presence of ground water, this potential development actions, poses formation may be susceptible to the threat of excessive sedimentationI liquefaction during a high magni- into the lagoon (witness the Crest tude earthquake; thus it is highly Canyon alluvial fan). If San Dieguito unsuited for major man-made structures. Lagoon is to be protected fromI further sedimentation, unusually The second feature is the high sensitive planning and design of erodibility of Stream Terrace, Bay development in the drainage basin Point and older sedimentary deposits. will be required. These formations, generally exposed on steep slopes, pose a severe actual Suitability for Agriculture and potential sedimentation threatI to the Lagoon. This is particularly The Prime Agricultural Lands Report evident on the bluffs at the mouth (coe 94 oenrsOfc of te laoonwher humn ativiiesof Planning and Research) identifiedI are greatly increasing erosion certain lands within the lagoon plan- rates. Also, the existing and pro- ning area as prime agricultural lands, posed development on these same based on the Soil Conservation Service's erodible formations near El Camino system of rating the agriculturalI Real increases the sedimentation suitability ("farmability") of soils. problem in the lagoon. However, the current investigation tends to contadict the OPR report'sI Finally, the geological for- designation of prime agricultural mations in the lagoon area are of land in the area. great visual significance. Their steep, eroded forms with highly con- The Soil Conservation Service's trasting strata colors, give the system ranks each soil type into lagoon area a unique stamp of one of eight Capability Classes, defined identity, adding significantly to bthseritofhelmainsn San Dieuito Lgoon's aturalagricultural use. Class I soils have "few" resource value. limitations and Class II soils have "moderate" 2-20 limitations. Classes III & IV have "severe" or "very severe" limitations which restrict the choice Storie Index. None of the soils at of plants, require special management San Dieguito Lagoon have index practices or both. Classes V, VI, VII values above 79. and VIII are rated as having such severe limitations that they are generally only used for range, wood- land, wildlife habitat, water supply, or aesthetic purposes. To receive a "1prime" rating a given soil unit a "primerating given sil unitThe natural drainage basin of San needs to meet the criteria for either T h eguitorLage ba sin o San Class I or Class 11. ~~Dieguito Lagoon extends inl and to the Class I or Class II. Cuyamaca Range, to an elevation of over The prime land identified by 5700 feet, and covers an area of 345 OPR includes the overflow parking square miles (see map, page 2-4). The area north of the river which was mean seasonal rainfall in this basin i d areanortif in this rivershigi was varies from a minimum of 10 inches along sterilentifed, b en ts invegetiation. athe coast to 32 inches in the mountains. = alsternlegrounde thebsarr oflve ationd Runoff in the watershed is now largely It also includes the salt flat and marsh area surrounding the Fishhook, controlled by the Lake Hodges and Lake as well as the steep slopes (some over Sutherland dams. a 25% slope) south of San Dieguito Prior to the completion of Lake Drive. The soils in this area are Sutherland in 1954, water in Lake Hodges generally too saline to support crop used to overflow the dam periodically, production, but provide valuable However, water has rarely topped it in habitat for the least tern and Belding's recent years; hence, the effective drainage Savannah Sparrow as well as other g wavannah Sparrow asnwel ason oerd basin is the 43-square-mile watershed down- m water birds and song birds. sra rmLk ogs Furthermore, soils in the lagoonstemfoLaeHds.) study area doils inothe qualif primThree major tributaries drain the c qalifyto asecond pratingsem, watershed below the lake: Gonzales Creek, according to a second rating system,anitrtetsramothsuhrn6 the Storie Indx. This indexan intermittent stream on the southern d gi v te stoilse Inumex.rhic rindex fromborder of the flood plain, east of Inter- give toils based onfoumeri fato: froi state 5; La Zanja Creek, which originates profile (roto pe ntrfactio potenal ) along with Gonzales Creek on the undeveloped Iprofie (root pentrfation sotenial), s lohilly terrace between Carmel Valley and the thexr onditios (surfch asop and i San Dieguito Valley; and Lusardi Creek, other conditions (such as acidity which originates inland near the rapidly de- g m or alkalinity). The. Williamsn veloping community of Rancho Bernardo. Two Act(theState' s arar ting ofsmaller water courses drain into the central d fornessignating oflagoon basin from Crest Canyon on the south ing a soil as prime according to the 2-21 and ~~~~~StvnCreontenth I~~~~~~~~~~~~~~~~~~~~~22 The reduced streamflows to the and allowing marine communities to lagoon and the extensive landfilling re-es tabl is h themsel ves. of lagoon wetlands have greatly reduced the lagoon's water area and Enhancement Needs and Constraints tidal prism over the last 80 years.I The present lagoon channel system Most of the lagoon's ecologic is shallow, with an average water and aesthetic problems, including depth of about two feet, and covers low aquatic faunal diversity,I less than 30 acres. The total sub- reduced habitat diversity, poor water tidal and intertidal area of the quality, and high mosquito populations lagoon is only 38 acres. Due to the can be traced to the lack of water .limited tidal prism and reduced run- flow and circulation (either freshwater off, the entrance to the lagoon or tidal). To enhance the lagoon, is often blocked by a broad sand bar, it is of primary importance to make some .resulting in elimination of tidal changes in the lagoon's hydrology.I .influence. This causes a characteristic pattern of high lagoon At least three alternative salinities in the dry (summer) season hydrologic systems are possible: aI and low salinities in the wet (winter) freshwater or brackish impoundment season. Some portions of the lagoon over the entire length of the lagoon dry up completely during the summer. channels, a partially impounded and partially tidal system, and an open This pattern of changing salinity tidal system, with or without a small and water surface area was stabiliz- freshwater segment. The impoundment ed for a time by the addition of alternatives might be difficult to keepI sewage effluent. Nutrient-rich supplied with fresh water and would effluent, however, presented another have greater maintenance requirements, set of problems, including oxygen flood hazards, and potential forI depletion, sludge build-up, odors and stagnation than the open tidal alterna- insects. The lagoon reverted to the tive. A permanently open tidal system former regime of widely varying would be difficult to achieve, salinity and water surface area when given the small size of the lagoon, the sewage effluent was diverted to However, any substantial improvement the San Diego metropolitan sewer in tidal flushing and water circula- system and an ocean outfall in 1975. tion in the lagoon, achieved by increas-I However, exceptionally high rainfall ing the area of the lagoon available to during the winters of 1978 and 1979 tidal action, would significantly en- has caused the mouth to remain open hance the lagoon.I during mbst of these years, thereby 2-22 improving water quality significantly developrnent and use features Governmental Jurisdictions A number of other agencies hold various levels of interest over Four- governmental entities activities taking place within the have general jurisdiction over the lagoon planning area. Federal lagoon planning area: the Cities agencies include: Army Corps of Engineers, of Del Mar and San Diego, the County U. S. Fish and Wildlife Service, Environ- of San Diego, and the State of mental Protection Agency. State California 22nd District Agricultural agencies are: California Conserva- Association. tion Corps, Department of Fish and I ~ ~~~~~~~~~~~~~Game, State Lands Commission and State The lagoon area west of Inter- Water Resources Control Board. On state 5 is bisected in a north-south the local level agencies with jurisdic- direction by the City boundary between tion include: Regional Water Quality t Del Mar and the City of San Diego. The Control Board and the County Health City limit coincides with the east Department and the Cities 'of Del * ~~edge of Turf Road at the north end Mar and San Diego. E * ~~and bisects Crest Canyon at the south end. The northern strip of the fair- In addition to permit review grounds, approximately 500 feet authority, all of the above agencies0 south o~f Via de la Valle, from Turf have an interest in the management Road to th ocean, les in theof the San Dieguito Lagoon, as do County of San Diego jurisdiction. San Diego County Flood Control, I Nearly ~~~~~~~~~~City of San Diego Engineering Depart- of the river to Via de la Valle, Organization. Coordination among between the railroad and Interstate staff representatives is essential, 5, is under the ownership and juris- though complex. Proposed actions diction of the State of California for these agencies are found in 22nd District Agricultural Associa- Appendix A. * ~~tion. The exceptions are two small parcels east of Turf Road, one at the northern extreme at Via de la Valle and Turf Road, and the other'at the I ~~southern extreme adjacent to the river. I ~~~~~~~~~~ ~.z3~~~~~~~~~a I~~~~~~~~~~~~~~~~~~~~4 X __ ~~~~~~jurisdictionsI ___________ Legend ~~~~~~City of Del MarI __ ~~~~~~~~~~~~~City of San Diego ____________ ____ [1111] ~~County of San Diego3 22nd Dist.. Au.. Assn.. ___~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~- MM_ 2-24~~~m ~~~~~~~~~~~~~~VI.D U ___ __ ~~~~~land uselIaccess ____ ~~~~~~~~~~~~~~~~~~ClExistirM Condltilon) ___ ~~~~Legend Recreational E~Parking - Paved 3 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~ ~~Parking - Unpaved i~~~~~~~__ Commercial I Industrial Residential I ~~~~~~~~~~~~~~~~~Public Works Channels I -~~~~~~~~~~~~~~~~ ~~~ Auto Circulation Ab-d~d AEZZJ Vacant ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[EI san dieguito lagoon enhancement Da City of Dal Mar, California -Stals, CoaBstI Conservancy 2-25 __________ ____land ownership Legend ________________________ ~ 22nd District Agr. Assn.3 __________ EZZI ~~~~City of Del Mar __ ~~~~~~~~~CitY of San Diego _____ ______ W~~~~Mildlife Conservation Board __ ___ ~~~~~~~~~~~~~Public Trust __ ~~~~~~~~~Scripps Clinic & Research [I]Del Mar as LI]Cameron Most aghil Presidio Development Co. Surf & Turf -A. T. & S. F. Rwy. * - ~~-*-. LIZ) Misc. Priv, Owners 2-26 Land Use and Ownership Patterns The San Dieguito Lagoon planning Although much of the upland area area is characterized by several at San Dieguito Lagoon is publicly major developments: The 200 acre owned, the channel and wetland area Del Mar Racetrack and the Southern is largely in private ownership but California Exposition complex on the subject to the public trust in Lagoon's northern shore; five road tidelands and submerged lands. and rail crossings of the lagoonThScipClncadRsrh channels (Camino de] Mar, theThScipClncadRsrh Atchison, Topeka and Santa Fe Rail- Foundation holds an 85% interest in road, Jimmy Durante Boulevard, Grand 23.4 acres of land at the lagoon mouth Avenue, and Interstate 5); an abandoned and is currently exploring the property's I ~ ~airfield and two abandoned sewage development potential. The Wildlife oxidation ponds in the eastern portion Conservation Board is negotiating of the planning area. The planning with the land owners to acquire this area also contains a recreational property. vehicle park and golf driving range Ms ftelgo' ot east of the racetrack complex, various channe and the laooten' northo other commercial uses and some light o h ot channel andte northed porio I ~~manufacturing south of the river and o the sothchnel Mare o8,wnoed bydig west of Jimmy Durante Boulevard, and comrie "Del Macr woes bohnoldings some residential development on the c mrseouthare bofthe north canne.Th d hillsides in the southern portion estrpoutho of the notDhnel. Marh8 of the planning area. ~property is the site of the former Parts of the lagoon have been Del Mar Airport, which was used historically used for farming, but during World War II. Asphalt this activity had to be abandoned in remnants of the landing strip and the late 1930's due to degradation of foundations of buildings subsequent- groundwater quality caused by over- ly used for light manufacturing draft and by the construction of Lake industry are still in evidence. Hodges Dam, which deprived the lowerThreanroftesuh0 I ~ ~valley of most of its aquifer recharge T hannelmaindero the welnsasouited suppl. Th SanDieguto Vlleyeastwith the Fishhook channel areE of Interstate 5 is still used forow e b yCmrnMstgiwh grazing during part of the year, but h olndsb Cameo tostaghi wof 2 cefln no economically viable agricultural i tholdsatouthastr pof18artio of land land exists in the planning area west aning area southaster portins ofth I ~~of the freeway. plann ara.Mshahipan7 23-unit residential development on a Public ownership in the lagoon 40-acre parcel in the extreme planning area is divided among the southeastern corner of the planning State of California and the Cities of area. The State Wildlife Conservation Del Mar and San Diego. By far the Board is negotiating with Moshtaghi largest area is owned by the State regarding possible acquisition of of California 22nd District Agricultural this property. Association, whose holdings comprise the 200-acre racetrack/fairgroundI Private ownership extends over complex and a 50-acre parcel immediate- most of the upland area south of ly to the east. the west and south channels and theI Fishhook. The AT&SF Railway C-o. Development of the recreational holds a right-of-way across the west complex was begun in 1933. The first channel and a vacant triangle of land County Fair opened at the facility just east of the right-of-way. The in October 1936, and thoroughbred area between this triangle and Jimmy horse racing began the following Durante Blvd. is held by various summer. As shown on the land use/ private owners and contains light access map, much of the land in theI manufacturing and commercial uses. complex is currently reserved for A major portion is still vacant parking. but with a commercial developmentI pending. The parcel on the south The City of Del Mar owns a few side of the Jimmy Durante B~lvd./San scattered parcels in the lagoon Dieguito Drive intersection is planning area, including a strip of currently used as race and fair land now occupied by public works parking during the summer, but is facilities south of the west channel otherwise vacant. and east of the railroad, and the 6- acre Del Mar Bluff Preserve near theI The northeast-facing hillsides lagoon mouth. The City of San Diego east of Jimmy Durante Boulevard are owns the 14-acre abandoned oxidation also held by various private owners pond adjacent to the north channel and contain scattered single-family and Interstate 5. The City of Del houses. Mar holds an option to lease this land. The extent of State ownership of theI lagoon tidelands and submerged lands has not yet been determined by the State Lands Commission.I 2-28 Existing Land Use Regulations Within the City limits of Del property. However, the Coastal Mar, the lagoon area between Turf Act requires that permitted uses be Road and San Dieguito Drive is zoned spelled out more specifically in the Floodway (FW) to prevent any uses City's LCP. Within the County's whichwoudrestrict or be damaged jurisdiction, the area is zoned A70-8, whch floduflows. (See pages 5-6and an agricultural zoning with minimum 5-7 for a chart describing zoningloainnthfodpi. 5-7 fr a cart escriing zninglot size of eight acres because of its designations). West of Jimmy Durante Blvd. the FW Zone includes the main river channel and spreads The lagoon viewshed west of out from the west side of the railroad San Dieguito Drive facing the river to cover the low areas west to the valley to the east is zoned Rl-40 ocean. The south side of the river allowing one unit per acre of on both sides of Jimmy Durante Blvd. residential development. The Bluff, is designated North Commercial (NC) Slope and Canyon Overlay seeks to allowing low intensity commercial preserve the scenic sandstone bluffs uses which provide a service to the and canyons and steep slopes which community, "offering a lively open air characterize the area, while at the E * commercial environment with sub- same time protecting the public from stantial open space." unsafe development. A floodplain overlay covers the The City of San Diego has zoned portion of the NC Zone between the commercial/recreation area south Jimmny Durante Blvd. and the rail- of Via de la Valle for commercial road, requiring a Conditional Use b es. The Roadltnd Intrict Permit and review by the City land between Turf Road and Inter- Engineer to assure that develop- state 5 is zoned Al-10 for agricultural ment will not constitute an uses, allowing one dwelling per ten acres. The land south of the floodway create a hazard to life, property,isaozneA-1toSnDguo obstrucion to lood flw, noris also zoned Al-10 to San Dieguito or public health, safety or generalDrv.TeCt'FlowyFW creae a azar to ifeproprtyDrive. The City's Floodway (FW) orwpublic healthfsafety or general Zone coincides with the County's designation of the floodway. The portion of the fairgrounds/ am racetrack complex in Del Mar is The privately owned portion covered by the FR Zone, leaving of the hillsidp south of San Diequito development decisions up to the 22nd Drive is zoned R1-20, while the Crest Agriculture District which owns the Canyon Park acquisition is now zoned for Open Space. 2-29 zoning /IloodlinesI Legend Floodway Fairgrounds / Racetrack 1 7 A~Commercial 3 'A ~ ~ ~ Z Agricultural (A-i-10) Med. Density Resid. (R-1- 10) 111111 Mixed CRM)3 Low Reald. CR-1-20) ZIZ Very Low Dens. Res. (R-1-40) Railroad Open Space Overlay C P~~Floodplain Fringe IFEI san dieguito lagoon enhancement -plan C0tY Of DOI Mat. CalitorNIa - State Coastal Congervancy 2-30 Recreational Access E ~~~The most visible and attractive beach The south bank of the river channel access in the planning area lies at the from Camino del Mar to about 100 yards entrance to the lagoon. The wide sandy east of the Jimmy Durante bridge offers beach is visible from Camino del Mar and pedestrian access for fishing or leisure- I ~limited parking is available along the high- ly walking. The bank is uneven, sometimes way. During the summer the area between unstable, and always littered with trash the highway and the ocean provides a dog and broken bottles. Some of the industrial * ~run and horse exercise area not available firms use the river for dumping trash at other locations in the city. Unfortunate- and waste products, a practice which is ly, the beach at the mouth of the river both unslightly and hazardous to the en- poses some hazards to swimmers. An off- vironment, and may also constitute a I ~shore reef generally perpendicular to the public safety hazard. Grand Avenue is the shore causes a fixed rip current which is only public roadway providing access * ~~dangerous to bathers unfamiliar with the over the Fishhook channel into the main * ~ocean. A small shallow embayment at the lagoon area. The habitat value of that mouth of the river provides protected bath- area precludes its use for most types of t ing area but is inadequately protected by public access, but the resource provides lifeguards and has its own hazards. When exciting educational opportunities that flowing, the river moves sand and erodes do not exist elsewhere. holes, causing unpredictable bottom con- ditions. The relatively warm~water from Enhancement Needs and Constraints the lagoon attracts sting rays as well. Finally, the area is littered with broken Pedestrian accessways on the lagoon bottles and other trash, resulting in periphery are limited in extent and un- m frequent minor injuries, safe and unattractive in certain places. 0 To enhance recreational and educational The cliffs above the north beach, opportunities in the planning area, the though attractive to climbers, are un- existing pedestrian and equestrian access-S stable and hazardous. Numberous caves on ways can be improved, vehicular access to the west face have high potential for col- the main lagoon controlled and hazards and lapse. East of the river mouth, between litter removed from the area. I ~Camino del Mar and the railroad is an area which serves both as an important nesting and feeding area for a variety of water- associated birds and as an accessway for g equestrian use and beach or fairgrounds of 2-31X Vehicle Circulation Two major regional transporta- San Dieguito Drive, which inter- tion arteries provide access to sects Jimmy Durante Blvd. south of the Del Mar: Interstate 5 to the east, river, winds south to Crest Canyon carrying 96,500 vehicles per day, than east to Interstate 5, providing and Camino Del Mar to the west, with the western and southern boundariesI a traffic volume of 10,600 vehicles of the lagoon. It is narrow and per day. The nearest freeway offramp curving, with inadequate visibility is at Via de la Valle, which forms for two-way traffic. However, it the northern boundary of the lagoon serves only 31 homes at this time, andI planning area. no immediate plans are made for its improvement, which could involve Turf Road provides access to adverse environmental impacts to the the fairgrounds from Via de la lagoon's south channel and Fishook area. Valle, with congestion being a problem only during the peak Grand Avenue provides the onlyI periods of the fair and races. access road to the main portion of Recent design and signaling improve- the lagoon east of the Fishhook, via ments at the Via de la Valle/Turf a bridge across the South Channel. In Road intersection were successful in San Diego it becomes a private roadI somewhat reducing congestion during providing access to the old airport the 1979 season. site. The bridge is in disrepair and the roadway has not been maintainedI Jimmy Durante Blvd. connects for several years. the Village Center of Del Mar with the recreational facilities at the Enhancement Needs and Constraints north end of town. The bridge which crosses the San Dieguito The disrepair of the Jimmy river south of the fairgrounds Durante bridge and the hazardous is substandard and slated for driving conditions on San DieguitoI replacement in 1981. A study Drive suggest the desirability of road- has already been initiated on that way improvements in these two areas. project and is being coordinated Road widening and bridge constructionI with this planning effort. can adversely impact the lagoon and would require adequate mitigation. 2-32 Summary of I enhancement needs This chapter's inventory of Fauna. The presence of a variety existing conditions at San Dieguito of wetland-dependent birds at San Lagoon has identified a series of en- Dieguito Lagoon suggests the hancement needs and opportunities desirability of enhancing those I ~ ~which are summarized below. habitats with which they are most closely associated, i.e. open water, Habitat Types. The relatively mudflats and, to a lesser extent, low habitat diversity at San Dieguito intertidal and freshwater marsh. I ~~and the relative scarcity of certain The presence of two endangered bird o ecologically valuable habitat types species and the poor nesting success of such as mudflats, ponds and fresh- at least one of them (the least tern) * ~~water marsh point out the need due to human and animal disturbance to increase the variety of habitats suggests the desirability of some in the lagoon and the area now occupied enhancement measures aimed at pro- by the rarer habitat types. tecting these two species, specific-E I ~ ~~~~~~~~~~~~~ally by providing nesting and feeding Flora. The poor health of the habitat protected from intrusion. existing vegetation, the relatively 0 I ~ ~low diversity of plant species and The relatively low diversity vegetation types, and the high of aquatic invertebrates and fish, a proportion of introduced species especially when the lagoon is closed, a indicate the need to control tramp- indicates that an open lagoon mouthlo ling of vegetation, landfilling, should be maintained and the area water pollution, sedimentation and of aquatic habitat in the lagoon ex- other adverse impacts on laaoon panded. The low diversity and abundance I ~~vegetation; the desirability of of reptiles, amphibians and mammals reintroducing species character- reflects the degraded condition of istic of healthy tidal marshes (e.g. the lagoon's upland habitat and the 0 Spartina) by improving tidal action; relative lack of freshwater habitat 1 ~~and the need to protect the two in the area. This indicates the need to rare plant species still found at expand freshwater marsh and pond N the lagoon. habitat and to enhance upland habitat by increasing the structural diversity of the vegetation and the proportion * ~~~~~~~~~~~~~~of native plants. 23 1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~23 0 GeologyadSis Thin Land Use and Ownership Patterns. stability of the lagoon sediments The fact that virtually all them creates the need to restrict de- sensitive lagoon area requiring enhance- 3 velopment on these sediments. The ment is in private ownership indicates - high erodibility of several rock the need for a public acquisition and soil types in the lagoon water- program. Local development regulations shed, along with the sensitivity of the are adequate for the existing conditions,U lagoon to sedimentation, make but implementation of enhancement work it particularly desirable to control will require certain changes. erosion in the watershed. TheI visual beauty of the geologic forma- Recreational Access. The presence tions at San Dieguito Lagoon can be of trash and safety hazards on the retained by protecting these forma- existing pedestrian and equestrian tions and views of them. trails indicates the need to improve the appearance and safety of access- Hydrology. The existing pro- ways on the lagoon periphery. How- blems of low aquatic faunal diver- ever, care must be taken to limit orI sity, reduced habitat diversity, control access where human and pet poor water quality, periodic flood- intrusion would conflict with the need ing or stagnation, and high mosquito to protect the wildlife. Full utiliza - populations all reflect the tion of the educational potential of lack of water flow and circulation the lagoon would increase the value in the lagoon and indicate the need of the wetlands to the public. to increase the lagoon's waterI supply and improve water circulation Vehicle Circulation. The dis- by increasing tidal exchange. repair of the Jimmy Durante bridge and the hazardous driving conditions on Governmental Jurisdictions. San Dieguito Drive suggest the desirabil- The large number of governmental ity of roadway improvements in these two jurisdiction over the lagoon creates struction can adversely impact theI the need for on-going coordination laonadwould require adequate of planning and implementation of an mitigation measures which will be enhancement program for the lagoon. identified in the environmental review I process. 2-34I I~~~~~~~~~~~~~~~~~~~p U~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.~t I~~~~~~~~~~~~~~~~~Bat * ~~a d0)uolago enhanc rnt pln---, introduction This chapter presents the site improvements and design decisions necessary to create an "enhanced" lagoon. It is the portrayal of the physical features which will increase the environ- mental and recreational values of the San Dieguito Lagoon, and is The following objectives have graphically represented by the helped quide research and decision- lagoon enhancement plan map on making toward the goal of lagoon page 3-11. Numbered areas referred enhancement: to in the discussion (such as "Area IX-B") are referenced on 1. Protect the existing environmental the code map on page 3-10 and on the values of the lagoon; inside back cover. 2. Enhance water circulation and tidal flushing in the lagoon; 3. Improve or create a variety of habitats to increase wildlife diversity and ensure protection of endangered species; 4. Facilitate recreational access, vehicle circulation, educational and scientific activities, and any coastal/water dependent uses which do nnt significantly diminish resource values. 3-2 CREATING A MARINE ENVIRONMENT Two key issues in lagoon restora- these wetland areas, alleviate flood tion work in California are whether and control problems while allowing the how to keep the lagoon mouth open natural transport of sand to adjacent to tidal flushing. Alternatives to beaches, and create the potential for keeping the mouth open include: 1) leav- mariculture, the commercial cultiva- ing the lagoon in its present tion of marine organisms..." condition, in which the mouth is closed much of the year; 2) turning This enhancement plan seeks to the lagoon into a brackish water establish a marine environment in the impoundment by permanently closing lagoon, based on the strong evidence the mouth; or 3) leaving a lower that this will create the most part of the lagoon in its present productive biological state, that condition and making an upper portion water quality will improve, and that into a fresh water or brackish im- mosquito breeding will be reduced. C poundment. The following excerpt To reach these ends it is necessary from the DFG report, Natural Resources that the lagoon mouth remain open. of the San Dieguito and Batiquitos Accomplishing this requires the excava- Lagoons (page 82), supports the tion of enough nonds, flats, and marshy open marine status: areas in the interior to ensure that a large volume of water can be "Regardless of the method moved back and forth by the ocean's used in restoring tidal conditions tidal action. (This volume of water to these lagoons, it can be stated moved by one tide is called the "tidal unequivocally that a stable, tidal prism".) regime in the lagoons will permit the rapid (e.g., within two to The design of this enhancement four years) establishment of large plan, based on a series of tidal numbers of marine fish and shell- basins and channel expansions, is C fish, in addition to providing intended to secure an adequate support for a wide diversity of tidal prism. However the state-of- aquatic birds; and, it would per- the-art in this area of oceano- mit the restoration of salt marsh graphic engineering is not sufficient- lands which play an important role ly advanced to guarantee a permanently C in sustaining the productivity open lagoon mouth. However, it is of lagoon ecosystems and nutrition- believed that, at a minimum, the in- P11v enrich near-shore coastal ereacod water qiirface and nricm 'Si11 waters. Tidal lagoon systems would at least keep the lagoon mouth open also reduce the pollution and insect for longer periods between closings, problems that currently plague thereby making manual openings less difficult, frequent and costlv. - This assumption, plus the clear gain of new and valuable aquatic habitat, is believed to justify the water-related site alterations propos- ed in this chapter. If future monitor- ing of the modified lagoon identifies a continuing deficiency in the tidal prism and circulation, it will be neces- sary to expand the tidal areas or seek other engineering solutions. COMPONENTS OF THE ENHANCEMENT PLAN In addition to the construc- The plan also suggests potential tion of tidal basins and expansion additional uses for future considera- of channels to improve the tidal tion.' The following sections discuss prism and flushing action, this each site improvement and activityI enhancement plan proposes the creation in greater detail. of fresh-water marsh, enhancement of habitat areas for endangered species, The proposed enhancement plan a general clean-up of the lagoon, will create, over a period of years and improvement of existing pedestrian with adequate financing, a vital, trails and viewing points, installa- productive marine environment in the tion of educational signs, and San Dieguito Lagoon. There will beI construction of a permanent entrance a greatly enhanced fish and in- to the ecological reserve. Roadway vertebrate resource and an increased realigflments ~-, imnvnvinrpnft~ whir shorebird and waterfowl population.I would not harm the lagoon are Upland species -~ill also benefit. recommended for safety reasons or for maintenance access to the lagoon. 3-4I design criteria This section illustrates how I . OBJECTIVE: PROTECT THE EXISTING Ithe research and decision-making ENVIRONMENTAL VALUES OF THE LAGOON. process has led to specific proposals for site alterations and improvements. A. Design Guideline: IFrom the technical input and informa- The integrity of existing, tion gained from the physical functioning natural systems inventory (see Chapter Two), it (topography, hydrology, vegeta- 1 has been possible to develop "design tive cover) should be disturbed guidelines" which support, but are as little as possible. more specific than, the objectives. In turn these guidelines have led to Design Actions: Ithe identification of "design actions" 1. Unless other constraints are which are quite specific and implement controlling, locate tidal the statements of intent. basins and channel extensions at the lowest topographic U ~~Research for this program has also contours, to minimize altera- led to the compilation of general tion of terrain. guidelines regarding wetlands management 2. Locate southern tidal basin/! which are presented in Appendix D.mufa(AeXA)wy These principles offer further in- from the freshwater drain- sight into the methodology of lagoon age area/winter marsh AP restoration and enhancement. (Area X-C) and existing Salicornia marsh. C In summary this section provides 3. Locate northern tidal basin the connection from the policy within old levees of to objectives, physical inventory, and abandoned oxidation pond environmental impact assessment to (Area X-C) to minimize I the design decisions regarding site alteration of terrain I ~alterations. The process is outlined and avoid destruction of below. Salicornia marsh. * ~~~~~~~~~~~~~~~~4. Minimize use of the heavier types of equipment in excava- tion work. 0o 0- IL. OBJECTIVE: ENHANCE WATER Design Actions:I CIRCULATION AND TIDAL FLUSH- 1. Connect the northern tidal basin ING IN THE LAGOON to the south river channel near its juncture with the north A. Design Guideline: channel, and connect the Land alterations should ex- northern and southern tidal pand the water surface (with basins with a pipe underneath increasing depth of channels Grand Avenue, to make maximum a secondary function) to use of tidal action to drive water improve the tidal prism and circulation. increase aquatic habitat. 2. Extend the Fishhook channel (Area X) into a loop connect-I Design Actions: ing with the south channel just 1. Create three tidal basins below Grand Avenue. approximately doubling the 3. Install windmill-driven pumps in the water surface area of the new freshwater marsh (Area VIII) lagoon. to provide enough water movement 2. Widen and extend the and aeration to prevent stagnation. Fishhook channel.I 3. Deepen channels, as econo- C. Design Guideline: mically feasible, to reduce Land alterations should be located so friction and drag on tidal as to reduce the risk of their beingI exchanges of water. destroyed by a flood. B. Design Guideline: Design Actions: The land alterations should 1. Connect the northern and south- create a pattern of water circu- ern tidal basins to the south chan- lation and flushing which re- nel and Fishhook, which do not auces mosquito breeding, Lui-1 flood waters.I stagnation and pollutant 2. When economically feasible, buildup. deepen the main river channel to increase its flood-carry- ing capacity. 3-6I ,J jECLiY_: IMPROVE OR CREATE A VARIETY OF HABITATS TO IN- CREASE WILDLIFE DIVERSITY AND ENSURE PROTECTION OF ENDANGER- * ~~~ED SPECIES, AED SPECIE: B. Design Guideline: A~~~~~~~~~~~. Design Guideline: The lagoon's endangered bird The diversity of the spatial pattern of habitat types should from human and animal intrusion, b nraeadeooe species shoul be isolatedbe increased, and ecotones fromhumanand theirhabitat intrusi(transition zones between different andfrom their habitatrshou e habitat types) should be developed. protected from the adverse impacts of site alterations. Design Actions 1. Create additional mudflat, 1. Design Actions: pond and freshwater marsh Establish a fenced nesting areas, each of sufficient K preserve foran aeasten speiestorincrasethlyootin preserve fr aeahistoeril size to be useful to wildlife by this species (Area V) in an area historicallyspecies, to increase the proportions and createhislands speies (of these relatively rare habitat able focreateingands esut- types at the lagoon and so in- crease overall habitat diversity. ing in the tidal ponds 2. Locate new mudflat, pond, salt marsh E (Area IX-C and X-B). and freshwater marsh areas so as to 2. Complete the Fishhook 2lComplete theoFishhook acreate a heterogeneous spatial loopvtoisolize and rea s- pattern of habitat types. 9 3. Create edge cuts and indentations tressed Salicornia, there- along channels, as feasible, to by protecting and expanding enhance the diversity of aquatic the habitat of Belding's habitat. Savannah Sparrow. __ 4. Retain existing vertical structures ac 3. Locate basins to avoid Sali- and add new onesincluding pilings cornia along waterways, in the water and trees on land, to t-o-p-otect the nabitat ofprotet thedg habtann enhance the diversity of habitat for of Belding's Spavanna aquatic invertebrates, fish and birds. 4. Select and operate ex- cavation equipment to minimize impact on exist- ing Salicornia; minimize use of dredgers and drag- line, unless the latter can work from a non- vegetated area. 35 I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- IV. OBJECTIVE: FACILITATE RECREA-I TIONAL ACCESS, EDUCATIONAL AND SCIENTIFIC ACITVITY AND ANY COASTAL-OR-WATER-DEPENDENT USES WHICH DO NOT SIGNIFICANTLY DIMINISH RESOURCE VALUES. A. Design Guideline: Design Actions:I Recreational access for educational 1. Place trees and vegetated viewing should be controlled and berms between human use areas sited to minimize impact on and wildlife habitat, wher- wildlife. ever feasible. Design Actions: 2. Require substantial mitigation 1. Locate lagoon viewing site, for loss of vegetation adjacent fishing sites and trails in to the lagoons.I appropriate areas which are 3. Require structures adjacent already heavily used. to the lagoon to be "sub- 2. Provide fencing or vegetated servient" to the terrainI berms between areas of human in design, coloring and activity and sensitive materials. habitat areas. (For the Least Tern nesting preserve, rely on fencing to protect the Terns and retain the open vistas favored by the species.) B. Design Guideline: Any physical structure, roadway improvement or other development, should be located and designed to protect wetlands, scenic values and wildlife habitat. 3-8I coniponents of the plan improvements of Tidal Areas TIDAL BASINS The "railroad triangle" (Area IV). a 3.5-acre parcel of Construction of three new tidal vacant land, now separated from the basins is proposed in order to increase lagoon's west channel by the railroad ( the lagoon's tidal prism (for improved embankment, would be excavated and I ~ ~flushing) and to increase the aquatic joined to the west channel by a pipe. habitat area. Together with the This will result in about three acresa proposed channel enlargements, tidal of new water surface, increasing the I ~ ~basin construction will expand the lagoon's overall tidal prism by area of the lagoon subject to tidal about ten percent. action from about 40 to 70 acres, increasing the tidal prism by 50 to An added benefit would be the 70 percent. Although there is no improved flushing of the area, guarantee that this increase will be eliminating mosquito breeding sufficient to keep the lagoon problems which occur when stand-E I ~ ~mouth open permanently, it will at ing water builds up in the depressed least keep the mouth open for a longer area. ' period during the year and reduce the0 I ~ ~need to remove the sand bar mechanic- Excavated soils from the project ally. would be used to construct a land- - scaped berm to provide a buffer from The sites proposed for tidal basin adjacent commercial developments. l construction were selected on the basis I of their present low value to wildlife, The northern tidal basin low elevation, proximity to lagoon (Area TX-C). An abandoned 8-acre c channels and, for Area IX, the sewage oxidation pond adjacent to the existence of levees from an abandoned salt marsh at the channel fork would sewage pond. be excavated and connected to the south channel with a new channel. The levees U ~~~~Three tidal basins are proposed surrounding the pond would be reconstruct- C for construction along the lagoon ed and other existing channels cleared channels: out to improve water circulation in I ~~~~~~~~~~~~~~~the area.& I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- I L~~~~~~~~~~~~~~~~~ __-,- r~~i3 pr~o~posed~ pro~ject ( ~~~~~~~~~Sub-Area Reference CodeI B~~1~UD areas when referred to in the For use in locating ground ~~loo~~l"" Sub-A~~~reaswe referred toin th 6'1. text of the plan. rr.~~~~~~~~~~~V1 ii> XIV. l~~~~~~/YvI X~~_ Z_ Vill. IlV. rl Freshwater Marsh IX-c IX-A 8!$ Northern io TeDai Dasln X-B TIdal Sas Ol . IL.. X. Winter Marsh X-C Gr..lvFc Scat. Mot~~~~~. san dieguito lagoon enhancement pan City of Del IMer, Callornra - State Conaotl Comsemvaucy 3-El I ~~~~~~~~proposed profsc Safhernaiao U111ilnvat., Plan I~~~~~~~~6orok- 3 a a 1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~meingsee U~~~~~~~~~WSai rsveo as I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ______ I __~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~P n CIt MkM Dell Marafcnahtt oatlCnsrac I~~~~~~~~~~~~~~~~~~~~~~~~T The southern tidal basin Channel improvements are proposed (Area X). The area adjoining the for the following specific areas: eastern arm of the Fishhook would be excavated and graded to create a South Channel and Fishhook (Area X). 10.1-acre tidal basin and 5.7 The channel should be widened and acres of mudflats. Manual labor deepened and the Fishhook extended would be used to excavate narrow north and west to rejoin the southI channels to increase the marshy channel below Grand Avenue. This will character of the area. create a 20-acre interior island for bird use which would be protected from After completion of both the human and domestic animal intrusion by northern and southern basins, a the encircling channel. pipe will be installed beneath Grand Avenue to provide a connection Interior of Fishhook (Area X-B').I and ensure improved tidal flushing Using manual labor to avoid extensive and water circulation. habitat damage, small channels should be dug criss-crossing the island within CHANNEL IMPROVEMENTS the Fishhook. This would provide high quality salt marsh habitat for aquatic In conjunction with the con- species and ensure that water circula- struction of tidal basins, it is tion is maintained to prevent stagnation, proposed that the major channels odors, and mosquito breeding. of the lagoon be widened and deepened to enlarge the tidal prism, and Marsh at the junction between theI thatminor alterations of smaller north and south thannels (Area IX-B). channels be made to improve water Existing small channels should be circulation. All channel depths cleared and new channels dug, again byI and bank slopes should be specific- manual labor, to improve water circulation ally designed to provide the greatest in the marsh area. value to the biota as well as to improve water circulation. Winter Marsh (Area X-C). The existing low area between the Fishhook and Inter- These improvements would provide state 5 should be channelized to additional habitat for aquatic species, facilitate the inflow of fresh water fromI and also reduce flood hazard in the the hillside and freeway embankment dur- planning area. ing winter storms. This flow creates an intermittent freshwater marsh of value toI migrating waterfowi. 3-12 North and west channel (Area XIII-B). intervals. This will ensure that adequate Deepening of the main river channel. should water quality is maintained in the lagoon be accomplished to increase the flood to support the marine species which will carrying capacity of the river for flood have established themselves in the protection, as well as to improve water channel and marsh habitats. Chapter IV circulation and reduce tidal flow discusses lagoon monitoring and the I ~friction. roles of the Department of Fish and Game and the California Conservation Marsh and pond east of Camino Corps in developing an experimental I ~del Mar (Area II). This low-lying program to ensure an open lagoon mouth. marsh area should be cleaned up and the channels should be enlarged to improve water circulation and prevent stagna- tion. Some deepening of the channels will enhance the habitat value for aquatic species and should also reduce I ~the amount of human and domestic animal intrusion. The work would be planned so as not to prevent or between the racetrack and beach alongE the southern edge of this marsh area. I ~~~See Appendices B and C for details I about the proposed tidal basins and C * ~channel improvements. ( OPEN LAGOON MOUTH SCN I ~With the improvements of water C * ~circulation in the lagoon and the expansion of the tidal prism, it is expected that the lagoon mouth will I ~remain open throughout all or at least most of the year. If experience shows that the expanded tidal prism I ~is still insufficient to maintain tidal flushing, the mouth of the0 lagoon should be mechanically (by hand or bulldozers) opened at regular I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~3-135 Willif Haitat Improvements FRESHWATER MARSH CONSTRUCTION ENDANGERED SPECIES HABITAT Iisproposed that the abandoned The new salt marsh, mudflat 1 aceoidtio podajcett h and open water areas created by the 14-arth chiannel pond adacntertoathe 5(raproposed tidal basin and channel improve- VIII) be converted to a freshwater mnswudpoieadtoa edn marsh and islands suitable for bird habitat for least terns and feeding, nesting. Creation of the marsh resting and nesting habitat for Belding's would return freshwater wetland habitat Savannah Sparrows.3 - ~'//,~, ~i~i~to the planning area. This improve- I sas rpsdta etn aetwll spcesdvrsitlyan increasethovr habitat for Least Terns be enhanced in al prdcte iverity ithlagond anrease three areas described below. The sites I pronutversion ofthe oxiationond area were selected because of their existing masCouldvequresionor teoxcavationpodt relatively high elevations, their proxim- mangradng anud seuirelminor texcaaton d ity to water areas for tern feeding, anwgaing, wandspligtherpon isolation from human and domestic with water. ~~~~~~animal disturbance, and/or history of About 70 acre-feet of water mustnetgoresigu.3 be diverted from the San Dieguito Northern tidal basin (Area IX-B). River at peak spring flow. Water An area of higher ground in the salt losses to evaporation and seepage marsh just west of the proposed tidal3 (up to 40 acre-feet a year) would be basin would be raised further and cover- replaced from groundwater supplies. ed with a layer of light-colored sand, Present analysis indicates that water a surface favored by nesting terns. pumping by two windmills, augment-1 ed by winter rains, should replace Southern tidal basin (Area X-B). the losses. Prior to implementa-InetdigheFsoktomtte tioi c,'~ ths phse, mor thooughsouth channel, a small island of higher analysis of wind patterns and windmill ground would be left within the Fishhook performance is necessary. Adequate channel extension and covered with light- aeration may be achieved by the circu- colored sand. lation caused by pumping, but if not, the windmills should generate enough power to run the necessary equipment to prevent eutrophic conditions. 3-143 UPLAND HABITAT Overflow parking lot (Area VI). All upland areas of the proposed A 12-16-acre parcel between Turf ecological reserve (largely Areas IX Road and the north channel would and X) should be cleared of rubble be protected by fencing and enhanced and weeds and revegetated with native with a covering of light-colored sand. species. In their present disturbed The parcel, currently used as an over- condition these upland areas receive flow parking lot for the racetrack and limited use by wildlife. The recommend- fairgrounds during the summer, is ed improvements would increase the one which the terns have used for nest- habitat value of these areas, thereby ing in the past but with no success increasing the abundance and diversity in the last ten years due to disturb- of wildlife at the lagoon. ance by domestic animals and people. In addition, a sand dune plant preserve would be created in Area I to protect rare or unique native plants from further losses to foot traffic. A representative area would be fenced off, educational signs would be posted, and non-native flora would be removed. This preserve could also provide habitat for E the Globose dune beetle, a rare species known to inhabit dune vegetation. 0 I~mh"- _ - 3-15 _____ L I~~~~~~~~~~~~~~ e9Fr ip Pedoslria~'~ droposed pr aci Overlook Access and Circulation Plan "r i! D ~~~~~~~~~~~~~~~~rail Fishing Points ;~ ~ ~~~~UJp _ I "i ii ~ -Bridge Replacement Sandlot Recreation Grand Ave. Maintenance Entrance r- I C San Dieguito Dr. Narrows Is~~~~~~~~~~~~~~~~~ OvernIght VIsitor Facility , ",,. 4eL-_~_____ I c~s~~~a' to lagoon enhance%9t~~~i~ sa n 0u~ . nenacement pIan3 City of Del Mar, California State Coastal Conservancy 3-16 improvements for Public Access SCENIC IMPROVEMENTS, PUBLIC ACCESS, AND RECREATIONAL/EDUCA- TIONAL OPPORTUNITIES All the site improvements improvement of pedestrian trails on the c described above would substantially periphery of the wetlands; construction improve the scenic quality of San of an informational kiosk at the inter- Dieguito Lagoon by creating greater section of Jimmy Durante Blvd. and San vegetative diversity, more open water Dieguito Drive; installation of education- and less stagnation. To enhance al signs; establishment of a program of scenic values further, the plan public involvement in lagoon restoration proposes a general clean-up of debris and maintenance; and development of a throughout the lagoon to be conducted controlled trail for educational tours of partially by a volunteer citizens effort. the lagoon. Active recreational use Ongoing maintenance will attempt to (volleyball and other sandlot sports) retain the lagoon's unlittered of the least tern nesting preserve in scenic appeal and to remove safety Area VI would be encouraged in the off- hazards from the area. season (September-March) when the terns are not nesting. Proposed improvements in recreation- al access to the San Dieguito Lagoon Access in the buffer areas should be include both control of direct access encouraged and facilitated. The trails c to the resource and provision of recrea- along the water's edge can be improved tional opportunities within the buffer by establishment of an ongoing clean-up areas. Direct access must be restrict- and maintenance program, control of dump- ed because of the impact it would have ing, and erection of appropriate signing. on the ecologically sensitive resource In addition, pedestrian overlook and C area. Educational use and maintenance access areas should be enhanced at activities will be carefully controlled various locations, as follows: to minimize any negative impacts on the ecosystem. 1. Retain a 50-foot pedestrian accessway along the south bank of Several measures are proposed the river channel between Camino to encourage recreational and education- del Mar and the railroad right-of- al uses that do not harm lagoon resources: way. Post a "pedestrian access" sign. 3-17 15 2. Construct a bench for pedestrianI use on the north side of the river channel, east of the high- way, overlooking the lagoon (Area II). Design an informa- tional sign onto the bench back. 3. Police commercial activitiesI along the south bank of the river east of Jimmy Durante Blvd.I to insure that dumping of waste into the river is discontinued. 4. Improve trail along the bankI south of the river and east of Jimmy Durante Blvd. Post signs for pedestrian access. Off-season use of the least tern nesting area for recreation would increase public recreational opportunities in close proximity to existing facilities and would not reduce the value of the area as nesting habitat. In fact off-season activities can provide a maintenance function by discouraging growth of vegetationI which would harbor predators, and by churning up the substrate, making a better surface for tern nesting. VEHICLE CIRCULATION Several roadway improvements near Federal Disaster Relief assistance. the lagoon are being contemplated by However, its condition remains substandard the City to improve traffic flow and and plans are being prepared to replace safety. These improvements are discuss- it with Federal Aid for Urban Bridge ed here in terms of their relationship Replacement funds. to lagoon resources. As improvements E are initiated, the environmental review Short-term impacts resulting from process for each project will identify the construction activities will be adverse impacts and propose full mitigated insofar as is feasible. There mitigation before permits are issued. should not be any additional signifi- cant long-term impacts since the new The following proposed roadway bridge will be essentially a replace- improvements and related impacts are ment for the existing bridge. noted: Grand Avenue. The only vehicle San Dieguito Drive. The current access to the lagoon is via Grand paved surface -nr San Dieguito Drive, Avenue which is presently a dedicated as narrow as 14 feet in some places, roadway from San Dieguito Drive to is already above capacity for the 31 the Del Mar City limits. In San Diego existing homes on the hillside above it becomes a private road providing and in Crest Canyon. A coastal access to the old airport site. The permit issued for a private subdivision bridge across the river channel is in at the east end of San Diequito Drive 1 disrepair and the roadway has not was conditioned upon the develoner's been maintained for a number of funding of road improvements which years. The capacity of that roadway may be required to serve the new should not be expanded. However, development. Widening of the road to E it shiloO He- mintained tn ensure that handle increased traffic should avoid it will be adequate to orovide any filling in the Fishhook channel emergency and maintenance access for area, since such filling would the freshwater marsh and other habitat result in adverse impacts on the lagoon areas. environment and destruction of some- of the wildlife habitat along the Jimmy Durante Bridge. This bridge channel bank. A full EIR will be south of the fairgrounds/racetrack required for approval of any road comolex was originally built in 1036. improvements and the project must It suffered storm damage during the include maximum mitigation of adverse spring of 1979, and was renaired with imnacts. 3-19 Potentia Iadditional ue In addition to the environmental was formerly common in coastal salt enhancement work proposed for the marshes, it is rapidly disappearing from lagoon, there are further developments these localities. Salt flats provide which would meet broader community the habitat required by this species. needs and/or which would not conflict with the primary goal of lagoon After the land is under public enhancement. Several laqoon-related management, the establishment of such uses have been proposed in the past preserves is dependent upon the willing- and, although not now specifically ness of the Department of Fish and Game included in the project design, could to set aside land for this purpose, be developed at a later date (subject the availability of funds and the to full EIR and permit review). contribution of expertise from con- Appropriate uses could include a cerned scientists and citizens. rare plant preserve, aquacultureBILGCLSAE facilities, a biological sewageBILGCLSWE treatment system, and a nature TREATM1ENT SYSTEM1S study center. RARE PLANT PRESERVE ~~~~It may be possible in the future to develop a biological system of wastewater treatment at San Dieguito After completion of the enhance- Lagoon. The biological processing of ment features in the lagoon, it would sewage by marshes may be combined with be desirable to set aside various aquaculture, as described below. Such areas which can be used for trans- joint use can be economically advanta- planting and establishing rare coastal geous. It can also: plants. Transplanting in the main lagoon should not occur until all site 1. provide reclaimed wastewater for uses alterations are completed to ensure (such as lagoon flushing) that would that these plants would not be disturb- otherwise contribute to the demand ed and that their presence would not for new fresh water; conflict with necessary site construc- tion work. 2.provide a low-energy method of waste1 processing; and An example of a plant which could be transplanted into such a preserve 3. expand freshwater marsh areas (prefer- is the salt marsh daisy (Lasthenia ably upriver from lagoons). glabrata coulteri). Although the plant 3-20 There are several problems with AQUACIILTURE such a process. There must be a large area available for a series of ponds Aquaculture is the controlled I ~which receive the progressively cleaner production of organisms in a water water. Possible odors could conflict system, which may be either an impound- with nearby human uses and mosquito ment (usually humanmade) or an open body I ~control in a highly vegetated marsh of water (usually a bay or estuary). is often a problem as well. Objectives of aquaculture are generally either food production or waste treat- the San Diego Regional Water ment. Quality Control Board maintains that past experience does not indicate all Organisms produced in aquaculture problems can be resolved. The systems include fish (catfish, mullet, I ~current policy is to prohibit any sew- etc.) invertebrates (clams, shrimp, age discharges into lagoons. lobsters, oysters, etc.), and plants (water hyacinth, algae, etc.). Culture The State Water Resources Control of some of these organisms has been Board generally favors a more flex- practiced successfully in the Orient ible use of reclaimed sewage to en- and other parts of the world for many hance beneficial uses. In late 1978 years. Catfish, trout and oyster the State Water Resources Control Board culture have been commercially success- A enacted Resolution No. 78-15, which ful in limited locations in the q asked the Regional Board to justify United States, but culture of other I ~ ~its water reclamation policies, especial- species is still experimental. In ly in relation to the presently general the technology is felt to beE degraded status of many groundwater advancing but is not yet to the point basins in the county. To date the where success is assured. ' Regional Board has indicated it is un- willing to change the standards. The use of aquaculture in San Until the issue is resolved, waste- Dieguito Lagoon was suggested by the I ~water reclamation cannot be used to Cal Poly Coastal Design Group (1977), create new freshwater marshes nor to which made the following proposal:S augment lagoon flushing. "At the site of the former oxidation pond a combination aquaculture-wastewater treat-E ment system would be established. The system would receive secondarily treated waste water ... [which] would then be biotically processed0 totertiary quality... [The system] would serve the needs of aquaculture production ... [and] 3-21 ' would allow the City of Del Mar to re- N lATURE STUDY CENTER claim its wastewater for irrigation, for certain types of non-potable human uses, The potential for a nature and most importantly, for a fresh water study center at a non-sensitive site component of the lagoon ... enhancing thenertelgowaidtfednthI lagoo's eosysem wile a thesametimeCal Poly Pomona report, which advocat- producing food... .Revenues [from the system] ed a low-profile, flood-proof, minimal . .mi ght support conti nui ng Ilagoon manage- structure which could be run by ment and restoration. The... .system would university groups doing research on the also give Del Mar the capability to meet lagoon. Aquaculture was again mention- future water quality standards by using ed as a possible function. The economical natural processes rather than ex- center could also be available forI pensive technology... .At the same time, visitors and could be linked to a these practices would serve as a model for controlled trail system. wise and economically sound use of water re- sources." A possible model for a natureI study center at San Dieguito Lagoon Such a use in the lagoon would is found on South San Francisco Say however, reduce the area available for in the City of Palo Alto. The Lucy native marine life and could also com- Evans Baylands Nature Interpretive pete with bird usage. The project Center is a unique public facility must be carefully designed to minimize designed to harmonize with its environ- impact on naturally occurring species. ment. The Center was constructed by the City in 1969 at a cost of $163,000. There are potential sites for aqua- It is built on pilings at the fringe culture and/or biological sewage of a 120 acre salt marsh nature preserve processing facilities on the east side and contains a lecture room, reading of Interstate 5, in an undeveloped and exhibit areas, office, restrooms, portion of San Diego City. That area laboratory and an exposed deck area. is a part of the historical lagoon and An elevated walkway has been built over re-establishment of any wetlands for the surrounding marshland. The Center such uses appears to be desirable. is the focal point for environmentalI education programs conducted for school groups, Scouts, and the general public Development of an aquaculture under the coordination of the City's facility at San Dieguito depends Naturalist Staff. upon leadership by the private sector and/or educational institutions. The potential for such a center will be further reviewed during theI preparation by Del Mar and the Con- servancy of a work program for Phase One of the -implementation plan.1 3-22 a~~~~~~~~ I I I DM * L I I I It, 0 NM * ft~~~~~~~~~~~~~~ I aU 0 I W I I san clieguito lagoon I plan impiementatiorL>--, I introduction This chapter presents High Costs of Wetland RestorationI the means and methodology to implement the site en- As reviewed at page 4-23, the hancement and design decisions costs of wetland restoration areI listed in Chapter Three. extremely high due to the need for Also integral to the implemen- using heavy earth moving equipment, tation plan are Appendix A, Prior work of this kind which is "Recommended Actions for Public applicable to west coast wetlands and Private Agencies", and has been poorly documented, making Appendix B, "Phased Implemen- it difficult to estimate costs tation of Site Construction precisely. In addition, the com-I Work". These are more detailed parative effectiveness and costs of lists of concepts presented the various types of heavy equipment in this chapter. The end have been poorly documented, and theI result of these actions will equipment recommendations made here be the creation of an enhanced may need to be revised as the work lagoon as represented graphic- phase is approached. ally by the lagoon enhance- ment plan map at page 3-11. A major economic and environ- mental constraint on wetland ex- Objectivyes cavation work is the need to dispose properly of excavated soil ("spoils"). As stated in Chapter I, The cost of moving this soil to an the program objectives include acceptable location, when added toI the securing of public owner- the cost of excavation, can be ship or control of the lands prohibitive. Environmental con- in the lagoon; identifying funding straints exercised by Environmental and management mechanisms to Protection Agency and State Water achieve the cost-effective and Resources Control Board over ocean timely completion of site devel- disposal are rigorous and the cost opment work; and conducting of dredge movement of the spoils toI adequate scientific monitoring an approved dumping site is very of the resources and policing high. of human activities to protectI the lagoon from adverse impacts, 4-2 Presently it appears that most 4. minimization of the use of or all of the spoils problem can be suction dredgers (although resolved by making the soil avail- the costs of earth moving are able to the 22nd District Agricul- low once the dredger is on-site, tural Association for its fairgrounds the costs of mobilization and improvements program, now in the of handling fluid spoils are I ~ ~planning stages. This opportunity very high); and has been integrated into the im- plementation plan described in this 5. the phasing of construction work chapter and in Appendices A and B. for maximum efficiencies related to site opportunities and constraints. The methodology and con- Toward A State Wetlands straints of soil excavation are Enhancement Program described further in the con- sultant's report. The final costs of im- I ~ ~Cost Savings plementing this program (as well as others like it) and Various cost-savings have been the degree of success it suggested throughout this chapter, achieves, will depend largely ~~incuigtefloig pnwehrteSaeo California is willing or 1. the use of personnel from the able to initiate a com- California Conservation Corps, prehensive wetlands pre- whose labor is provided to servation and enhancement public agencies at no cost to program. Such an effort the agency; would have to include the acquisition of sufficient 2. solicitation of contributions heavy earth moving andE of some materials from the dredging equipment for 4 private sector; both the. ini tial wui k and the ongoing maintenance that ' 3. deveopment f a stae wet-is required to control in- lands program including ac-filnbysdmtao. quiitonofequipment Until this occurs the highE needed fr wetlan e x cava-costs of commercial contracts tionwetand manenaceva-k for each project will continue tion andmaintenace work;to be an obstacle to wetlands preservati on. Ph as ig I To permit the necessary To introduce the concept, the following flexibility in implementing the summary is provided: enhancement work be carried out Phase One - Minor Channel in a series of phases (which are improvements, habitat keyed to land ownership, type enhancement, and public of resource enhancement need, involvement (lead agency, availability of funds, type of City of Del Mar). equipment to be used and the lead agency). Phased imple- Phase Two - Northern tidal mentation will allow adequate basis construction (lead preparation for each enhance- agency, DFG). ment activity and realization of potential cost savings. Phase Three - Freshwater As each phase is initiated by marsh construction (leadI the lead agency, the costs agency, City of Del Mar). should be recalculated to reflect increases due to in- Phase Four - Southern tidal flation, new information on basin construction (lead the state-of-the-art, and agency, DFG). the analysis in the engi- neering bids received (each Phase Five - Uplands habitat firm will have its own pre- enhan~cement (lead agency, DFG). ferred equipment, methodology, and profit margin). This Phase Six - Flood channelI process will permit "fine- dredin laagnIes tuning" of the plan as it City of Del Mar and U.S. progresses. Soil Conservation Service The pupose ad compnentsor Army Corps of Engineers). of each phase are reviewed in detail in this chapter and in Appendix B. 4-4I agency responsibilities Agency Roles The four agencies which should be primarily responsible for the successful implemen- tation of this project are: the State Coastal Conservancy, the City of Del Mar, the De- mjrrl ihDlMri udn the City of Del Mar, the De-The Conservancy will also have a partment of Fish and Game, (DFG) and the Wildlife Conservation Phases One and Three to a successful Board (WCB). conclusion. Also, in coordination with the Wildlife Conservation Board, the Conservancy will examine and develop multiple funding sources (see Page 4-23) 2 for implementation of Phases Two and gm I STATE COASTAL CONSERVANCY Four by the Department of Fish and Game. Conservancy funding assistance l to the City of Del Mar is immediately E I Conservancy assistance is need- needed to fund the initial program ed to ensure that several phases of the start-up costs ($10,000) and to fund project are implemented in a timely site improvements for Phase One ($59,800), fashion. Especially important is the including $1,800 for the least tern Conservancy's ability to coordinate preserve fence; $11,000 for equipment the activities of the many agencies rental; $17,000 for a culvert to involved to ensure that their planninq, create the tidal marsh at Area IV; funding and permit review activities and $30,000 for earth moving at that are consistent with the lagoon enhance- site. ment plan. Further, the Conservancy can assist the City of Del Mar and DFG in developing a monitoring program E to ascertain the effectiveness of various enhancement activities, such as the establishment of a least tern nesting reserve area. 4-5 estimates and an evaluation of wild-I life and public benefits, including CITY OF DEL MAR the cost effectiveness of the proposal.I In addition to being the co- planner of the enhancement program with the Conservancy, Del Mar DEPARTMENT OF FISH AND GAMEI must ensure that its police Through a cooperative agree- powers (expressed through the ment, DFG would assume primary res- LCP portion of this plan and the ponsibility for management of theI supporting development regula- lagoon ecological reserve after tions) adequately protect the pbi custo scmltd lagoon resources. The City is the p twublicb acustion iscmleted.aec o lead agency for Phases One, Three, I t se TwoFuldbeth land Five nc fo and Six. With DFG (through aPhssToFuranFie cooperative agreement described in this section) it will be OTHER AGENCIESI involved in the ongoing manage- ment of the lagoon. In addition The California Conservation the City will have ownership of at Corps can play a substantial role least 26 acres in the lagoon in completing Phase One. The CCC can area. provide the labor and record-keeping for an ongoing lagoon mouth opening WILDLIFE CONSERVATION BOARD program (to be carried out on anI intermittent or emergency basis as It is recommended that the directed by DFG or Del Mar). Wildlife Conservation Board be responsible for the acquisition Many other agencies also of 216 acres of land necessary have key roles. The U.S. Fish to complete the ecological and Wildlife Service has pro- reserve, as funds become avail- vided valuable technical adviceI able. In coordination with the and will1 have an important role in Conservancy, the WCB should ensure reviewin "Section 404"1 appli- that Phases Two and Four are cationsn~see page 4-li). adequately funded. These recommendations are Teopruiyeit o made wih the rcognitin thatthe Private sector to create a mad womithetb the reogidionfha citizens trust or foundation forI Conservation Board would onlyonogmagentfthlgo. be made at one of its publicAtoaof5acinby1I meetings after a specific pro- Agece toare poposed ation secure ject is presented. The Board'sagnisreposdtoece decision would be based on implementation of this program 4-6 detailed engineering and cost (see AppendixA). Cooperative Agreements To ensure that the implementa- Agreement between the City of Del tion and management program moves ahead, Mar and the California Conservation at least four agreements must be executed. Corps for Phase One. Del Mar, as the lead agency for Phase One, should estab- Cooperative agreement between Del lish a work program with CCC and clarify Mar and the Department of Fish and Game. starting dates and equipment to be This agreement should establish a coopera- supplied. Other phases will require I ~tive maintenance and monitoring arrange- separate agreements. ment for the lagoon. The agreement will be based on understanding that Agreement between the Conservancy when the balance of the lagoon has and Del Mar. The Conservancy should been purchased by the Wildlife Conserva- provide a ~grant to the City to assist tion Board, The Department of Fish and in implementation of Phase One. Joint- Game will recommend that the Fish and ly the staffs should prepare a detailed Game Commission designate the area, in- work program. A contract should estab-0 cluding lands owned by the City of Del lish how the grant money will be used. N Mar, an "ecological reserve" pursuant 1 I ~to the terms of the Fish and Game Code, Cooperative Agreement between the Sections 1580-1584. 22nd District and the Department of Fish and Game. This agreement should be This designation will establish negotiated as soon as possible to enough prpitrineetnth clarify how much spoils material will be laonlands to permit DFG to expend its removed from temporary lagoon storage * ~funds in maintenance and restoration sites for use in the construction * ~activities. The agreement should also activities called for in the Fairgrounds clarify the frequency of visits by Fish Master Plan. The "bargain sale" price E and Game Wardens and the County of the soil should be established at Sheriff, the frequency of trash cleanup, this time, if DFG is enabled to receive and the availability of equipment to be money from such a transaction for use in intermittent emergency lagoon mouth should establish in-kind services that the I ~opening). 22nd District can provide in exchange for the soil. Management of the overflow park- ing lot as a least tern preserve should also be included. I E~~~~~~~~~~~~~~ 1 5~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- f E ww-w ~~~...... prOPOSed acquisitions 'I10li[JI1J0iI]1V 0 ~ -*~ / Legend ~,~:~[~,U ', - . tlUUt]H )||0i||0 . 1[ 't(Scripps Clinic & Research (23.4)* 1W: '.~~ ~ '\% 4 " l L'.I]-Philip JefIferson (3.2)* [ZZ;I -.lDel Mar 88 (1O1.7)* Cameron Mostaghl (87.7) Includes Public Trust Lands 4\ ,T"'. -. ' -- -? G . y f.-\ V--- Total Acres: . 216* san dleguito lagoon enhancement pan City of Del Mar, California � State Coastal Conservancy 4-8 proposed acquisitions ARRANGEMENTS WITH PRIVATE OWNERS A large proportion of the Most of the property is land in the lagoon is currently covered by tidal ponds on the in private ownership. In order main river channel, and probably to conduct enhancement work, it is subject to Public Trust is essential that 220 acres de-. and/or prescriptive rights of scribed below, be placed in the access. Public ownership would ownership or control of a insure protection of the existing I ~ ~resource-oriented public agency. habitat value and facilitate A preliminary estimate places the control of the area for main- cost of this land at about tenance of the tidal flow in I ~ ~$1.5 million. the river. This area would be0 be affected by Phase One of the g It should be noted that the enhancement project. value of any proposed acquisi-_i tions will be established by an "Del Mar 88" (Area IX) appraisal. The citing of this figure does not constitute a This property is held by an I ~ ~commitment to purchase any land investment partnership, The area at this or any other price. totals 101.7 acres, including tidal 01 lands which may be subject to the Scripps Clinic and Research public trust and/or owned by the Foundation (Area 11) state. The majority of the This popertyincluds 23.4property lies south of the main This popertyincluds 23.4river channel and east of the I ~ ~acres on both sides of Camino Fishhook, with a 12-acre portion del Mar west of the railroad. north of the river, The property This area provides visual- and has not been formally appraised, pedestrian access along the but the Wildlife Conservation river to the ocean, and offers Board has expressed interest in vital nesting and feeding habitat its acquisition. Acquisition or for the Belding's Savannah dedication is required for implemen- sparrow and other water associa- tation of Phase Two, construction of ted birds including the Cali- the north tidal basin, and Phase fornia least tern. Five, uplands habitat restoration. I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- Moshtaghi (Area X) Jfesn(raIIA This 2.9-acre parcel lies almost entirely under water in the The enire sothern ortionchannel between Jimmy Durante Blvd. The etire outhrn potionand the railroad. While it isI of the lagoon consists of 87.7 claimed to be privately owned, it areas which may belong to the may be subject to Public Trust and Moshtaghi, a private developer. has no recognized developmentI The San Diego Coast Regional potential. The City should en- Commission has granted Moshtaghi courage dedication of this parcel permission to develop an to simplify dredging and maintenance additional 40 acres south of the of the river channel and to relieve lagoon on the condition that the the owner of maintenance and lagoon property be sold to thelibitprles state at the appraised fairlibitprlesU market value or placed in a permanent open space easement. ARRAINGEMENTS WT ULCONR The Wildlife Conservation Board WT ULCONR is negotiating with Moshtaghi to acquire the lagoon land. Public 22nd District Agricultural acquisition of this property is Association (Area VI) essential for the implementation of Phase Four, construction of The 16-acre overflow parking the south tidal basin. lot for the racetrack/fairgrounds complex is proposed to be part of a Railroad Triangle (Area IV) land exchange after the "Del Mar 88" property is in public management. This 3.5-acre parcel of Twelve acres north of the river railroad right-of-way lies east channel would be offered for parking of the main railroad line and to replace the land to be used as a south of the west channel of the least tern preserve. river. Its south edge isI bordered by the dike that once City of San Diego (Area VIII) supported a second spur which provided turnaround capabilities This 14-acre area was previouslyI for the railroad. Dedication, used by the City of Del Mar as a lease or sale of the property by sewage oxidation pond. It is owned AT&SF Railway Co. to the City of by the City of San Diego, with the Del Mar or the Department of City of Del Mar having an optionI Fish and Game must be accom- to lease which is renewed annually. plished in order to implement the Del Mar will exercise its option as construction of the tidal basin Phase Three nears implementation.I 4-10 proposed in Phase One of this nrogram. permits and approvals To carry out this program, Del Mar will also request a it will be necessary to secure "Section 10" permit (for work local, state and federal permits affecting a navigable waterway) for the proposed enhancement from the Army Corps of Engineers if work. Local permits will come the railroad triangle basin has I ~ ~from theCity of Del Mar and the been acquired for conversion into a City of San Diego. The process tidal salt marsh. The permit is for securing state and federal needed for installation of the pipe * ~~permits for each implementation which will connect the basin to the phase is described below. river. Phase One (minor channel modifi- Before any work is initiated,E I ~ ~cation for water circulation). Del Mar will submit to the Region- Del Mar as lead agency will al Clearinghouse a "negative'declara- . submit an application to the tion" in accordance with the U.S. Army Corps of Enqineers to California Environmental Quality Act, secure the Section 10/404. stating that the Phase One land (for alterations of a waterway modification work will not have a or wetland) as required by the significant adverse impact on the Clean Water Act. This permit environment. will allow the California Con- servation Corps to clear sediment Phase Two (construction of northern I ~ ~and debris from small channels tidal basin and a channel connecting in Areas II, IX-A and X. Del Mar it to the river channel). TheE will also request a "Streambed Department of Fish and Game as lead I ~ ~Alteration Agreement" from DFG agency will be responsible for for the same work, pursuant to securing Sections 10 and 404 permits Sections 1601-1603 of the Fish from the Army Corps of Engineers. and Game Code. The Department will circulate a I ~ ~~~~~~~~~~~~~"focused environmental impact report" The State Lands Commission (based on this plan and limited toE will be asked to determine if significant impacts only) prior to I ~ ~work in the waterways can be the authorization of any actions. considered to be for maintenanceE only, thereby not requiring Commission approval. I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4-11 Phase Three (construction of a fresh Phase Four (construction of the southern water marsh). Del Mar, as the lead tidal basin). The process of obtaining agency (with the Conservancy's assist- permits for this phase is the same as for ance) will complete the design work for Phase Two, with DFG again acting as the the windmill-driven water pumping system lead agency. and prepare a "focused EIR" addressing____I such issues as groundwater supply water Phase Five (improvement of upland habitat). aeration control, mosquito management This phase, involving revegetation of dis- and nutrient residue .in the abandoned turbed areas by DFG, requires no permitI sewage pond. Del Mae will determine or CEQA review. if the State Water Resources Control Board requires any conditions on the ex- traction of 70 acre-feet of water from the river during a period of high runoff. FEDERAL GOVERNMENTI CHART OF AGENCY PERMITS AGENCY AUTHORITY IDESCRIPTION AND REME7WS REQUIRED. U. S. Army Section 404, Strongest wetlands preservation law. Reviews placement ofI Corps of Clean Water fill in wetlands and disposal of dredge spoils. Engineers Act (COE) COE Section 10, Controls obstructions in navigable waterways. Administra- River & Harbors tive process is integrated with the 404 permits. Act of 1899 U.S. Fish Fish & Wild- Comments on COE Section 10 and 404 permits for impact onI & Wildlfe lifeCoordi-wildlife. Can influence allocation of federal funds for Servicdie naion Act;di projects affecting endangered species. (FWS) Endangered Spe,.es Act Environmen- Section 402, Permit for water quality control ("National Pollution Dis- tal Protec- Clean Water charge Elimination System"). Administered by RWQCB; re- tion Agency Act viewed by EPA and SWRCB.I ALL National En- Impact assessment must be conducted by federal agencies vironmental before projects are begun.I Policy Act~~~~~~~ 4-12 Phase Six (flood channel dredging). The City of Del Mar will be the lead agency but the project will require the funding and planning support of the U.S. Soil Conser- vation Service or the Army Corps of Engineers. With a cooperative project, the Section 404 permits for dredging would be expedited, provided the issue of spoils disposal can be resolved. STATE OF CALIFORNIA* AGENCY AUTHORITY DESCRIPTION Regional Section 402, Review to ensure waterways excavation does not cause un- Water Quality Clean Water necessary and avoidable pollution. SWRCB, EPA and FWS Control Board Act have strong review roles. (RWQCB) Dept. of Section 1601- Streambed Alteration Agreement. Review to protect eco- Fish & Game 1603, Fish & logical values; involves mitigation agreement, (DFG) Game Code DFG Section 5653, Controls suction dredging. Fish & Game Code State Lands Articles for Determine state-owned tideland; finding of consistency for Commission Admission of "Doctrine of Public Trust" which provides an easement over California to waterways to MHHW and wetlands. Any use of state-owned the Union, 1850 lands requires lease or permit. State Coastal Coastal Act Reviews Program for consistency. Finding of consistency Commission of 1976 for Conservancy project. Certifies LCP for Del Mar. San Diego Coast Coastal Act Reviews permit application for Coastal Act and LCP consis- Regional Com- of 1976 tency for all development activities including restoration. mission Certifies LCP for Del Mar. LOCAL GOVERNMENT* AGENCY AUTHORITY DESCRIPTION San Diego Review and comment on vector control. Can enter land at County Health will to control nuisances. Department City of Development Local police power is the base of land use regulation. Del Mar regulations All development activities in the floodway require a Conditional Use Permit. *All state and local agencies must also conform to the requirements of the California Environmental Quality Act (CEQA). imnprovernents To initiate this project as 4. The various elements of the soon as possible, it is proposed enhancement work differ in their that it be implemented in six environmental documentation re- phases which have been defined to quirements under the California reflect the following considera- Environmental Quality Act. In tions: general, the implementationI phases are designed so that those 1.Different funding sources will activities requiring the least have to be applied to different documentation are phased earlierI elements of the enhancement than those requiring more work. Elements for which elaborate documentation. funding is readily available 5. Because of the number of proposedI are proposed for early imple- enhancement actions and the mentati on. variety of constraints on imple- 2. Much of the proposed enhance- menting all of these actions, ment work cannot be under- it is quite possible that some taken until the land is under actions will not occur in the public ownership or control. order planned, To allow flex- Work that does not require ibility in implementing theI land ownership transfers is enhancement plan, each phase is included in the first phase of designed to be relatively implementation. Each later independent of the other phases.I phase is designed so that it can be carried out as soon as The phasing approach is especi- the land becomes available. ally desirable because of the un- 3. The various elements of the tested nature of some components of proposed enhancement work this project. Careful evaluation of differ in their equipment the benefits and consequences of requirements. Elements re- each phase should occur before the3 quiring little or no construc- next phase is begun. Occasionally tion equipment are proposed for there may be need for modifications early implementation; later and fine-tuning, due to improvements phases require successively in the state-of-the-art or new infor- heavier equipment and are mation on marsh enhancement. designed so that equipment -14 ~~~~~~usage can be coordinated. The following discussion 2. The City of Del Mar, in coopera- outlines the various elements of tion with community volunteers each phase. (See Appendix B, and work crews from the California "Phased Implementation of Site Conservation Corps (CCC), would Construction Work" for complete conduct the spring clean-up and details.) construct the lagoon entrance, kiosk, and viewing site. Dona- Phase One tions of construction materials I ~ ~~~~~~~~~~~~or funds-would be sought through Phase One includes those the public involvement program. actions which can be undertaken I ~ ~on land already publicly owned or 3. Upon obtaining control of the in the public trust, or for which racetrack's overflow parking area, minimal acquisition or lease the City of Del Mar and DFG would funding would be needed, and for establish the area as a least tern which physical work can be done peev Ae I.Tetase largely by manual labor without should be accomplished, and an al- the need for heavy equipment. ternative parking site located, I ~ ~Elements in this phase would serve pursuant to the 22nd District to build the project's local vis- Agricultural Association Master Plan2 ibility and to develop momentum for now being prepared for the District the completion of implementation by a consultant to the Office of ~~~~cios ithotepae. the State Architect. The area Elements include:ohrphss would be established as a least tern preserve by erecting protectingE I ~ ~1. The City of Del Mar would fencing and by depositing sand to conduct a public involvement encourage nesting by least terns. program which would encourage Sand is available from the Crest I ~ ~~continued citizen involvement Canyon alluvial fan, which was in the enhancement process. deposited as a result of heavyE Among the tasks to be included rains over the past two winters. are the design of the lagoon Labor would be provided by the entrance and kiosk (Area V), CCC. lagoon viewing site (Area II), and information signs for the 4. Following State Lands Commission ~~~~~aonrsre h oic-fnigofpbctrsth tation of donations of materials City of Del Mar using CCC work and services for other actions crews, would undertake the minor I ~ ~~under Phase I; and the organi- channel and water circulation zation of a Spring 10.8O clean- im,.provements at three sites: up of litter, waterway snags, and safety hazards. 41 propsed pro!QI- NOW M~rW~~f1II~ll~D~ll~ Scheamatic Phase On. P'ian BID ~~~~~~~2. Public Involvem*n't 3. Controlled Ac~e*" Railroad Triangle: 11alt Ntaroh/Tidl8"It Se New Marelh Cnannela dirand Ave. Satt Security winter marshI A~~~ Requires land "qu~~~~ ~ ~ ~ ~ ~ID0"O ticTU dtrns0 san~~~~~~~~~~~~~~~ d Dian aft~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ at0 400 fase CtmtrOO aale 4-1 6 ~ ~ ~ ~ ~ ~ ~ ~~ ~~~~~~ the marsh and pond area just Phase Three east of the Camino del Mar ~~~~~bid e (ra1)thmrs This phase involves the con- at the channel fork (Area version of the sewage oxidation IX-B), and the winter marsh pond presently owned by the City of area (Area X-C). San Diego to a freshwater marsh and the creation of two additional bird 5. Following the negotiation of nesting islands (Area Vill). Action a lease or acquisition of the would depend upon the negotiation of AT&SF Railway Co. property a low-cost lease for the site, The (Area IV), the City of Del Mar City of Del Mar currently holds an and work crews from the CCC option to lease the pond. I ~ ~~~and DFG would restore the Wr ak nld earo area as a tidal basin. Site Wr ak nld earo work would include excavation levees, clearing of vegetation and I ~ ~~~and installation of a pipe sludge deposits from the bottom of connecting the new marsh to the pond, creation of two bird nesting the west channel. islands, filling of the marsh with 70 acre-feet of water from the San 6. The City of Del Mar will Dieguito River during the high winter establishcontrolld accessrunoff period, and erection of two trails, lagoon viewing sites, wnmlsto pupi replac waterlosbevprtn I ~ ~~and educational signs at t elc ae osb vprto appropriate locations (see map, and seepage.5 * ~~~~page 3-16). Phase Four Phase Two The actions in Phase Four may Phase wo incudes te con-take place once the Moshtaghi I ~ ~struction of the northern tidalpretyiunrpblcoesh. basin and nesting island (Areas The Wildlife Conservation Board is IX-A and D), which would be possi- currently pursuing acquisition of I ~ ~~ble upon public ownership of the this property. The activities 101.7-acre Del Mar 88 property. proposed under this phase mightU This phase would require some heavy involve the use of a dredger. equipment such as trucks, a swamp Ti hs nldstedvlp cat and possibly a dragline. Ti hs nldstedvlp Tasks would include the recon- mudflats, the creation of a least struction of levees and excavation tern nesting island, the deepening of a channel connecting the tidal and widening of the south channel basin with the south channel, and south of Grand Avenue, and the g creaton an enhacemen of aleastwidening and extension of the Fish- 41 tern nesting island. h o k c a n l ( rsXAadC) proposed pi:Qec 0 ~~~~Schematic Phase Two & Three Plan no~~~~~~~~~~~~l North Tidal Basin Development 'Ill. Fre~hwater Marsh Developmenlt improved Marsh Water Circulation Cu1) Freshwater Marsh (Ill)I CHV~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 400 00 M. C0rn0-0Ua o 4-18 ~~~~~I L4 I~~~~~~~~~.T Epjposed project Schematic Phase Four Plan South Tidafl Basin Development ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~nIsln . ~~~~:: P~~roshwator Inflow sn do ulto lagoon enhancement_ 4-19Q Phase Five Phase Five involves the cleanup and removal of debris from upland areas (primarily Areas IX and X) and revegetation with native species, and also the establishment of a small preserve for rare dune plants (Area I).I These activities would be carried out by DFG pursuant to its regular management duties once the land isI under public ownership. Phase Six Included in Phase VI is the dredging of the main channel of the San Dieguito River and theI northern portion of the south channel (to the Grand Avenue bridge) to reduce flood hazardsI and to enhance the lagoon's tidal flushing capability. 4-20 monitorin, gniteac and policing Because of the interrelated Monitoring in the San Dieguito. concerns of many agencies and the Lagoon would assess the effects of public, it is recommended that a enhancement procedures on physical task force be established; meeting and biotic conditions in the lagoon. monthly to coordinate various It would also determine the critical implementation and management activi- time for opening the lagoon entrance ties needed to enhance the lagoon. It (during periods of closure) to permit is proposed that this task force be continued existence of the fauna and I ~ ~made up of representatives of the flora, and it would identify those Cities of San Diego and Del Mar, San rare occasions when the tide may be Dieguito Lagoon citizens advisory so high that it threatens the in- I ~ ~committee, Conservancy, Department of tenior of the lagoon and its wildlife. Fish and Game, Coastal Cormmission, . U.S. Fish and Wildlife Service, and The monitoring program would I ~ ~California Conservation Corps. include the sampling of physical environmental information and the sampling of biological populations. Monitoring Initially, physical data (e.g. on water chemistry) should be collected Closely related to the simultaneously with biological data 4 phasing of lagoon enhancement work and correlations between the two is the conduct of ongoing monitor- attempted. An eventual goal might ing f te laoons biological be the prediction of faunal and and hydrological condition. floral conditions from water chemistry0 Monitoring is especially important data, which would avoid the need for I ~ ~because of the need to determine and expense of regular biological if each phase of the enhancement sampling.U work has been successful enough to ~~prit h etse ob ae.Apoiaetlrnelvl o physical factors in different groups A monitoring program for the of animals are known and can serve as San Dieguito Lagoon could follow a starting point for further lagoon the example of that proposed in the faunal studies. The following physical Conservancy's Arcata Marsh Plan data should be regularly recorded: (1979), with some modifications, B.O.D. (biological or biochemical as discussed below. oxygen demand),D.O. (dissolved oxygen), 4-21 pH, suspended solids, nitrogen 5. Fence lock checks and repair of Nitrate, ammona), phosphorusvandalized areas; (ntrateammni) phosphae rhporspht) 6. Island maintenance; (toaliiy phospavymtal, horthphspate)d 7. Checks of monitoring devices; hyroarbonst, precipitation, whoinatd 8. Mosquito control; hydrocarons, prcipitaton, win Pump maintenance at the oxidation speed, temperature, water circula- pond;U tion, and sedimentation rates and 10. Revegetation: maintain nursery deposits. areas, transplant at appropriate Biological data which should times;3 be colectd siultaeousy inlude 11.Vegetation control: remove emer- becounetsed simuheltanoul indclude: gent plants (cattails) as necess- organisms (eg., E. coli) benthic 12 atrylvlmnplto in freshwae-arh n invertebrates, fish and birds, and 1 .Water lvlmnpultond in conrel squh-s measurements of algal growth and the w atrpnd tocotrolphqiction. growth of macrophytes in newly a n urpicai created or newly planted areas. Policing In general, numbers of species Policing against trespass andI and individuals (or biomass) in the domestic animal intrusion will be lagoon should be determined or necessary to protect the habitat and estimated for each group. Productiv- natural values of the lagoon. The ity estimates for each would also be frequency of policing activities willI useful. The exact information co- depend on the actual usage of proposed llected and methods for these studies accessways in the area. should be reviewed by professionalI biologists, prior to the commence- Private Sector Assistance ment of a monitoring program. Maintenance ~~~~As mentioned above, a citizens ' 5 Maintenance ~~~~~trust or foundation could provide much A varety f mantenace dtiesassistance in monitoring and maintaining by theriety of Delintenandte Depat-e the lagoon, which would reduce public mytenCty of DelsMa and Game maDepareq ird costs. This potential will be examined ThetofFshadGmmybe incuired: by Del Mar and the Conservancy during These include: ~~~~Phase One. 1. Opening of lagoon mouth on an intermittent or emergency basis; 2. Closing of lagoon mouth when high tides threaten interior; 3. Culvert inspection to avoid clogging; 4-2 4. Debris removal from ponds and3 channels; costs and funding The cost of wetland restora- 1. Use of bulldozer, swampcat, drag- tion programs is high (e.g. Arcata line and skiploader: $2.00 a freshwater marsh, 60 acres - $230,000; cubic yard for movement of the San Elijo Lagoon East Basin, 200 acres - soil to a nearby deposit pile $800,000). The San Dieguito Lagoon with later pick up and loading project, in all of its components into a truck (for a direct load including land acquisition, could into truck, due to delays, add require the expenditure of several 50t a cubic yard). This estimate million dollars. However, with the does not include cost of road phasing concept and with the achieve- construction for truck access. ment of proposed economy measures (see page 4-3), the cost can be sub- 2. Use of a suction dredge: $1.00 stantially reduced. a cubic yard, which includes piping the fluid spoils one-half Cost estimation has been especial- mile. This estimate does not ly difficult due to the absence of reflect the mobilization cost adequate documentation on the compara- (for a 16" dredge, $80,000 tive benefits and constraints of the to $100,000; for a 12" dredge, different types of heavy earth-moving $25,000 to $30,000) or the cost equipment. While State and Federal of building a levee to hold the agencies have worked with wetland- fluidized soil while it dries mobile equipment, there are no analyses (which can be 2 to 3 years). of lessons learned and no recommenda- tions on cost-saving techniques or These assumptions are the basis equipment to be used for special purposes. of the cost analysis which follows. Even commercial cost estimates for the simplest bulldozer work are highly Costs variable (different estimates for moving a cubic yard in Area IV were The implementation of the enhance- $1.75, $3,00, and $5.00). Therefore, for ment plan is expected to cost approxi- planning purposes, the following base mately $2.3 million. Acquisition costs figures were used to approximate (based on apreliminary planning estimate) the cost of each portion of the project: are expected to be about $1.5 million for 220 acres of land. Public trust interests which must be determined by the State Lands Commission may exist over a portion of these properties. 4-23 Site improvement costs for all The first four items are contingentI elements of the enhancement plan could upon placement of the respective parcels total within the range of $750,000 to under public management for the stated $900,000 if let to private contractors. purposes. The site work in this phase Cost-saving measures, including the use may also be funded by the California of state-owned heavy equipment and Environmental Protection Program. crews, are possible and have been identified above. Phase Two. About $200,000 for the northern tidal basin construction The estimated costs of each phase, (Area IX-C). The DFG should submit a and the most appropriate funding sources, request for funding to the State WildlifeI are summarized below. A detailed Conservation Board and to the U. S. discussion of the funding sources follows. 'Heritage Conservation and Recreation Service (for funds from the Land and Phase One. Approximately $70,000 Water Conservation Fund). for administration and construction of various site improvements, to be funded Phase Three. $17,200 for the by a grant from the State Coastal placement of windmills in the fresh- Conservancy to the City of Del Mar, water marsh and,.$5,000 for excavation plus substantial in-kind services, (unless excavation equipment is contribut- especially from the California Conserva- ed or borrowed from concurrent work at E tion corps (in the form of contributed other sites). The California Environ- labor). The cost breakdown is as follows: mental Protection Program is a likely funding source for this phase. 1, Least tern preserve (Area VI fence: $1,800; Phase Four. From $270,000 to $425,000 (depending on equipment used) for 2. Preserve equipment rental: $11,000; construction of the southern tidal I basin and new channel configurations 3. Excavation of eastern tidal basin (Area X). Funding should be sought from (Area IV): $30,000; the same sources as in Phase Two.I 4, Placement of tidal pipe: $17,000; Phase Five. An undetermined amount for upland habitat enhancement and 5. Administration: $10,000 establishment of a sand dunes plant preserve. Costs should be covered by DFG administrative funds. 4-24 I ~~~Phase Six. About $250,000 for Department of Fish and Game personnel. flood contro-ldredging of the main river Until the cooperative agreement is channel and part of the South channel to executed and new duties established, I ~be sought by the City of Del Mar from one to two work days per month will be the U.S. Soil Conservation Service as needed for monitoring and coordination I ~a flood control portion (requiring no activities (including the monthly local share) of PL566 "Small Watershed meeting). A Fish and Game Warden should Project" or from the Army Corps of make daily visits, unless other Engineers for a small flood control arrangements are made with the City. I ~project. In addition, DFG should be responsible for the scientific monitoring and water Staffi ng Commiitments sampling program which requires at least monthly execution. (Again, an I ~ ~~It is estimated that the following arrangement with Sea Grant could enable commitments of public agency staff a University scientist to do this work time (totaling two person-years annually) on contract with the City or DFG.) * ~are necessary for implementation of this a program: g State Coastal Conservancy staff Del Mar Lagoon Coordinator. One-half time, Atter execution of the Phase One I ~time will be required for a member of contract and work program, one to two the City's Planning and Community work weeks per month will be needed Development Staff. (An alternative would to monitor progress through Phase One be an arrangement with Sea Grant funding and preparation for Phase Two (in- to place a University scientist on cluding a monthly meeting of all con- A contract with the City.) cerned agencies). The Conservancy should continue its supporting and co- Law Enforcement. At least until ordinating role as long as its funds DFG assumes the major management role, are being used in site improvements. the City of Del Mar should ensure that In the early phases, it should also its contract with the County Sheriff's assist interested persons in establish- Department establishes a daily check ing a citizens trust or foundation to of the Grand Avenue bridge gate and an participate in lagoon management (see in-car visual inspection of the lagoon. page 4-5). The Fire Station near Jimmy Durante bridge could assist in visual monitoring. E I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~4-25 A I~~~~~~~~~~~~~~~~~~~~~~L California Conservation Corps position of all State agencies to labor. In addition to the substantial secure areas for preservation and wo~rk to be conducted by the CCC during enhancement. Lands acquired by WCB Phase One, and possibly in later phases would be managed by the Department as well, the project coordinator for of Fish and Game after the area is the Escondido camp should attend the established as an "Ecological Reserve" monthly meetings, especially if the CCCI assumes an on-going role in emergency Some constraints exist on WCB lagoon mouth opening. regarding site development work. For the most part its funds can be used Fundin to complete structural facilities that directly benefit wildlife or The primary sources for funds to recreational uses involving wildlife, implement the acquisition and enhance- but there are constraints on using ment for this project are: these funds for land movement and dredging activities. Funds for en- State of California Coastal 'hancement can only be spent on lands Consrvan~X. e caue th Conervacy'sowned by the State or, if owned by a bu~dget -is Tor the most part from a loaublcaecudrtecvr one-time bond act share, its capability age of a cooperative agreement to purchase land is limited. More - -between the DFG and the local juris- over, the Conservancy can only fund 40% diction. of any acquisition for an enhancement project. The Conservancy has flexibil- California Environmental Protection ity to fund site improvements but not Program. This program is administered to support on-going management and mainten- by the Secretary for Resources. The ance. he Coservacy shuld povidesource of Program funds is the sale a grant of $70,000 to the City of Del o esnlzdlcnepae n Mar to implement Phase One of this the funds are therefore annually re- project. With the Wildlife Conserva- plenished. They are chiefly used to tion Board, the Conservancy would implement small environmental protection develop funding for implementation of projects that have high visibility Phases Two and Four of this project. and can be quickly implemented. State of California Wildlife Con- Funding for the least ternI servation Board. Land acquisition of reserve (Area VI) and construction of all major parcels should be accomplish- the western tidal basin (Area IV), ed by this agency. With its annual both of which are in Phase One, has funds from the State's share of the been applied for by the Conservancy, racetrack revenues, it is in the best as has the cost of the windmills in 4-26 PaeTre I ~~Land and Water Conservation Fund. U. S. Environmental Protection This fund is administered by the U. S. Agency/State Water Resources Control Recreation and Heritage Conservation Board. The well-being of the San IService and the State Department of Dieguito River watershed is of great Parks and Recreation. It is primarily importance to the long range enhance- used for the acquisition and develop- ment of the lagoon. Environmental Iment of recreational areas. This fund Protection Agency and State Water Re- could be a source for the construction sources Control Board could apply of a nature study center at a future time. Section 208 planning funds from the Clean Water Act to prepare erosion I ~ ~In such an effort, the 50% and sedimentation control strategies. matching funds would be supplied by the ICity of Del Mar. The availability of In-kind services. Also of major this source for any enhancement importance to implementing the lagoon work (other than such small components plan is the availability of in-kind as the native plant preserves, which or contributed services from concerned E have an educational/viewing value) agencies and the public. Phase One is unlikely. of the program largely relies on this0 level of activity, especially with labor Small Watershed Act (PL566). This supplied by the California Conserva- program is administered by the Soil tion Corps. I Conservation Service and is for planning, acquisition, and development for better I ~management of watersheds under 250,000 acres in size. Dredging of the flood channel and related activities could qualify for 100% funding from this ~~suc.Telatimforeiws substantial, i.e., three to four years.E Small Flood Control Project Funds. The Corp-s of Engineers can undertake UL small flood control projects (costing the Corps less than $2 million) without Such projects must be complete in them- selves, resolve the problem, and not require further Federal expenditures. A 50% sharing of costs is generally re- quired. The lead time is one to three years. 42 I~~~~~~~~~~~~~~~~~~~~~~C Mc san dieguito lagoonU land useieguiolagoons--- This chapter presents the land use the ecological reserve from the regulations (zoning, grading and erosion impacts of activities taking place control ordinances and design review in adjacent areas. These controls criteria) which the City of Del Mar should focus on water quality and sedimenta- is proposing to apply to developments tion problems which may result from in and adjacent to the lagoon. Fur- development activities, and the visualI ther refinement of these regulations impact of structures and landscaping is currently being undertaken by the in the lagoon viewshed. Land Conserva- City. This discussion is included tion and Design Review ordinances for in the program for informational the City of Del Mar address these impacts purposes only. The City will independent- and this plan reiterates the established ly submit the proposed regulations criteria, relating them specifical- to the Coastal Commission as part of ly to lagoon impacts and extending the City's Local Coastal Program. them to the portion of the buffer area currently under the jurisdiction of Objectives the City of San Diego. The objective of land use A regional program for watershed controls, as stated in Chapter One, management is critical to the long page 1-6, is to ensure that appropriate term preservation of the lagoon. A land use and structural design controls number of public agencies hold juris- and adequate erosion control measures diction over the various portions of exist to protect the lagoon resources the watershed, but an effort is neededI fromi the impact of development in to bring together the volumes of in- and adjacent to the lagoon. formation, previous plans, and the array of human and natural processes Land Use Controls into a coherent, focused watershed management plan with adequate land This plan assumes retention of exist- use controls. ing zoning in Del Mar, with the exception proposes extending appropriate zoning Association is currently preparing to the areas within the City of San a revised Master Plan which must be Diego and the county jurisdiction. compatible with this enhancement pro- gram and, when certified by the Coastal Design criteria and development Commission, will be incorporated into controls should be applied to a buffer the LCP for the City of Del Mar. The area surrounding the lagoon to protect preparation of the Master Plan has been coordinated with this planning effort 5-2 ~~~~~~~~~~~~~~and both projects should be mutuallyI supporting. zoning City of Del Mar Review of present zoning in Del open space", as stated in the City's Mar indicates that existing controls Zoning Ordinance. are adequate for the most part to protect the lagoon from incompatible A floodplain overlay covers the uses. The chart on page 5-5 summarizes portion of the NC Zone between Jimmy the zoning categories for properties Durante Blvd. and the railroad, re- located in the lagoon planning area. quiring a Conditional Use Permit and review by the City Engineer to assure Within the city limits of Del Mar, that development will not constitute the lagoon area between Turf Road and an obstruction to flood flow, nor San Dieguito Drive is zoned Floodway create a hazard to life, property or (FW) to prevent any uses which would public health, safety or general restrict or be damaged by flood flows. welfare. West of Jimmy Durante Blvd. the FW zone includes the main river channel The "railroad triangle", proposed and banks and spreads out at the rail- for the construction of the west tidal road to cover the low areas west to basin, is located in the NC Zone. In the ocean. The FW Zone coincides order to implement the proposal for essentially with the current County tidal basin construction, this parcel designation. If indicated by studies should be changed to the PP (Public currently being conducted by the Park) Zone at the time of public Department of Water Resources (DWR) acquisition or control. and the County Department of Sanita- tion and Flood Control, the FW designa- The fairgrounds/racetrack complex tion should be adjusted to coincide is covered by the FR Zone, leaving with a new floodway determined by those development decisions up to the 22nd studies. District Agricultural Association which owns the property. This Plan does The south side of the river on not propose a change in the FR designa- both sides of Jimmy Durante Blvd. is tion, but does find that recreation- designated North Commercial (NC) oriented uses in that zone shall be allowing low intensity commercial uses limited to those proposed in the 22nd which provide a service to the com- District Master Plan, as certified munity, "offering a lively open air by the Coastal Commission in the City commercial environment with substantial of Del Mar's LCP. 5-3 ~, i>~ Legend Foda Fairgrounds /Racetrack :~JCommercial LiiAgricultural CA.I1-O0) Med. Denaity Resid.(R110 LZZ " ~~Mixed C RM) 3 Low Resid. CR-1-20) liiVery Low Bonn. Ron. CM-1-4O) Railroad Open Space Overlay Floodplain Fringe san dileguito lagoon enhancemient -Dlan 9~~~~~~~~~~~~ City of Dal Mar, Ceiforr~Am State Coastal ConseOrancY 5-4I I ~ ~~~~~~~~~~~~~~~~~~~~~~ZONING DESIGNATIONS The lagoon viewshed west of San Dieguito Drive facing the river valley City of Del Mar to the southeast is zoned R1-40, appropriately allowing one unit per Zone._ acre of residential development. The FW Floodway designation for areas subject to relatively Bluff, Slope and Canyon (BSC) Overlay deep and high velocity floodwater; prohibits uses which seeks to preserve the scenic sandstone would impede the flow of floodwaters; requires conditional Use Permit for any uses. Allows aviaries, field and seed bluffs and canyons and steep slopes crops; aquaculture and mariculture operations; or open which characterize the area, while at recreational. Prohibits permanent structures. the same time protecting the public PP Public Parkland; for publicly owned land designated I from unsafe development. Clustering for use as a public park or open space preserve; and of structures is encouraged in the land which is subject to the Public Trust. Allows BSC Overlay Zone in order to minimize public parks and playgrounds, public openspaces, and I the visual impact of development on the ecological preserves; requires Planning Commission surrounding area. The City's Land review. Conservation Ordinance sets forth FR Fairgrounds-Racetrack; allows commercial recreation uses criteria and requires a discretionary on property owned by the State of California 22nd District criteria and requires a discretionary ~Agricultural Association. permit for any grading proposed in the City. The Buffer Area standards NC North Commercial Zone allows commercial activities that identified in this 131an reiterate provide a service to the community: development shall be design and grading controls on develop- of low intensity and profile, offering a lively open air commercial environment with substatntial open space; ment for the specific purpose of protect- allows retailing of goods, dispensing of services, and ing the lagoon resources. Such controls light manufacturing (exclusive of drive-thru). apply to the hillside as well as other R-10 privately owned parcels surrounding R-40esidential uses, one dwelling per ,000 or 40,000 the lagoon. square feet respectively. Overlay Descri pti on The 20-acre "Snakewall" property on the hillside is covered by an Open FP Floodplain; includes the 100-year floodplain area, except the Space Overlay, as well as the BSC portion within the actual floodway. Overlay. The site possesses significant Bsc Bluff, Slope and Canyon; provide special regulations for scenic values, and could be appropriate- control of development to preserve the scenic sandstone bluffs ly developed as an overnight visitor facility such as a youth hostel or a Ds Open Space; established to protect open space areas of professional retreat. If that were to community wide importance. Applies development criteria to occur, a change from the R1-40 Zoning specific par6els to preserve scenic vistas and unique natural wocculdberequird and sha roul te c Zonsid- features and to ensure an atmosphere of openness. (See Del would athe ruimed any prouldcbe conslder- Mar Community Plan for specific parcel criteria.) I ~ed at the time of any project applica- tion. However, the intensity of develop- ment currently allowed should not be exceeded. City of San Diego A major proposal for simplifying The area south of the floodway to management of the lagoon involves annexa- the bottom of the southern hillside tion of the City of San Diego land west slope is also currently zoned Al-10 for of Interstate 5. Recommendations for agricultural use. The Torrey PinesI zone changes presented here should be Community Plan of the City of San Diego carried out as part of the annexa- proposes an Open Space designation for tion process or, in the event that the area. As soon as public acquisitionI annexation does not take place, as part is completed, this land should be rezoned of the City of San Diego's LCP imple- to the PP Zone designation to permit mentati on. implementation of the various phases of enhancement work described in this Plan.I The commercial-recreation area south of Via de la Valle should be retained In the event that public acquisition in the current C (commercial) zoning is not completed, the Al-10 Zone shouldI This will allow continued visitor uses be retained and land uses limited to compatible with the adjacent fairgrounds/ apiaries, aviaries;, field and seed racetrack complex. crops, and aquaculture, with a minimumI parcel size not less than ten acres. South of this area, the 22nd District land between Turf Road and Interstate 5, The residential zoning on the hill- is zoned Al-10 for agricultural uses, side south of the lagoon should be changedI allowing one dwelling per ten acres to reduce the overall residential density for agricultural use. This area should currently permitted to a lower density be changed to the FR Zone to permit of two acres per unit, consistent withI only uses related to the recreational recent coastal development permit facilities at the racetrack. decisions. The buffer area development The F (Flodwa) Z o e inSan iegocriteria should be applied to the area The F (Flodwa) Zoe inSan iegowith controls that will protect the coincides with the County's designa- scenic values, insure that unsafe tion of the floodway with adequate de- development will not occur, and encourage velopment restrictions to prevent life clustering of development to reduceI and property loss. This zone would not impacts on the lagoon. change unless new County flood studies determine that flood lines should beI redrawn. 5-6 3 ~~County of San Diego The strip of land along the northern The small area of residential border of the fairgrounds/racetrack zoning (RV-ll) at the northwest complex is zoned A70-8 by the County for corner of the racetrack should remain I ~ ~~light agricultural use. Again, this as it is currently designated. The designation should be changed to permit Commercial Zone west of the railroad only recreation area Uses designated in is also appropriate, but should be I ~ ~~the 22nd District's certified Master Plan. subject to the standards described for the Buffer Area to protect the lagoon habitat immediately south of the * ~~~~~~~~~~~~~~developed area. City of San Diego D Zone Description FW Floodway coincides with the County's 100-year floodway de- signation. Permits only uses which will constitute an * unreasonably, unnecessarily or undesirably dangerous impediment to the flow of floodwaters. Allows: various agricultural uses; public parks and playgrounds; and park- U ing lots serving facilities in the floodplain fringe. Other relatively open uses are allowed with a conditional use permit. Restricts permanent structures. C Commercial uses, include restaurants, gas stations, recreational vehicle park. I ~~~~Al-10 Agricultural use; 10 acre minimum lot size. RI-20 M~edium density residential use. County of San Diego Zone Description I ~ ~ ~~C Commercial uses. A70-8 Agricultural use; 8 acre minimum lot size; usually applied in flood prone areas.0 RV-II Residential use, allows triplexes; minimum 4,000 squareE feet of land per dwelling unit. I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~5-75 buffr areasU (Proposed) Legend Reserve Lands Butter Areas -Intel~~~~~~~~~ A-M '~I san dieguito lagoon enhancement pa City of DeI Mar. California - State Coastal Conservancy As part of the land use re- 1) preservation of the habitat gulations, the City of Del Mar values of the reserve; should immediately designate the 2) protection of the water quality lagoon as an '"Ecological Reserve" in the reserve; I ~ ~and identify the surrounding area 3) preservation of the visual as a Buffer Area with development resource values of the lagoon criteria outlined below to be and its viewshed; and I ~ ~applied to it. 4) protection of the coastal bluffs. The ecological reserve status serves to identify the area which this I ~ ~plan seeks to enhance, and which will ultimately come under the management I of the Department of Fish and Game AEA I ~ ~pursuant to their definition in the AE Fish and Game code.0 The Bufer Areasurrouning theThe Buffer Area covers the slope ThesBfervAea isuroudeingnathed on the south and southwest edges of the 1 to protect the Reserve from the impact E ologica Reserve, from the nrhboundary of existing facilities and new develop- ofteRsre pt h orhbudr I ~ ~ment activities in immediately adjacent of the Crest Canyon Park Preserve on areas. After completion of Del Mar's the south, and to the top of the hillside LCP, Section 30603 of the 1976 Coastal on the southwest. On the south side Actstaes hatanyperit ordevelop- of the main river channel, the Buffer ment activities taking place within Area covers all of the property within 100 feet of the wetland can be appealed the study area south of the river bank to the State Commission. This plan between Jimmy Durante Blvd. and Camino establishes objectives and criteria de] Mar except the "railroad triangle" for evie of pplcatins wthinthewhich is designated a part of the I ~ ~designated Buffer Area, which includesrervitlf but is not limited to that 100 foot zone. North of the river channel, the Specific objectives of the Buffer Area Buffer Area covers the portion of designation include but is not limited land between the north bank of the I ~ ~to: river and the structures of the hO fairground/racetrack complex or * ~~~~~~~~~~~~~~its parking area. '5 PROTECTION STANDARDS FOR "The alteration should result THE ECOLOGICAL RESERVE in a minimum disturbance of existing or natural terrain, natural formation, and In order to ensure the pro- major vegetation. tection of the Reserve, and to ensure that potential develop- a. Development should be ment results in minimum distur- subservient to the topo-I bance of existing or natural ter- graphy of the site rather rain and vegetation and does not than forcing the topography create soil erosion, silting of to be subservient to the ing problems, or severe cutting b. Development shall ensure or scarring, all grading which that steep slopes are not takes place in the designated endangered by undue in- Buffer Area shall conform to the creases in weight or re- criteria set forth in Section taine'd water to avoid 87.212 of the Del Mar Municipal slippage of steep banks;I Code (Land Conservation Ordinance) c. Development shall avoid as follows: ~~~~~~~any alteration of natu- ral formations; Restora- tion of the natural siteI shall be encouraged: d. Development shall minimize the loss of vegetation:I e. Development s-hall not create major interruptions of natural drainage patterns." If the grading is to occur with-I in the jurisdiction of the City of Del Mar, a Land Conservation Permit shall be obtained from the City. All activities and development g. Retain the maximum amount I ~~taking place in the Buffer Area shall of native vegetation on the conform to these further standards: site and insure that all vegetation is done with a. Ensure that all runoff during natives, minimizing the new construction is retained need for irrigation; on site in settling ponds or h. Ensure that the value of the is percolated into the soil viewshed is protected by I ~ ~~~on site; or construct a run- incorporating the following off culvert to the lowlands criteria into the design of E with an adequate energy di-s- new developments: I ~ ~~~sipator to prevent erosion arid sedimentation into the 1). Compatibility of design lagoon; with the desired de- N M b. Ensure that drainage from veloping character of existing developed areas the surrounding area. causes no erosion or sedi- 2). Recognition of views, mentation into the lagoon; climate and the nature c. Ensure that runoff from of outside activities existing developed areas in the design of ex- does not carry toxins or terior spaces. I ~ ~~~~excess nutrients into the 3). Preservation of views lagoon channels; and scenic vistas from ' d. Ensure that all on-site unreasonable encroach- drainage patterns will occur ment. U ~ ~~~~on or through areas designed 4). In areas of rugged to- ' to serve this function; pography, design of e. Minimize the disruption of buildings to be sub -E I ~ ~~~~existing natural features servient to the natural such as trees, and other terrain. vegetation, natural ground 5). Consideration of views forms, and view; from the lagoon and f. Blend any proposed grading the freeway corridor with the contours of adjacent in the landscape and * ~~~~~properties; structure design. 5-11 1t I~~~~~~~~~~~~~~~~~~~~~~m THE NEED THE SAN DIEGUITO WATERSHED Watershed management is an Briefly, the lower San Dieguito essential part of wetland pre- River Watershed reaches from Del MarI servation. to Interstate 15 where the highway crosses the eastern end of Lake Wetlands are geologically Hodges south of Escondido, encom-I transitory natural phenomena passing all those lands west of (see Appendix D) due to continu- Interstate 15 with tributaries drain- ing infilling by the process of ing into the Sarn Dieguito River. watershed erosion. Eroded The total land of this lower water-I materials become streamborne shed is about 43 square miles. sediments, ultimately being deposited in river deltas and The entire watershed includingI wetlands where the water current the portion above Lake Hodges covers is too slow to continue carrying about 350 square miles and represents the soil particles. If left to approximately nine percent of San natural processes alone, this Diego County. The construction of "transitory" period is long. Hodges and Sutherland Reservoirs Indeed, it is human alteration of have essentially divided the water- and construction on the hills and shed into discrete units which inter-I valleys of the watershed that act only during years of heavy rain- accelerates the downstream move- fall which causes the reservoirs to ment of soil. Erosion from de- spill over their dams. This has velopment of the watershed is a occurred only twice in the last 26 threat to the coastal lagoon that years. The upstream area is a can ultimately negate all of the highly scenic and valuable wildlife public investments in the tidal habitat area but is undergoing heavyI wetlands through sedimentation. development pressure (e.g. the "North City West" proposal for a The City of San Diego has 40,000 increase in population). initiated a study of the San Dieguito River which should aid in the process of implementing the goals and objectives of Del Mar's Local Coastal Program and the Lagoon Plan, the Coastal Act 5-12 ~~~~~of 1976 and other plans. I ~~OBJECTIVES AND METHODOLOGY No outstanding example of Grades should be designed to produce I ~ ~a watershed management program runoff equal to the natural flow and exists in California, although to direct flows along natural some components are becoming drainage courses and through natural I ~ ~clearer. These are summarized terrain where the vegetation can below: cleanse and filter runoff waters. Paved surfaces should cover a mini- 1. Control of erosion and the mal area, to allow rapid and resulting sedimentation is the sufficient water infiltration into primary purpose and goal of the soil. The flow can be diverted watershed management. Reduc- through natural vegetated drainage- I ~ ~~tion of speed and quantity of ways and by use of suitable buffer r'unoff water is a primary tool. strips which provide for the cleans- 2. Increased sedimentation from ing of runoff water by providing E I ~ ~~careless construction prac- vegetative "scrubbing" and infil- tices seriously damages tration of water through the soil. streams. Construction can increase soil erosion by re- 3. Significant amounts of land may be moving vegetation which required for buffer strips, runoff stabilizes soil with its detention areas, groundwater re- roots, leaves, and organic charge areas, and other water pro-. debris; and by removing top- tection measures. However, creative soil, changing natural drain- use of such areas for recreation, age patterns, and leaving decorative purposes, or privacy large expanses of bare land screens will permit uses of benefit exposed to wind and running to the owners. 1 water. The amount of sediment eroded from areas undergoing 4. The higher the degree of development, I ~~~urban development can be far the greater the need to provide0 greater than from any other vegetated buffer along drainageways. major land use. Urbanization Riparian vegetation provides a highly can produce 20 to 200 times as vital and diverse wildlife habitat much sediment as farmland does. and acts to retard erosion from In site preparation, barren steambanks. I ~ ~~soils should be rapidly sta- bilized and revegetation and runoff detention implemented. ~~~~~~~~~~~~~~~~~~~~~~~~~~~IV 5. Farm operations in the water- shed must be well managed tol protect coastal ecosystems from damage by fertilizers, biocides, sedimentation, and altered runoff. Croplands and areas intensively used by livestock should be set back from watercourses to provide a naturally vegetated buffer area. Upland farm layout should minimize alteration of natural drainage and prevent water pollution. 6. Paved surfaces collect and channelize a broad variety of pollutants which are a major source of water quality problems. 7. Uplands around marshes may require seeding'and planting to develop a permanent vege- tation cover, provide upland nesting cover, and prevent wind and water erosion with resulting sediment deposition in the wetland. Appropriate agencies should incorporate these concepts into all plans, projects and regulations. 5-14 8. Secure agreement with the railroad for use of triangle parcel and'or initiate acquisition proceedings. APPENDIX A 2. PROPOSED ACTIONS FOR THE 22ND DISTRICT AGRICULTURAL ASSOCIATION PROPOSED ACTIONS FOR PUBLIC AND PRIVATE AGENCIES a. Ensure that the Racetrack Master Plan is fully compatible with the Coastal Act, the Del Mar LCP, and this Lagoon Enhancement . PROPOSED ACTIONS FOR THE CITY OF DEL- MARProgram; . PROPOSED ACTIONS FOR THE CITY OF DEL MAR b. Lease or contribute 12 to 15.9 acres within the supplemental parking area (Area VI) to the City of Del Mar or DFG for manage- a. After public hearing, adopt this San Dieguito Lagoon Enhancement ment as a least tern habitat preserve. Plan and initiate the approval process: c. Assist the City of Del Mar in conducting soil core analyses at 1. Declare the lagoon to be an "ecological reserve". soil extraction areas. If suitable, receive maximum possible 2. Submit the adopted Plan to the Coastal Comnission as part of amount of spoils from the lagoon for use in the construction the City's Local Coastal Program. phases of the Master Plan and share in costs by purchasing the 3. Seek endorsements from the City and County of San Diego. soil at below-market price. d. Conduct a cleanup and beautification effort along the edges of b. Initiate implementation of Phase One as lead agency. the lagoon, including removal of rubble along water edges. 1. Appoint a staff person lagoon project coordinator and retain Maintain these areas free of such accumulations in the future. the lagoon committee for assistance. e. Develop with DFG, SCC, and Del Mar a cooperative agreement 2. Initiate annexation of the lagoon area west of Interstate 5 regarding the Least Tern area and the disposition of excavated within the City of San Diego and south of Via de la Valle within the City of San Diego and south of Via de lia alle soil within the race track construction areas and on Area VII. within the County of San Diego. Extend appropriate zoning in the Del Mar area to the balance of the lagoon. 3. PROPOSED ACTIONS FOR THE CITY OF SAN DIEGO 3. Improve the security of the gate at Grand Avenue Bridge as a temporary improvement until the permanent entrance gate is a. Endorse the San Dieguito Lagoon Enhancement Plan by resolution constructed. of the City Council. 4. Establish an abatement program for any nuisance structures and b. Ensure that the pilot watershed/erosion control plan and program safety hazards in the lagoon area. for the San Dieguito River basin below Hodges Dam fully protects 5. Execute an agreement with the California Conservation Corps for the lagoon from controllable sedimentation. ongoing assistance in implementation of all phases. c. Accelerate completion and implementation of the Crest Canyon 6. Jointly with the Coastal Conservancy prepare a work program and erosion control plan with the assurance that further sedimentation flow chart for the execution of Phase One including the follow- into the lagoon will be halted by modification measures (e.g., a ing tasks: culvert leading to an energy dissipator and sediment basin at the o Plan and supervise the least tern habitat enhancement work: foot of Crest Canyon). o Organize and publicize citizen involvement efforts; d. Authorize annexation to the City of Del Mar of all San Diego City o Secure approval to enter State lands for debris removal land west of Interstate 5, north of San Dieguito Drive, and south from waterways and mudflats; of Via de la Valle o Secure approval and assistance of private landowners for cleanup efforts; 4. PROPOSED ACTIONS FOR THE COUNTY OF SAN DIEGO o Secure a California Conservation Corps workforce to accom- plish the cleanup and supply needed equipment; a. Endorse the San Dieguito Lagoon Enhancement Plan by resolution of o Abate nuisances and safety hazards in the lagoon buffer area; the Board of Supervisors. o Design informational signs for placement at lagoon access b. Cooperate in the City of San Diego's pilot watershed erosion plan points; and program for the San Dieguito River basin below Hodges Dam. o Install a temporary gate for the Grand Avenue Bridge that c. Authorize annexation to the City of Del Mar of all unincorporated will resist vehicle trespass; and land to the north of the existing Del Mar City limits between Turf o Design a permanent gate for the Grand Avenue Bridge and a Road and Camino del Mar up to Via de la Valle. kiosk at the intersection of Ji=nWm Durante Boulevard and San Dieguito Drive to serve as the entrance to the "San 5. PROPOSED ACTIONS FOR THE STATE COASTAL CONSERVANCY Dieguito Lagoon Ecological Reserve" (part of the citizen involvement process). a. Endorse the plan in concept, submit the Enhancement Plan (Chapter III) to Coastal Commission for approval, and then authorize implementa- c. Initiate steps necessary for implementation of further phases of tion of Phase One with a grant to Del Mar of up to $10,000 for the project. administration of work and monitoring plus $60,000 for construction of 1. bfith assistance from the 22nd District Agricultural Association, site improvements in Phase One. conduct the necessary soil core samples to confirm suitability b. Authorize staff to assist the City's lagoon project coordinator as of lagoon soil for construction uses. needed to ensure timely implementation of all phases. Prepare work 2. Subrmt this plan to the U.S. Soil Conservation Service or program for Phase One with Del Mar. Army Corps of Engineers for determination of the eligibility of c. Co ordin at e multiple actions necessary to implement the program and Phase Six (river channel dredging) as a "small watershed project", establish a lagoon monitoring and maintenance effort. pursuant to P.L.566, or as a "small flood control project". C 3. Execute a long term lease with the City of San Diego for use of the abandoned sewage oxidation pond (Area VIII). 6. PROPOSED ACTIONS FOR THE CALIFORNIA COASTAL COMMISSION 4. Secure agreement with the Del Mar 88 for access across their land to the abandoned sewage oxidation pond (Area VIII) for construc- a. Find that the Coastal Conservancy's San Dieguito Lagoon Resource tion and maintenance activities. Enhancement Plan (Chapter III of this document) is consistent with the Coastal Act of 1976. 5. Determine wind and machinery constraints affecting the capability b. Approve the lagoon regulatory provisions in the Del Mar LCP (based of windmills to deliver enough replacement water for the fresh- on teo proposals in Chapter V of this document) and ensure that no water marsh (Area VIII). major development occurs in the,a)ea of annexation until the process 6. Evaluate Fairgrounds Master Plan and Crest Canyon Erosion Plan has been completed and Del Mar or San Diego has established appropriate zoning f~or these areas. for consistency with the Del Mar LCP and Lagoon Plan. 7. Prepare a cooperative agreement with DFG regarding management c. If new submittals or reapplication for permits in Area XI are made, tained, including: 1. mitigation of impacts of widening San Dieguito Drive; 2. sale of lagoon bottom land at appraised value to WCB; 10. STATE WATER QUALITY CONTROL BOARD AND REGIONAL WATER QUALITY CONTROL BOARD 3. buffering of the lagoon from human and domestic animal intrusion along the north boundary of development. a. Authorize Phase One channel work through a NPDES permit. b. Authorize freshwater marsh filling (Phase III) through a SWRCB 7. PROPOSED ACTIONS FOR THE DEPARTMENT OF FISH AND GAME AND THE STATE approval to appropriate water. WILDLIFE CONSERVATION BOARD 11. PROPOSED ACTIONS FOR FEDERAL AGENCIES a. Endorse this Lagoon Enhancement Program through a letter from the DFG Director with clarification of what DFG funding is avail- a. Corps of Engineers able. 1. Issue a Section 10/404 permit for the Phase One channel b. Issue Section 1601-1603 streambed alteration agreements for Phase modification work to be conducted by the California Con- One channel work. servation Corps in conjunction with the State Coastal c. Expedite lagoon land acquisition by MCB to permit the initiation Conservancy and the City of DSta te Coastal of Phases Two and Four in a timely fashion. Conservancy and the City of Del Mar. 2. Closely monitor the timely solution of the Crest Canyon sedi- d. After l and acquisition and prior to solicitation of bids for the 2C lsy fan Situation to corrt the Crest Canyon sedi- engineering work, determine what DFG equipment and personnel within a waterway. would be made available to work on the projects. Determine i tf would be made available to work on the projects. Determine if 3. Review the overall project phasing and advise Del Mar and the new equipment should be purchased. e. Execute a cooperative agreement with the City of Del Mar for 4. Determine if Phase concerns over Section 10/404 permits 4. Determine if Phase Six (river floodway dredging) qualifies management of the lagoon. as a small flood control project. f. Jointly with the Coastal Conservancy, prepare an analysis of the comparative costs, constraints and advantages of heavy equipment b. U.S. Fish nd Wildlife Service used in wetland and waterway work to permit a timely implemen- tation of Phases Two and Four when the land is acquired. 1. Support issuance of Section 10/404 permits for Phase One g. Upon purchase of the coastal dunes at the mouth of the river, set channel modifications on the finding that the manual aside appropriate acreage for a dunes natural vegetation preserve excavations of presently stagnant and shallow channels in the (with assistance from the CCC). Salicornia marsh of Area IX-B and Area X-C will be h. Develop with Del Mar, the CCC and/or University scientists, a beneficial. procedure for determining when a closed lagoon mouth requires manual openings and if high tide levels require emergency closing c. Soil Conservation Service of the mouth. Determine if Phase Six (river floodway dredging) would qualify as a PL 566 "Small Watershed Project" and facilitate application 8. PROPOSED ACTIONS FOR THE CALIFORNIA CONSERVATION CORPS (CCC) for funds by the City of Del Mar. a. Endorse the plan as a long-term joint implementation project with 12. PROPOSED ACTIONS FOR EDUCATIONAL INSTITUTIONS AND THE PRIVATE SECTOR the Conservancy and Del Mar. b. Schedule adequate personnel from the Escondido Camp to assist the a. University of San Diego and University of California at San Diego City of Del Mar in implementing Phase One in early spring 1980, with work to include these activities: 1. Share with DFG and Del Mar the ongoing monitoring of biological 1. Hazard and rubble removal from public lands and waterways. productivity and water quality in the lagoon, with special em- 2. Deepen channels in Area II to improve tidal flushing and phasis on determining when prompt action is needed to open the reduce human intrusion. lagoon mouth. (any sampling, other than with live cages, must 3. Assist in removing sand from the Crest Canyon alluvial fan receive Del Mar City Council approval until a DFG - City (Area XII) for covering the least tern habitat (Area VI). cooperative agreement establishes other means of approval or 4. Improve existing channel through Area X-C for winter rain practices.) water runoff and unrestrained ponding (if land is acquired). 5. Improve existing channels within marsh in Area IX-B without 2. Jointly with citizen public interest groups, and Del Mar - alteration of Salicornia. Place sand on existing barren DFG concurrence, sponsor guided tours of the lagoon as salt flat sites and contour into nesting islands. project phases are implemented, to promote understanding of 6. Construct a lagoon viewing station and mini-park next to the the ecological significance of, and need for, physical alter- Highway 101 Bridge with contributed materials. ations to the channels and the overall lagoon's processes. c. Through an agreement with DFG, Del Mar, and any advising b. Public Interest Groups University scientists, establish an experimental program for manual (or with a contributed tractor) opening of the lagoon i. Work with educational institutions to conduct educational mouth within one week after it is decided the marine environ- tours and conduct resource monitoring, as proposed above, ment is in jeopardy. With specialists' guidance, maintain as well as to improve policing of the lagoon. records of the frequency of this work, time needed, duration of 2. Develop a "San Diego Lagoon and Wetlands Trust" (similar open mouth, and ecological results. to the San Elijo Lagoon Foundation) which can purchase lands, accept dedications, and provide management services 9. PROPOSED ACTIONS FOR THE STATE LANDS COMMISSION AND DIVISION in coordination with the appropriate governmental agencies. a. Endorse the Lagoon Enhancement Program in concept and authorize improvements (as "maintenance" work not requiring specific permits) of the public waterways for all phases of the project. b. Determine if Area IX-A (marshy area at the juncture of the North Channel and the South Channel) is State land and available for near-future improvements by the CCC, as part of Phase One. c. Accelerate public lands and Public Trust determinations. A-2 Tasks: l) Release information about lagoon and the project and APPENDIX B ___ investigate interest in a citizens' foundation for the lagoon. PHASED IMPLEMENTATION OF SITE CONSTRUCTION WORK 2) Conduct a spring cleanup program (see Section e. below) 3) Design the Lagoon Reserve Entrance and informational kiosk (see Section g. below) with civic groups and high schools encouraged to propose designs. 4) Design "San Dieguito Lagoon Ecological Reserve" signs, l. Introduction which are non-obtrusive and provide information about the resource area, as well as request no trespassing The following section is a detailed outline of the many work activities or littering. necessary to create the project design proposed in Chapter III. The 5) Solicit contributed materials for bench, viewing site, sequence of phases may be altered but reasons exist for their chrono- and sign construction. logical progression, as noted in Chapter IV. logical progression, as noted Chapter IV. Environmental Impact: A higher level of public awareness about the The description has been organized into an outline and list format develop, especially through media attention. to facilitate cross - reference and comparison. Its sections are: Signing will be non-obtrusive and encourage voluntary Objective; Location; Lead Agency; Prior Actions Needed; Estimated Cost reduction of trespass and littering. (the estimated cost of land acquisitions have not been provided to avoid future complications of negotiations); Equipment (which now seems the � Fiscal Impact: City costs will be in staff supervision time. Media most probable or suitable for the nature of work); Tasks (those actions coverage is anticipated to help communicate the program needed to achieve the work objective); Concerns (problems, issues, to the public. A good response can reduce governmental constraints); Environmental Impact (and mitigation); Fiscal Impact (the expenditures by providing design concepts, work assi- cost to the public and possible reductions). stance, and contributed materials (for use by the CCC in the construction phases.) 2. PHASE ONE: Remedial Actions, Habitat Improvement and Public Involvement c. LEAST TERN HABITAT ENHANCEMENT a. Overview Objective: Protect and enhance an area of critical importance to This phase is designed to permit some of the enhancement work to the endangered least tern. be initiated quickly, even before all the land is acquired by the � Lead Agency: Del Mar, with 22nd District support, and Conservancy Wildlife Conservation Board (WCB). Although some channel work grant. in public trust areas will require a Section 10/404 permit from t Am in publ i c trust areas will require a Section 10/404 permit from � Location: Fairgrounds overflow parking area, 16 acres (Area VII). the Army Corps of Engineers (COE), most of the work will not � PriorActions Needed: Agreement with 22nd District. require such a review. The City of Del Mar is the lead agency and tstimated Cost: 1) Land: contributed or exchanged. will be supported in most of the components with advice 2) Fencing (130 yards): $1,755. and assistance from the California Department of Fish and Game (DFG); 3) Sand: free from Crest Canyon alluvial fan. and assistance (qrants and in-lieu contributions) from the State 4) Use of skip loader for loading; city trucks Coastal Conservancy (SCC) and the California Conservation Corps(CCC). to carry sand (2 mile round trip); bulldozer The components of this phase are: public involvement program; to smooth sand = $2000 for rental one month, least tern habitat enhancement; minor channel and water circulation with labor contributed by CCC, DFG, and the improvements; cleanup of waste; construction of permanent entrance City. to lagoon reserve and information kiosks; and improvement of controlled Tasks: l) Erect additional fencing (30 yards) to c lose access and recreation. gaps in existing fence and to reach the water's edge. b. PUBLIC INVOLVEMENT PROGRAM 2) Transport sand from Crest Canyon alluvial fan to spread evenly over the parking lot, providing an attractive substrate for least tern nesting. Objective: Provide public education about values of the lagoon. an attractive subve getat on as neessary encourage private sector contributions of materials. Concerns11 The present 15.9 acre parkingarea belonging Lead Agency: Del Mar and its citizens' committee. Location: Not applicable, except in certain sites for special D rante Blvd is straightened projects. acres if Jimmy Durante Blvd is straightened Prior Actions Needed ein association with the construction of a new B MlW Prior Actions Needed: Appointment of Del Mar Coordinator; award bridge. The fairgrounds would benefit from -of Conservancy grant to the City for administration. improved traffic circulation and, with the de- Estimated Cost: In-kind services (City of Del Mar staff time and velopment of an alternative parking sit the velopment of an alternative parking site to the citizen contributions of time and materials). east could be expected to assist in mitigation Equipment: Not applicable of the roadway's impact. of the roadway's impact. I W Through the environmental documentation to be 2) Remove soil to presently sterile locations or salt prepared for the federally funded work, an flats which can he enhanced as nesting islands. arrangement would be made for establishing the � Concerns: 1) The three areas have the common characteristics remaining 12 acre area as a least tern preserve. of being well covered with Salicornia (pickleweed) The Fairgrounds Master Plan could expedite the with inter-twining small, sediment-filled channels execution of this mitigation. which, if excavated, can improve tidal flushing 2) Study of least terns hac indicated their pre- and water quality. ference for nesting in wide-open areas without 2) Crews must avoid damaging Salicornia. vegetation, on white sand littered with sea o Environmental Impact: The primary benefits would be shells, and at a location adjacent to water for improved water circulation and less stagnation. ready feeding. The sand from the Crest Canyon Removal of material within the waterways can disrupt fan is light colored. However it is supporting fish habitat and cause localized turbidity, but a regrowth of vegetation which must be retarded. with only manual labor there will not be much capability to extend the work very far into the water. DFG will 3) Contribution of trucks, skip loader and bull- be asked to identify snags, etc. which should be retained. dozer should be sought during the period of en- Flotsam and litter cleanup along the water edge would vironmental assessment of the road alignment be beneficial to wildlife which can also be injured by (prior to land reservation). these materials. Work would be done before Least Tern breeding starts. o Environmental Impact: The impact of possibly severing 3 acres from the � Fiscal Impact: City staff time would be necessary to plan 15.9 acre habitat area is mentioned above. However and supervise this effort. The 22nd District and the placing the great majority of land in preserve status State Lands Commission, as well as DFG, would have to be with fencing and ground cover improvements will sig- aware and supportive of the effort, but no significant nificantly improve the habitat. It should be noted costs would accrue to these agencies. Trucks, gas, that there is no guarantee the least tern will nest drivers, tools, etc., would be from the City and any in this area. However, historical usage and the proposed commercial sponsors, while the majority of work hours improvements suggest a good probability. would be provided by the CCC. � Fiscal Impact: Del Mar and DFG will have to provide staff supervision CLEANUP OF WASTE: but the cost of fencing and trucks can be secured � Objective: Visual improvement and reduction of hazards. through grants and contributions. .� Lead Agency: Del Mar with CCC support. �IOCNN Location: Throughout the lagoon, on public lands, public d. MINOR CHANNEL AND WATER CIRCULATION IMPROVYEMENTS Locatio trust waterways, and any private lands for which the owner provides permission to enter and assistance. � Objective: Following existing configurations, improve water cir- o Prior Actions Needed: CCC/Del Mar agreement; appointment of Del Mar culation through marshy areas without disturbance of the Lagoon Coordinator. ~~~~~~~~~~Salicornia.~ Estimated Cost: In-kind services. � Lead Agency: Del Mar with CCC assistance Euipment: Trucks, hand tools, possibly a winch. � Locations: I) Adjacent to the east side of Camino del Mar Tasks: 1) Cleanup of litter by volunteers, with possible bridge, leading to the northern pond and part-time work by probationers. Salicornia marsh (Area II). 2) Cleanup of waterway snags and safety hazards by CCC. 2) Within the Sal icornia marsh at the juncture i of the main river channel and the south channel value or bird roos ting (e.g. blue h erovide h abitat (Area IX-B) to be retained. DFG advice is needed. 3) In the southeastern corner of the lagoon, where 4) City to begin abatement of safety hazards and fresh water runoff in winter creates a temporary nuisances around lagoon. marsh (Area X-C) � Concerns: 1) State Lands Commission to be informed by letter of � Prior Actions Needed:'State Lands Commission finding of Public Trust; work along public trust waterways. Del Mar/CCC Agreement; "NPDES" permit from RWQCB; 2) Cleanup to be orchestrated as part of the citizens ovFG S etion 1601, Streambed Alteration Agreement; involvement program by City Lagoon Project coordinator, Estimated Cost: Approval of CEA negativcontributed equipment. with the major efforts in Spring 1980. � Estimated Cost: Labor by CCC with City contributed equipment. 3) CCC cannot work on privately owned lands, but can be � Equipment: Trucks for soil removal; shovels; wheel barrows; especially helpful in the water areas. Can work in mechanical ditcher. � Tasks: 1) With manual labor, clear presently sediment- pub4) i trust areas.moval and site for filled channels and create some new channels in disposal. three selected locations. 5) Work must be planned and supervised to avoid e Concerns: 1) Project is dependent upon willingness of Santa Fe Rail- disruption of wildlife and vegetation prior road to lease, donate or sell the parcel. to the April nesting season of the least tern. 2) New water surface of 3 acres can improve the lagoon's 6) Litter cleanup must be periodically repeated. overall tidal prism by about 10%. � Environmental Impact: The benefits would primarily be visual improvement and reduction of public safety risks. 0 Environmental Impact: No adverse impacts are predicted. The Removal of material within the waterways could Improvement of the overall lagoon's tidal prism is significant temporarily disrupt fish habitat and cause and the increased water surface and mudflat is beneficial to localized turbidity, but with only manual labor wildlife. In addition, the improved tidal fTushing will eliminate there will not be much capability to extend the mosquito breeding problems which occur when standing water builds work very far into the water. DFG' will be asked to up in the depressed area. identify snags, etc. which should be retained. Flotsam and litter cleanup along the water edge o Fiscal Impact: As noted above, various arrangements can be would be beneficial to wildlife which can be injured made to reduce the overall cost for this effort. Ongoing by these materials. Work would be done before least maintenance is expected to be minimal but the pipe will have tern breeding starts. to be occasionally cleared. The adjacent Public Works Department Fiscal Impact: City staff time would be necessary to plan and of the City of Del Mar can assist in this effort. supervise this effort. The 22nd District and the State Lands Commission, as well as DFG, would have g. CONSTRUCTION OF INFORMATIONAL KIOSK AND PERMANENT ENTRANCE TO to be aware and supportive of the effort but no LAGOON RESERVE significant costs would accrue to these agencies. Trucks, gas, drivers, tools, etc., would be provided Objective: Provide an entrance to the lagoon which will attract by the City and any commercial sponsors, while the and inform the public, drawing attention to the ecological values of majority of work hours would be provided by the CCC. the reserve while preventing unauthorized access into the habitat area. f. CONSTRUCTION OF SALT WATER TIDAL BASIN o Lead : City of Del Mar O Locations: ) entrance gate at intersection of San Dieguito Drive/ � Objective: Creation of a tidal basin and mud flat . in. an unused Grand Avenue; 2) informational kiosk on City property at San Dieguito lot owned by the AT&SF Railway Co. to increase tidal prism and Drive/Jinmy Durante Blvd. intersection. enhance wildlife habitat. � Prior Actions Needed: Publicity campaign; Del Mar/CCC work agreement. ' Lead Agencies: Del Mar and Conservancy � Estimated Cost: In-kind services and contributions. Location: Railroad triangle (Area IV), 3.5 acres Eouioment needed: Truck for delivery of materials; tools for Prior Actions Needed: Dedication, lease or sale of surplus railroad construction. land by AT&SF Railway Co. to the City; Section 10 permit from COE; � Tasks: 1) Entrance gate � approval of CEQA negative declaration. a. CCC will build gate structure with materials Estimated Cost: Pipe from basin to river channel to permit tidal provided by the community. flushing is estimated to cost $17,000. The movement of soil (17,000 2) Kiosk cubic yards) could cost up to $34,000 if the work is contracted a. City to conduct a design competition for construc- commercially; less if it is accomplished concurrert with Phase 2 or 3, . tion of the Kiosk. sharing equipment; or if CCC & DFG crews can assist. b. CCC will build the structure with materials pro- vided by the community. Equipment: If the pipe is installed by commercial firm, the re- maining work can be accomplished by tractors alone, with the buffer � Concerns: l) Entrance gate berm incorporating all the spoils. If excess spoils result, trucks a. The gate must be designed to withstand aggres- must be used for removal and a site selected (preferably at adjacent sive vandalism and forced entry. Sheriff's O City-owned lot now used for soil storage). Department must increase surveillance of the Tasks: 1) Excavate the triangle to an elevation of -0.5 feet b. Grand Avenue will be the major thoroughfare for to allow adequate tidal flushing. trucks carrying soil out of the lagoon during 2) Install a pipe connecting the new tidal pond with the Phase Two. Therefore, the gate must be designed l west channel of the river. to permit movement by the largest trucks. Large 3) Reconstruct the berm on the south side of the triangle mechanical equipment (such as dredgers) may have as a buffer from the adjacent commercial development. to be moved over the bridge -- therefore any Use spoils for berm material. crossbeams (for lagoon name identification, etc.) must be readily removable. qB- B-3 �Fiscal Impact: Labor for improvements will be carried out by 2) Kiosk CCC crews; materials for benches and signing will be provided by the a. The structure must be visually attractive but City and/or contributed by local fund raising projects. If designed to withstand vandalism. volleyball nets or other equipment were provided, there would b. Design the kiosk to include educational material be some materials cost to the City. City maintenance crew time about the lagoon and its wildlife. would be needed for clean up and trash removal. o Environmental Impact: Intrusion will be reduced. Public education 3. PHASE TWO: Northern Tidal Basin Development benefits will be secured. � Fiscal Impact: The in-kind services and citizen assistance will Objective: Enhance the wildlife habitat values of this area by make this a project requiring no grants. construction of tidal basins and marsh areas. Lead Agency: Department of Fish and Game h. IMPROVEMENT OF CONTROLLED PEDESTRIAN ACCESS AND RECREATION Location: The abandoned 9-acre sewage oxidation pond (Area IX-C) on the Del Mar 88 property (102 acres. including Grand Avenue, � Objective: Control public access to sensitive habitat areas while the abandoned airfield, and foundation remnants of the former industri- enhancing and facilitating access in areas where it would not conflict al structures (Area IX)E with protection of natural resources. Prior Actions Needed: Focused EIR; Section 404 and Section 10 permits � Lead Agency: City of Del Mar from COE. o Locations: l) south banks of west and north river channels; 2) north east Estimated Costs: $200,000 fer tidal basin construction (89,000 cubic of Camino del Mar at the San Dieguito River; 3)enhanced least tern yards' to he leloved), plus land acqtlisiLion costs. nesting area (Area VI). Equipment: Swamp cat, trucks, and probably a dragline, to create o Prior Actions needed: Grants of easements for all locations still tidal pond and channel. under private ownership; work agreement with CCC; completion of least Tasks: I) Secure public ownership by WCB tern nesting area enhancement for use as off-season recreation site. 2) Reconstruct levees for tidal marsh using swamp cat o Estimated Cost: in-kind services and contributed materials result and possibly a dragline. in negligible cost; labor would be contributed by CCC crews. 3) Excavate channel connecting tidal marsh to south o Equipment: hand tools for trail construction; construction tools river channel, parallel to Grand Avenue. for building bench at lagoon overlook. 4) Clean up and remove debris on airfield site (to be "Tasks: l)retain the pedestrian accesswayalong the south bank of the managed by DFG and carried out by CCC). river channel between Camino del Mar and Jimmy Durante Blvd. 5) Revegetate airfield with upland species, including Post signs for pedestrian access. trees to provide a possible rookery. 2)Construct a bench for pedestrian use on the north side of the river channel, east of the highway, overlooking Concerns: 1) High cost of project must be reduced (use of State- the lagoon (Area II). Build informational sign into owned equipment; possible private development trade- the bench. offs) 3)Police commercial activities along the south bank of 2) If dragline is used, protect pickleweed. the river east of Jimmy Durante Blvd. Insure that 3) 89,000 cubic yards of earth in basin and 14,000 from dumping of waste into the river is discontinued. connecting channel must be properly disposed of 4)Improve trail along bank south of the river and east (preferably at Fairgrounds) of Jimmy Durante Blvd. Post signs for pedestrian access. Environmental Impact: Construction of additional tidal pond area will 5)Encourage use of least tern nesting site for off-season have a beneficial impact by increasing the tidal prism and tidal (September through Mtarch) sand lot - type sports such as flushing and the amount of water surface available for waterfowl. volleyball, frisbee, golf. Provide City equipment for Fiscal Impact: This phase requires extensive expenditure of public such uses. funds by WCB and/or other public agencies. Funding may be available 'Concerns: 1) Off-season use of the least tern area may make from the Capital Outlay Fund for Public Higher Education (COFPHE). difficult the prevention of access during the nesting season. Public cooperation would be essential. 4. PHASE THREE: Fresh Water Marsh 2) Increased public use may increase need for local police and maintenance of the recreation areas. Objective: Create a fresh water pond and marsh, with water replenish- �Environmental Impact: Facilitates public access in least sensitive ment from groundwater pumped by windmills. areas. wtlI not impact on sensitive habitats; would increase public Lead Agency: City of Del Mar, with Conservancy support recreational opportunities in close proximity to existing facilities. Location: Northeast portion of lagoon in abandoned 14-acre sewage Off-season use of the least tern area may provide a beneficial oxidation pond (Area VIII). maintenance function by preventing growth of vegetation which would Prior Actions Needed: Lease agreement with City of San Diego; harbor predators, and by churning up the substrate, making a better arrangement for access to pond from Grand Avenue; approval of surface for tern nesting. SWRCB for extracting water from the river. Estimated Cost: Two windmills (including installation): $17,200; Pumps for extraction of 70 acre-feet of water from the San Dieguito river supplied by Del Mar B-4 e Equipment: Bulldozer and windmills. Possible future addition of aeration system to be powered by windmill. system to be powered by windmill. 5. PHASE FOUR: Southern Tidal Basin Development o Tasks: 1) Repair levees and clear vegetation from the bottom of the pond. Objective: Enhance the wildlife habitat value by excavation of tidal 2) Create (by bulldozer) two small islands before filling the ponds and mudflats, creation of a new marsh, and.channel construction pond, approximately 1/4 acre each in area. to ensure adequate water circulation and increased tidal prism. 3) Excavate ditches in the bottom of the pond to impede growth Lead Agency: Department of Fish and Game o Location: The southeast portion of the lagoon(Moshtaghi property-Area X) 4) Extract 70 acre-feet of water from the San Dieguito River to including the "fishhook" and the Crest Canyon alluvial fan (Area XII). fill the marsh. o Prior Actions Needed: Focused EIR; COE Section 404 Ipermit; fan removal. 5) Erect two windmills to replace water loss, expected to � Estimated Cost: From about $270,000 for dredger woi,-6hot c6unting the be about 42 acre-feet per year plus an unknown amount of costs for spoils disposal and mitigation of adverse impacts) to $425,000 seepage. for dragline/swampcat/bulldozer work (184,700 cubic yards to be excavated;) o Concerns: A variety of periodic manipulative practices may be required to The latter cost can be reduced with State personnel doing all but dragline keep the marsh and pond productive and inoffensive to residents work and purchase of dredge spoils by the 22nd District at low rates. in the area. These include the following considerations: EIR would he prepared by DFG staff. ) Emergent vegetation e.g. cattails) may become very Tasks: I) Secure public ownership of all of the project area. 1) dense, despite manaergement efforts. This problem may 2) Excavate "fishhook" channel and continue it north and back dense, despite management efforts. This problem may toward the west to join with the South Channel south of be remedied by periodically adding large quantities Grand Avenue. be remedied by periodically adding large quantities toward the west to join with the South Channel south of of salt water to the pond--cattails are generally Grand Avenue. intolerant of salt water to the pond--attais are generay 3) Dredge 16 acres east of new portion of channel to elevation 2) Emergent vegetation and mosquitoes may also be controlled of 0.0 feet, creating a new tidal pond, marsh aid eudflats. by periodically drying the pond. Total drawdown can 4) Using manual labor, excavate narrow channels criss-crossing by pe riodically drying the pond. Total drawdown can further eliminate bottom stagnation through aeration the new "island" (Area X-B), to increase marshy character of of sediments the area. of3) As neediments. bird carcasses from the 5) Spread sand from the alluvial fan on a 1 to 2 acre portion pond is essential to minimize botulism outbreaks in of the new "island" creating potential least tern nesting waterfowl. Total pond drying can alleviate this problem. habitat. 4) Public Health Department personnel may need to apply 6) Using hand labor or small equipment (e.g. trenching machine), certain control methods on the pond if mosquito populations Improve the channel across the southern boundary of the reach excessive numbers. lagoon to improve water circulation and pending for fresh 5) Periodic cleaning of equipment will be required. Monitoring water marsh. of evaporative losses and filling rates, with appropriate 7) When both tidal basins are completed on either side of Grand machine manipulations, will also be necessary. Avenue, a pipeconnected to both will be laid underneath the street, o Environmental Impact: The close proximity of a fresh water marsh to salt to ensure tidal flushing and water circulation. water environments will greatly increase the overall productivity of the Concerns: 1) This phase is contingent upon the acquisition of the lagoon. The availability of fresh water can also attract a greater duck Moshtaghi property by WCB and is also distinct from the prior population and provide many species with a preferred source of drinking water. phases due to the need for heavier equipment (Phase Two may No rare or endangered plants or animals are currently found within the basin. need a dragline but can apparently be done without a dredger). Vegetation will have to be scraped out before filling with water, and some This phase requires at least a dragline and may also call for reptiles and small mammals (such as rabbits and mice) will be displaced. The a dredger to achieve economy of scale. However the 12 and 16 lagoon contains substantial upland area (even after all rehabilitation work) inch dredgers continue to p ose problems of massive soil that will accommodate this small population. The windmills also offer a disposal. As this phase is nears inilementation (following land nonconsumptive energy source, which will be highly visible to the public on acquisition), the bids for engineering proposals will become the decision-making vehicle for determining which level of Interstate 5 and to lagoon visitors.Sh equipment is necessary. By this time it is possible the DFG o Fiscal Impact: If the fill-up water can be secured from the adjacent river equipment is necessary. By this time it is possible the DFG furing high volume winter flows by use of City-supplied pump, then a major will have increased its equipment pool for this kind of work . will have increased its equipment pool for this kind of work. cost of this project will be avoided. (Today's prices for potable water 2) The consultants' proposed site for this basin and furing high volunle winter flows by use of City-supplied pump, then a major 2) The consultants' proposed site for this basin and cost Of this project will be avoided. (Today's prices for potable water mudflat complex was in the southern part of Area X. However during the review process, DFG noted that substantial winter rain runoff passes through this area, coming from a culvert at this lower elevation before percolation and spill into the fishhook channel DFG feels this area has important values for migrating waterfowl. B-5 Therefore, the site for-the basin has been shifted to the north closer t6 Grand Ave. While this change will require additional soil removal, about 50,000 cubic yards (the new site being 1'2-2 feet higher in Environmenta Impact: Improvement of the habitat quality would enhance elevation than the old site), the change also puts the the valu the the area for use by wildlife species. Construction of basin closer to the existing road and thereby reduces the a boardwalk and fencing in the dune area would protect the fragile length of temporary road needed for trucks to reach the habitat from inpacts of human disturbance. soil dumping sites, making excavation somewhat Fiscal Impact: Materials, initial labor costs and ongoing management si impler. would be absorbed by the management agency. Some or all of the With the extension of the Fishhook Channel north end materials for construction of the boardwalk could be donated by west and its connection to the Souih Channel, not 'local citizens or groups. only will water circulation and the tidal prism only will water circulation and tile tidal pIrismn 7. PHASE SIX: Long Range Flood Channel Improvements be improved, but the enclosed area of 15 to 20 acres should quickly revert to marshy status. If it is slow I in doing so, some minor manual labor by the CCC can Objective: Improve flood protection and lagoon stability be clearing cre'jte the small1 channels necessary to ensure a marshy the channel and reducing friction on the tidal flow. condition. _Lead Aency: City of Del Mar Environmental Impact: This phase is essential for improving the lagoon's Location: Main river channel between Interstate 5 and the Pacific Ocean tidal prism by up to 50'. The land is presently high Salicornia marsh and (Areas Ii and XIII) and into the South Channel to the Grand Avenue Bridge. the excavations would remove approximately one acre of this vegetation. rir Actions Needed: Preparation of EIR/EIS; Section 10/404 secured. Hc.wever the land is now highly disturbed and the pickleweed is not extremely Estimated Cost: Up to $250,000, depending on level of flood protection. healthy. Especially near the airfield, where the new basin is expected oncerns: s in all lagoons and river mouths, channels of San Dieguito to be constructed, the vegetation reflects the disturbed characteristics River have been constricted by heavy sedimentation. The lagoon has of the once developed site. The increase of tidal por.ds, imudflats, also been subjected to extensive fill and physical development which and marsh channels also has value in retarding doimesticc animal has cons.tricted its flood capacity. In terms of lagoon stability, the and human access into the core area. In the middle of the channel loop sedimented channels create another constraint to adequate tidal flushing is a salt flat which would be retained and enhanced as a potential Least and water movement into the backwater areas, as noted in the discussion Tern nesting island. of the tidal prism; but because of the high expense of dredging and its Fiscal npact: Thle substantial cost for this phase should be primary flood management purpose, it has been identified for late borne by shared funding tirougih WCB and the Conservancy. Funding may be phasing (four or more years) and funding from sources more appropriate available from COFPHE, as in Phase 2. In addition, the high environ- that the Conservancy or WCB. mental values of this phase suggest that federal help from the Land and 1) Coordinate project design with the City's Jinmmy Durante Water Conrervatioi Fund would be appropriate and should be sought bridge replacement project currently under study. The by Del Mar and the Conservancy as part of developing a work program for estimated time frame for construction of the new bridge Phase One. is 1981-1982, to be financed by federal urban bridge replacement funds. 6. PHASE FIVE: Upland Habitat Enhancement 2) Seek "Small Watershed Project" funds (PL566) from the Soil Conservation Service or "Small Flood Control Project" Objectives: Increase overall habitat variety, resulting in an associated funds from the Army Corps of Engineers. increase in wildlife species diversity and productivity. _.nI Dredging will cause short-term impacts by removing Lead Agency: Department of rish and Game some benthic organisms and increasing turbidity. Benefits will include Location: All upland areas within the DFG-managed "Ecological Reserve", improval tidal flow and flood protection. A full EIR/EIS will be required including the dry areas between the south channel/fishhook area and at the time of project design. Interstate 5, as well as the sand dunes near the mouth of the river. Fiscal Impct: Costs would most likely be borne by a federal grant, matched Prior Actions Needed: Public acquisition of all areas to he enhanced by 50% local funds if it becomes a Corps project. and comp)letion of marsh enhancement in areas adjacent to the uplands, to be enhanced. Estimated Cost: Materials, equipment and labor to be donated and/or 'integrated into the management agency's program budget. Equipment: Hand tools and construction tools. Tasks: 1) Clear rubble and weeds from the upland areas. 2) Revegetate and contour the areas using native Coastal Sage Scrub species. 3) Construct a boardwalk and protective fencing from Camino del Mar around the sand dune habitat to the beach to reduce foot traffic on the dunes. B6 when drastically altered by man. San Dieguito Lagoon, like the other coastal lagoons was formed about five thousand years ago, and has proba- ~~~~~~~~~APPENDIX C ~bly changed very little during the one thousand years prior to 1900. APPENDIX C REVIEW OF THE HYDROLOGY AND TIDAL INFLUENCES There is evidence indicating that the changes in patterns of erosion REVIEW OF THE HYDROLOGY AND TIDAL INFLUENCES and sediment transport in the County have accelerated the lagoon filling IN THE SAN DIEGUITO LAGOON processes during the last one hundred years. As a result of this filling, restrictions in tidal circulation, and the discharge of wastes into the The dearth of information on many aspects of the functioning and exis- lagoon, the biological character of the lagoon has been seriously de- The dearth of information on many aspects of the functioning and exis- ting state of this lagoon preclude a definitive approach to its enhancement graded, and the natural populations have diminished both in numbers and and management. This enhancement plan must, therefore, ultimately be viewed diversity. Nevertheless, some of the lagoon habitats are still in ex- as an experimental one, wherein optimal conditions are expected from the cellent condition, and there are, in several areas, lush growths of proposed design but cannot be guaranteed. Initial improvements were design- marsh flora, and an abundance of fish and birdlife. In some respects, ed to permit continued lagoon development as funds and personnel become the channels may not have changed greatly from their 1889 configuration. available. In order to augment current knowledge of west coast estuarine Thus, wherever the lagoon channels have not actually been destroyed by availble.In oder o augent urret knwledg of est oastfilling, they have demonstrated a considerable degree of stability over and lagoon systems, monitoring of physical and biological parameters is filling, they have demonstrated a considerable degree of stability over necessary. the last fifty to one hundred years. A similar stability is evident in certain low areas which have not been developed. This procedure will also clarify the structure and function of the San Dieguito Lagoon, thus permitting its more effective management. The physical processes most likely to affect the stability of a lagoon result from fluvial and tidal flows, and the resulting erosion This appendix summarizes the consultant's report on tidal influences and sedimentation. The passage of floodwaters through the area has not and the lagoon mouth. Wendall Gayman of Sea Science Services prepared altered it greatly during the last one hundred years. However, use of this materialwhich staff has edited and augmented with an introduction, the basin and the implacement of various structures has altered the Citations and references have been excluded but can be found in the origi- watershed considerably, but there is only a limited amount of evidence nal report located at the Del Mar City Hall and the Conservancy offices. which would lead to the conclusion that such changes have drastically affected the stability of the lagoon.. Land use changes have increased This appendix addresses the following topics the percentage and rates of runoff resulting in floods with greater Present conditions; assessment of lagoon stability; benefits of an volumes and higher peak flows. However, the Lake Hodges Dam and other open marine system; oceanographic influences (tides and waves), structures have curtailed the runoff from most floods, thus reducing tidal flushing; tidal prism; achievement of natural flushing; peak flows in the lower San Dieguito River Valley. and options. Present and future developments and land uses within the basin are PRESENT CONDITIONS also expected to increase the sediment yield. However, the Lake Hodges Reservoir will trap 100 percent of the sediment from the upper 88 percent Since at least the nineteen thirties when the fairgrounds/racetrack of the basin. Thus the calculated sediment load carried by the lower was placed on fill, the lagoon mouth has been closed by sand bars except San Dieguito River below the Dam is substantially less than the load when high runoff of rain (or sewage when it was piped into the channels) that would be carried under natural (pre-dam) conditions. has scoured the entrance. ~~~~~~~has scoured the entrance. ~The erosion of about 40,000 cubic yards of sand from Crest Canyon, In addition, the construction of the California Southern Railroad and the deposition of this on a large fan built across the southern (1883-88) and the Santa Fe Railroad (1934), the Pacific Coast Highway margin of the marsh during the last two years is certainly an unstable (1912 and 1927) and Interstate 5 (1965-66), have dissected the lagoon characteristic. If similar occurrences took place in the near future, channel systems and constricted their courses to the bridge underpasses. then one could certainly conclude that the marsh area was unstable, and The construction of upstream dams at Lake Hodges and Lake Sutherland on perhaps not worthy of substantial enhancement efforts. the San Dieguito River have greatly reduced the volumen and scouring L potential of the flood waters entering the volumen and scourings. Calculations suggest that in the past, the San Dieguito River has carried sufficient sediment to fill the lagoon within a few years The heavy rains of 1977-78 apparently created enough scouring of the Either the sediment transport calculations are grossly in error, or interior lagoon to help keep the river mouth open into October, 1979. much of the sediment load has passed rith through the lagoon during However, this status is probably also a result of the reduced sand load periods of rapid runoff. The presence of large volumes of sand on the reaching the beach and the ongoing erosion of the shore as well . beach and beneath the nearshore waters has been considered evidence for Sedimentation will reduce this prism and the gain can only be viewed the latter assumption. as temporary. A closed lagoon mouth will again occur, resulting in an unstable eutrophic polluted water body. In terms of the water characteristics, the lagoon has exhibited substantial instability during recent years. The waters have ranged ASSESSMENT OF LAGOON STABILITY from very shallow, over much of the area, to several feet deep over most of the channel areas (when the lagoon remains closed, following Geologists consider coastal lagoons and estuaries to be ephemeral several periods of moderate runoff). Probably the salinity has varied features. Depressions in the coastline tend to be filled rapidly from less than two parts per thousand, during the winter to 32 to 34 (geologically speaking) with sediments transported by fluvial processes parts per thousand when the lagoon is open during the spring; salinities and littoral currents. However, in human terms, the San Diego County of 40 to 60 parts per thousand may have occurred in some portions of Coastal lagoons have been almost as stable as other environments, except the lagoon when it was closed and desiccated during the summers of the dryer years. C There are, of course, a number of organisms (particularly the Lowered circulation in a closed lagoon would likely lead to pro- water birds and marsh plants) that can readily adapt to such changes. blems with algalmat formation, eutrophication, and mosquito breeding. But the impact on fish and invertebrates are more immediate and severe. A closed entrance can also temporarily aggravate flood problems (but it will also resist high tides which can present hazards). Whenever the lagoon entrance is open sufficiently to permit sub- BENEFITS OF AN OPEN MARINE SYSTEM stantial tidal flooding, the lagoon's waters become remarkably stable with respect to temperature, salinity, and other characteristics. Seasonal flooding of the San Dieguito River would naturally lower Tidal flows do tend to carry littoral sediments into the lagoon. salinities in the lagoon waterways and temporarily reduce populations of However, it is probable that the net sedimentation inside of the lagoon aquatic organisms. Recolonization of the lagoon should follow quickly entrance that has occurred during the last fifty years is no greater through an open entrance. than the amount of sediment deposited on the Crest fan during the last two years. Although there are some natural processes that are slowly Faunal diversity and productivity in a marine lagoon should be the tending to decrease the stability of the lagoon, the greatest threat is highest of all proposed water regimes, especially with daily tidal posed by the human development of the area. But we also have the ability flushing. Foral diversity in marine lagoons is low, especially for to restore portions of the lagoon, and to increase its present stabili- macrophytes. Floral (i.e. primary) productivity is known to be very ty, with a very modest effort. The simple expansion of the tidal prism high in coastal marine wetlands. should do a great deal to restore the stability of the lagoon. A marine lagoon may benefit the least tern by harboring larger num- With no tidal waters able to enter the two lagoons, a pattern bers of small fish. An open lagoon may produce healthier or larger exists of high water salinities in the summer and low salinity in stands of Salicornia, the preferred habitat of the Belding's Savannah the winter. This pattern is the result of waters within the lagoon Sparrow. Thus, the latter species may benefit from a tidal marine system; evaporating (and concentrating the salts) during the summer, then being its food source will probably be minimally altered by an open lagoon. diluted by winter rainfall. These tremendous changes in salinity present a harsh environment for fish and wildlife. Most fish species In summary, a marine system would benefit myriad marine inverte- can not survive such physiological stress. And, severe water surface brates and fish, and possibly endangered species as well. Mosquito, changes caused by the drying up in summer of areas flooded by winter rains, prevent successful nesting by resident wildlife species depend- eutrophication and flood problems would be beneficiay affected even more if the lagoon entrance ent upon this source of ponded water. aspects would be beneficially affected even more if the lagoon entrance was kept open to continuous tidal flushing. Pollutants in the lagoon also go through the same pattern of OCEANOGRAPHIC INFLUENCES (Tides and Waves) concentration as does salinity. Influences that can improve lagoon water quality (which includes, increase of dissolved oxygen, lower temperatures, moderate salinity) The characteristi are stream flow, tidal flushing and wind action at the water surface. topography (or bathymetry) of the estuary and the dependent upon the In the San Dieguito Lagoon, all three of these forces may operate at tance of freshwater flow, and the action of waves and tides. In some time of the year, but generally lagoon entrance closure and stream-flow Southern California, where the ru noff is intermittent, and estua- cessation have still minimized water quality and aquatic faunal diversity. ries are very li mited in i ze, the wave action also plays and im- As a general rule, environmental characteristics (such as, salinity portant role in determining lagoon characteristics. The scouring water temperature and dissolved oxygen) become controlling or limiting action of entrance channel currents is constantly being countered only when they reach extremely low or high levels. However even slight by the influx of sediments deposited in the entrance channels by dissolved oxygen changes can impact some specie, in tidal marine systems. wave-induced currents. If an estuarine entrance channel is to re- The above characteristics levels tend to be moderated, largely due to the main open and stable, the ebbing tidal currents must have suffi- circulation of water at regular intervals. In stagnant or enclosed waters,t velocity an capacity to keep the channel free of sediments especially shallow waters, factor levels can become extreme, and can eposited by littoral currents. severely stress or kill squatic organisms. Attached or benthic or planktonic invertebrates are generally more vulnerable to stress conditions than mobile Ocean tides along the Southern California coast are termed organisms because they cannot escape to less stressful areas, although some mixed" because their characteristics fall midway between the semi- species can endure harsh environmental factors for some time by retracting daily tides, which occur along the Atlantic Coast of the U. S. into the mud or their shells. In enclosed water bodies such as the lagoon, (and elsewhere) and the daily tides which occur along the Gulf and particularly in those that are shallow and of relatively small area, oast. two h igh and two low tides occur off the coast of Del Mar even mobile organisms (e.g. fish) cannot escape. In these instances, the almost every day. Usually there is a strong inequality between the more tolerant species may survive but the less tolerant may die, resulting elevations of bothof the high tides that occur during a single in a lower species diversity. If conditions continue to deteriorate, most ay, and both of the low tides. organisms may ultimately die. In addition, the closed system does not permit passage of marine organisms into the lagoon, again limiting species The mean tidal ran ge along the open oean sho res of San Diego diversity. County is 3.6 feet. The average range between the mean higher high water (MHHW) and mean lower low water (MLLW).levels, which occur each day is 5.2 feet. The minimum daily range of the tides is about 1.5 - 2.5 feet, and the extreme (yearly) range of the tides is about 9.6 feet. C-2 Mean lower low water (MLLW) is the normal datum level for tidal TIDAL FLUSHING predictions and offshore hydrographic surveys. This is about 2.7 feet below mean sea level (MSL). Thus, along the open coast, the mean high Tidal flushing is important for two reasons. It maintains the high water is 1.8 feet above MSL; mean higher high water is 2.6 feet above MSL; water quality of the lagoon which in turn is responsible for the quality and extreme tidal elevations above mean MSL is about 4.9 feet above MSL. of wildlife habitats and the abundance and diversity of organisms which inhabit the lagoon. Incoming tides bring in waters of nearly uniform The range of the tides varies considerably throughout the fort- salinity, medium temperature, and high dissolved oxygen content. These nightly tidal cycle. The neap period (which means low tidal influ- incoming waters also contain an abundance of plankton and other small ence) is characterized by minimum ranges (daily neap ranges commonly organisms, and the waters are rich in nutrients. The outgoing tides vary from 2.5 to 4.0 feet in the San Diego area). The highest and remove waters from the lagoon which may be characterized by: undesir- lowest tides in the cycle occur during the spring tidal period. In ably high or low temperatures and salinities; depleted levels of dis- the San Diego area the spring tides commonly have maximum ranges of solved oxygen, plankton, and certain nutrients; and relatively high 6 to 8 feet. concentrations of suspended silt, organic matter, municipal or agri- cultural wastes, and/or other chemical pollutants. I ~ ~~~The tidal ranges within San Dieguito Lagoon differ consider- ably from those ranges occurring in the adjacent open ocean. If the Tidal flushing is also important because the ebb currents may tem- lagoon entrance is closed, then of course, there is no tidal action porarily or continuously keep the lagoon entrance channel free of at all in the lagoon. If the entrance is open, water levels within littoral deposits which would otherwise rapidly fill the entrance channel. the lagoon will tend to rise and fall, following water level eleva- tion changes in the open ocean. However, the water levels in the Rates of tidal flushing are dependent upon tidal ranges, entrance lagoon will cease to follow the water level changes in the adjacent channel cross-sectional characteristics (especially "sill" depth), and ocean whenever the open ocean water levels drop below the lagoon the area and volume of the lagoon. These rates will be lowest during entrance channel sill level. the "neap" tidal periods. High sill levels and small channel cross- sectional areas also result in reduced rates of flow. Conversely, Tidal levels in the lagoon also differ from the levels in the high rates of flushing correspond with high spring tidal ranges, low sill ocean, because of the time delay necessary for waters in the lagoon elevations, and large channel cross-sectional areas. to reach the levels in the open ocean. On a rising tide, the lagoon water levels lag behind and are thus lower than open ocean levels. Another factor of prime importance to the flushing rate is the On a falling tide, the lagoon water levels are higher than levels volume of the lagoon between the level of the highest tide, and the low- in the ocean. The delay is caused by the friction in the entrance and est tide, or the highest tide and the sill level. This volume is termed adjoining channels, and the limits (inertial effects) on flow velo- the tidal prism, although the term may be used to define the volume of cities within the lagoon. lagoon waters between any two tidal Tevels. In the technical literature, the tidal prism of larger lagoons is often defined as the volume between These factors affect both the timing and the range of the tides the MHHW and MLLW levels. The cross-sectional area of the entrance chan- within the lagoon. The highest tide within the lagoon occurs some- nel is usually assumed to be the area below mean sea level (MSL). These time after the time of the highest water in the open ocean. Al so, definitions are not useful in-describing tidal conditions in small la- high tides in the eastern end of the lagoon may occur sometime after goons, beoause the sill level may be above (MLLW) and perhaps in some the waters near the lagoon entrance have reached their highest levels. cases, even above MSL. The tidal prism between MSL and mean higher high water (MHHW may be less than half of the prism between the sill level The elevation of the highest tides within the lagoon are lower than and the highest water level. the elevation in the open ocean, and the elevation of the lagoon tides decreases with increasing distance from the lagoon entrance. The time Large tidal prisms usually result in high rates of flow and high delays and the extent of the damping of tidal ranges within San Dieguito flow velocities in entrance channel areas. These high flow rates and V Lagoon are not known. velocities are often of critical importance in keeping the channel entrances swept clean of sediments deposited by waves and wave-induced The imedely fr th ocurrnceof te hgh ide, an th exent currents. If the flow rates and velocities in any given estuary are not The time deaypn for thea ocrrances ofl thepn highsidesabl nd the extntrac sufficient to keep the entrance channel free of deposits, then the en- channel characteristics (cross-sectional area and sill level) and on ' Iranc ilb lsdb aua rcse.7 the dimensions of the various cha-nels connecting the lagoon entrance TH IDLPIMNSADEGTOAON with areas more distant from the sea. Lower sill levels, deeper channel ITDAPRSINANIEUO L G O N rn depths, and larger cross-sectional areas should produce shorter delay U periods, and reduced damping of tidal ranges. pimi a igioLgo hne alwt hne Along the Southern California coastline the lower low tide alwayTetdarsm in S nDuToLgnchanes tdalywt hne ys in the tidal range, and c hne nelevation of the sill level. Changes follows the higher high tide. Consequently, the maximum rate of tidal in the sill level have not been studied, but one may assume that this U that is is generally assumed that the maximum velocities of the ebb currents draining a tidal estuary would always exceed the maximum velo- cities occurring during period of flood tides. The maximum rates of tidal level changes occur midway between the s l e e stehgete~vto fLnsoe high and low tide slack periods. Water level change rates during the an'd cobble occuring along the axis of the lagoon entrance ' [~ six hours between the high and low slack period commonly average 1.0 channel. feet/hour and range up to 1.5 feet/hour. C- 3 entrance channel and rates ot deposition by littoral currents. ine rates of flow depend in part upon high tide levels which fluctuate cycli- cally during a fortnightly period. Ebb current flow characteristic may more rapidly, and the waters most distant from the entrance, are exchanged also be increased by freshwater flows. less often. Also, during the neap periods average rates of exchange might be reduced to once every 37 hours. Rates of littoral deposition will be dependent upon wave height, period, and direction of approach. High waves approaching the shoreline Tidal prisms for San Dieguito Lagoon have in past literature been at large angles to the normal will usually produce high rates of long- reported to be 0.2 and 0.8 million cubic feet. None of these references shore transport. have indicated what tidal levels were used in calculating the prism values. Using the 30-acre area for San Dieguito Lagoon, an increase of The determination of any given tidal prism for San Dieguito Lagoon water level of only 0.15 feet would account for the 0.2 million cubic requires certain assumptions concerning the range of the tide, and in- foot tidal prism. The 0.8 million cubic foot tidal prism would require formation on the area of the Lagoon. Since the lagoon water surface a tidal range of only 0.61 feet. Surely, these ranges are far too low, area varies with the water elevation, precise figures are not easily even for the MHW prism. determined. And averages are necessary. Information on the exact tidal range within the lagoon is presently During the three decade semidrought, the lagoon entrance was closed not available. However, during the late spring of 1979 tidal levels in most of the time. The sill level was above the highest tidal levels. the eastern half of the lagoon were observed to range from 0.5 to 1.5 During this period, the effective tidal prism was zero. During the first feet above MSL, and the highest tides (which occurred at night during six months of 19-9, the sill level appeared to be close to MSL most of this season) flooded areas as high as 4.0 feet above MSL. This suggests the time, but periodic measurements were not made of sill elevations. a maximum tidal range of 3.5 feet or more. With this assumption to identify the tidal prism, one needs merely to multiply the tidal range by the lagoon area. The banks of the lagoon are The limited historical evidence available suggests that the tidal fairly steep, especially in areas between the railroad bridge and Jimmy prism of San Dieguito Lagoon has changed greatly during the last 100 Durante Bridge. Also, there are fairly steep 2-foot banks along much years. The lagoon water area shown on the 1889 U. S. Coast and Geode- of the margins of the South Channel. Thus, below elevations of 3.5 to tic Survey map of San Dieguito Lagoon covers about 42 acres. The area 4.0 feet, the lagoon area does not change drastically with changes in of the entire marsh has been determined to be about 570 acres. The water level. Once the waters rise above 4.0 feet, large areas may be 1889 map, and the 1928 aerial photographs show entrance area to the La- flooded (on the north side of the channel between the Camino del Mar goon to be much larger than it is now. Probably the sill level was and the railroad track, and east of Jimmy Durante Bridge, south of the lower in 1889, and the natural flushing at that time was much more main channel). However, the increase in area with higher water level is like the flushing now taking place in the Tijuana Estuary. One might considerably less than occurs in some other undeveloped lagoons. assume that one hundred years ago the value of the tidal prism in San Dieguito Lagoon for any given tidal range was two to four times larger It has been determined from orthophoto maps that the lagoon has a than the present tidal prism. low water area of about 30 acres, with a sill level of 1.0 feet, then MHW and MHHW tidal prisms are 2.3 and 3.4 million cubic feet,- respec- THE ACHIEVEMENT OF "NATURAL FLUSHING" tively. The calculated tidal prism would be large with the increase in area with increasing elevation. However, the actual tidal flow for any given ocean tidal range will be less than the tidal prism volume because The term "natural flushing" may be applied to a coastal lagoon tidal ranges in the lagoon are less than in the open seas. The extreme when there is a continuous flow of tidal waters filling and draining tidal prism corresponding to a 7.3 foot tide, will be larger than 6.0 the lagoon without the need for artificial maintenance to keep the cubic feet. lagoon entrance open. Channels maintained by natural flushing are subject to the same sedimentary processes which tend to silt in or If these volumes are observed to be real, then ebb currents over plug the channels of artificially maintained lagoons. Sediments are a six hour period would average about 106 and 157 cfs for the MHW and carried into the entrance channel by littoral,tidal, and fluvial cur- MHHW prisms; peak flows may be two or three times this rate. If a rents. The sediments deposited are subsequently eroded from the chan- channel cross-sectional area of 300 square feet is assumed then there nel by high velocity ebb currents that sweep through the constricted would be an average flow velocity of about 0.35 and 0.52 feet/second, tidal entrance. The width and depth of the channel are in equili- respectively. The average discharge during a six hour interval follow- brium with the rates of deposition by various processes, and the rates ing the flooding of the lagoon by an extreme tide would be equivalent of erosion resulting from tidal flow. Thus the entrance channels may to a constant freshwater flow of about 287 cfs. remain stable for hundreds of years (without man's assistance) even though deposition within them may be more or less a continuous process. The volume of lagoon water below the sill is not known. However, Channel stability doesn't necessarily imply that the channels are the average depth may be about one to two feet. If the average depth stationary. Under compl y natural conditions the channels is assumed to be about 1.5 feet then the volume may be about 2.0 mil- nown to migrate back and fomple tely naturalon the shoreline, in re known to migrate back and forth along the shoreline, in response to slion cubic feet (45t avcre-feetlow intothelagon wth achnatural variations in the controlling processes. Using this valuet3 the average inflow into the lagoon with each Sedimentation resulting from littoral drift is the primary process tide is about 1.3 times the volume of water below the sill. On the tending to term inate natural flushing Natural flushing might be average, the water in the lagoon would be exchanged at least twice a terminated by 1) a marked increase in littoral drift, or 2) a reduction day. Actually, the lagoon waters nearer the entrance are exchanged in the tidal flow. It is recognized that the rates of littoral drift may increase markedly as the result of one or more unusually severe wave storms. However, there is no particular reason for believeing that eet -.ri.r she `ijuana estuary is reproted to have a tidal prism of 2.5 million there has been or will be any substantial change in littoral drift rates. feet. L -4 Atn reduction in tidal prism may result from both the artificial and maae for certain physical differences in the areas compared. It is Aaturactillingo thedagoon.The San Dieguito Lagoon tidal prism has believed that such methods will provide useful data but, because of the natural filling of the lagoon. The San Dieguito Lagoon tidal prism has deienesnifomtnonhr-emltoalrftaete been drastically reduced during the last one hundred years due to deficiencies in information on short-term littoral drift rates, the been drastically reduced during the last one hundred years due to artificial filling. Also the stability of the natural channel has been resulting minimum prism enlargement values should still be considered reduced by constricting it (with the construction of dikes and bridges) experimental. in such a way that it is no longer free to migrate as a result of the One course of action which one might follow in implementing tidal Unatural processes. taSaDigioLgoprblywsfuhdprism expansion would be to plan several stages of enlargement. For ex- It is believed that San Dieguito Lagoon probably was flushed ample, one might increase the tidal prism by 100,000 cubic yards, and naturally and continuously one hundred years ago, and perhaps as re- then test the results for a suitable period. If frequent closure cently as sixty years ago. The loss of natural flushing is attributed occurred, then the tidal prism might be enlarged by another 100,000 cubic to the reduction in the tidal prism. For this reason it is believed yards. If natural flushing does not work at some point where further that natural flushing can be restored to the lagoon by enlarging the prism expansion is not feasible, then it would be necessary to resort to present tidal prism. other methods. However, the increase in the tidal prism would make the operation of most other methods (i.e., those not dependent upon flow It has often been assumed that by relating the tidal prism of any lagoon to the entrance channel cross-sectional area one can determine through pipes) easier, less expensive and/or more efficient. the minimum tidal prism necessary for the maintenance of natural flush- ing in any tidal lagoon. Unfortunately, this assumption is not correct. The cst of p roviding natural flushing results primarily from the expenses incurred in increasing the tidal prism. This depends upon two The processes controlling the natural flushing of small lagoons factors, land and excavation costs. The problem of land acquisition is are complicated by several factors. First, the tidal prism is not a outside of the scope of this report. constant, but varies considerably throughout the fortnightly tidal cycle. outside of the scope of this report. Second, the entrance channel cross-sectional area varies rapidly with Excavation costs depend upon the methods and volume of excavation, the stage in tide (and probably with the rates and velocities of tidal sediment and water table characteristics, the location of disposal sites, flow). There are no widely accepted methods for determining the tidal and the elevation of the land excavated. prism in a small lagoon. Prism volumes may be measured from some ar- bitrary level (often assumed to be the sill level) upward to the mean The most cost efficient excavation would be solely limited to high water (MHW) level, the mean higher high water (MHHW) level, or to The most cost efficient excavation would be solel limited to the highest level of tidal inundation. In most San Diego County Lagoons, t he removal of sediments found within the rane of the tidal p rism Ithe sill level is unstable, and probably varies considerably in elevation elevations. The removal of sediment from below the sill level and from above the hiqhest tide level does nothino to increase the tidal orism. in response to erosive and depositional processes related to the semi- daily and fortnightly tidal cycles. Thus, the tidal prism may be diffi- However, any materials above the highest tidal levels in any excavation cult to measure with any high degree of accuracy. Of course, by making site must necessarily be removed in order to excavate the lower layers. various assumptions, one can readily derive estimates for average, maxi- lso, it may be useful to excavate below the sill level 1) in antici- mum, and minimum tidal prisms, but one might question the significance pation of lowering the sill level in the futre, 2) to allow for modest rates of sedimentation, 3) to provide basins for fish and other swimming of these values. organisms, and 4) to reduce the friction resulting from current flows. The study of natural flushing is further complicated by the fact For these reasons it appears that in some areas perhaps 2 to 3 cubic that the cross-sectional area, and entrance stability are strongly yards of material will have to be excavated for every cubic yard of affected by short-term (daily, weekly, monthly, and seasonal) drift rates, increased tidal prism. These rates are not known, and are very difficult to measure; they have not been determined, directly or indirectly for periods of lagoon reti of the plan is neare as c ibla tory characteris- closure. Available rates of littoral drift are usually based on periods tics of the lagoon, as nearly as possible and within the limits of feasi- bilit y to condi tions which are believed to have existed in the lagoon oneht of one year or more. The use of long-term drift rates in the investi- bility to conditions which are believed to have existed in the lagoon one gation of entrance channel dynamics would be somewhat analogous tocentury the lagoon was thought t gatin ofentrnce hanel dnamis wold b soewha anaogou tohave been open to the sea continuously and flushed daily by the tides. attempt.to study the occurrence of fluvial floods, if the annual rainfall ave been open to the sea continuously and flushed daily by the tides. It is not practical to reconstruct the marsh exactly as it existed in the ~was the only data availabl~e.~ ~late 1800s. However, attempts can be made to reconstruct, enlarge, or restore the tidal prism to its earlier, natural volume. Although Rates of drift determined by entrapment yield data only on the this might be done by excavating a number of narrow, winding channels, net drift i.e., the difference between the littoral drift rate to the ti ih edn yecvtn ubro arw idn hnes net drifthe difference betweenand the littoral drift rate to the south. Probably the lagoon it is more economical to dredge one or several small basins. This would I ~ ~~north, and the littoral drift rate to the south. Probably the lagoon entrance closure is more closely related to short-period littoral drift produce the same affect on circulation, although it falls somewhat short i rates in one direction (either to the north or the south) of recreating the exact habitat types that previously existed in the area. rates in one direction (either to the north or the south). The three decade semidrought also may have contributed substantially L Therefore, it is concluded that while the processes controlling the The t decadto he loc ont ribute d substantally qualita~~~~~~~~~~~~~~~~tov tese herei nufcetdt aviablt oeratione of it the lagoon durstsing reepn th yentars e supe tdly ofrun- stability for small lagoon inlets may be fairly well understood in a to the alteration of the lagoon during recent years. The supply of run- qualitative sense, there is insufficient data available to enable one into the even at the entrance open to tidal d t to determine the minimum tidal prism necessary for the maintenance of ing. In the event that the entrance is closed by littoral deposits, it to trme ftheminim t h m ryo the mainlete e should reopen naturally whenever the fresh waters within the lagoon have accumulated to such an extent that overflow over the sill occurs. It appears that the magnitude of the necessary tidal prism enlarge- ment might best be determined by: 1) studies of the area or volume of Freshwater flows during the recent dry period have been inadequate the lagoon when it was last known to be tidal, and 2) comparisons with to sufficiently cause overflow of the lagoon, and the reopening of the other small lagoons that are naturally flushing; adjustments might be entrance. The shortage of runoff has also been greatly aggravated by the presence of the Lake Hodges dam, which trapped all of the flow from the upper 87 percent of the basin for more than 30 years. C -5 Because of the factors described above, it has been concluded that the conditions observed in San Dieguito Lagoon since 1945 have been neither average or natural. The limited historic evidence available, and the example presented by the Tijuana Estuary, suggest that under natural conditions the small San Diego County lagoons are open to the sea SAN DIEGUITO LAGOON CHANNELS EXCAVATION ESTIMATES all or most of the time. If this supposition is correct, then it would follow that the maximum populations and diversities within the lagoons CHANNEL PRESENT CONFIGURATIONIPROPOSED CONFIGURATION SPOILS *(CUBIC YARDS) would occur when the entrances are continuously open to tidal flow. e WEST CHANNEL Width: 200 to 200 feet Width: Same River Mouth = 2000 cy; (Ocean to channels Juncture) Depth*; O to +4.0 feet Depth*: -4.0.feet From vry o10 to Railroad The proposed plan, based upon natural flushing,:bas been advocated Bridgea 38,500 cy; because it is believed that Bridge; 44.CO cy; From JD Bridge to River 1) it will restore natural flushing as it was believed to exist in Juncture 82.000 cy. the lagoon one hundred years ago TOTAL 2) it will, if successful, terminate the need for periodic NORTH CHANINEL Width: 100 to 200 feet Width: Same (Main river channel. juncture to Depth: 0 to +7.0 feet Depth: Unclear Quoatity tobedredgeddepends maintenance of the entrance 1-5) on flood cariyinc capacity projections. 3) it will diminish the initial inundation hazard resulting from winter flooding, and SOUll( CEHN;1'EL Width: 0 tO 1200 feet Width: 70 to 1200 feet From River juncture tO Grand winter flooding, and (Juncture to bend of "Fishhok") .Oepth* : +15 (at faa 0eth*: -1 to -4.0 Avenue Bridge = 7,700 cy; 4) it will provide higher water quality than might be achieved by deposit) to -1.5 (dredging in 70 to From Grand Avenue Bridge to any other plan not requiring the entrance to be continuously feet 100 foot wid curve of "Fishhook"1.000 Cy, anyo ~~~~~~~~~~~~~pan r~~~~~~~equiri~~~~~~ng~~ ystrip only) TOTAL = 25.700 cy. ' open "FISHHOOK" EXTENSION Width: 30 feet Width: 100 feet At curve of "Fishhook" Oe,-th*: +1.5 to +3.0 feet Deth*: -1.0 foot 26.000 cy; It is expected that the higher water quality will provide higher quality T: +. to(ass es prier reroval of fan) habitats which will accomodate more abundant and diverse biological :S; channel extension- populations. TOTAL - 73,000 �y. OPTIONS excavated froa.theSe �atas). There are a number of other ways in which the San Dieguito Lagoon entrance might be kept continuously open. Some of these include: LAGOON TIDAL BASINS E SAN DIEGUITO LAGOON TIDAL BASINS EXCAVATION ESTIMATES 1) jetty construction and periodic dredging 2) use of underground pipes (underground, underbeach, and under- BASIN SIZE NESTING ISLAND MUDFLAT SPOILS YACUB water pipes) (Pod udflat) YARDS 3) use of bulldozers and other earthmoving equipment for sill WESTTIDAL BASIN 3.5 Acres Hone Total Area 17,000 cy excavations (Railroad Triangle Area IV) 4) pumping water into the lagoon from offshore 5) use of tidal gates tORTH TIDAL BASIN 9.5 Acres 0.7 Acres 1.5 Acres 89,000 cy (6) fluidization of the channel ar "; Area IX-C) (included in total) 6) fluidization of the channel bed c.;CNELTIIN CHAitEL BETWEEN NORTH 4.4 Acres None None 14,000 Cy The first four of these are almost certainly technically feasible. How- TIDAL BASIN AN ORTH AcrCHANNEL ever they may be characterized by very high initial costs, high operation- al costs, and/or severe environmental impacts. The last two techniques -SOUTH TIDAL BASIN 15.8 Acres 3.0 Acres 5.7 Acres 184.700 cy may be less expensive, but have not been proven to be technically feasi- (fostaghi Property; Area X-C) (included in total) ble for San Dieguito Lagoon-type situations in the Southern California .TOTAL 33.2 Acres** 3.7 Acres 7.2 Acres 3 Ch;,7n (see . :C' p l us.-cy While two underground pipes are proposed within the lagoon for to be excavated) sub area connections this technique is not otherwise relied on. Only I Option #3 is suggested in the plan as an alternate or emergency technique. * n a change of the consultant's recowmendation, this Basin vas shifted north towards Grand Avenue to avoid a Freshwater Intermittent Marsh Area. However, this area is higher ground and adds Wbout 0.00 ocy. of soil to be excavated. The economic feasibility studies for the more expensive projects Channel modifications will add another 5.4 acres of new water surface to this ieount (plus tidal flats). can only be based largely on costs for similar projects that have been constructed elsewhere. For this reason, and because of the variabilities. Total Excavation 496.000 cubic yards (plus soil'from flood control dredging) in sediment transport, unknown foundation conditions (for underground pipes), and the sparsity of information on nearshore construction costs, the economic date is not precise. C-6 APPENDIX D a. "Carrying capacity" is the capability of the ecosystem to sustain an optimally balanced resource base (Clark, 1977). GENERAL GUIDELINES FOR COASTAL LAGOON MANAGEMENT b. The high productivity and capacity of wetlands to store nutrients and plant material provide stability, buffering these ecosystems against fluctuations in nutrient input (Clark, 1977). �The plant productivity and carrying capacity of coastal A. GENERAL waters are normally limited by the amount of available nitrogen (Clark, 1977). 1. Marshes are geologically transitory (i.e. forming and disappearing over a period measured in thousands of years) due to sedimentation and ultimate infilling from c. The potential of any coastal water basin to function effectively deposition of eroded soils. Watershed development vastly accelerates the process as an ecosystem--to provide ecologic benefits to mankind--is governed but human intervention can also restore wetlands to a higher level of biological by the interplay of chemical, geological, physical, and biological productivity. factors. The capability of an ecosystem to provide benefits is termed "ecological carrying capacity," that is, the amount of a. Almost all wetlands suffer some degree of sedimentation requiring recognized resource value that an ecosystem can supply to fulfill human rehabilitation or maintenance to improve water circulation. needs (e.g., shellfish, wildlife, clean water, and scenic values) (Conservation Foundation, 1977). b. Wetlands are highly effective sediment traps, more effective even than other forms of quiet water bodies. 2. "Marsh management" is basically the manipulation of water supply to ensure good circulation and flushing, to encourage the growth of desirable native plant c. Wetlands have a low-energy water motion regime in which the natural species, to control undesirable plant species, and to minimize populations of processes at work will cause the water basin to fill with sediment mosquitoes and other nuisance organisms. until an energy state is reached which supports sediment transport through the area. The system is dynamic--there is no permanent a. See also D-9 regarding water drawdowns and E-5 regarding (i.e. lasting longer than 10,000 years) way to preserve low-energy deep ponds for duck usage, etc. environments. (U. S. Army Corps of Engineers, 1976). b. The elevation of water relative to land, the range of tidal 2. Coastal lagoon areas with restricted freshwater supplies are suited for marine fluctuations, and the force of tidal change are the keys to and intertidal habitat maintenance, due to the natural history and the "coast-al restoration (U. S. Army Corps of Engineers, 1976). dependency" of these habitat types. �However the proximity of freshwater habitat near salt marshes is . c. Periodic monitoring of marsh water level, rainfall, streamflow, highly desirable (see E-l). vegetation, sediment volume, and inflow are required or useful for efficient water management (County of San Diego, 1976). 3. Each marsh has its own specific ecology, problems, and personality, but there are common features and management techniques for marshes. However, management 3. Defining the outer edges of a marsh can be difficult but is essential to a techniques and principles have been poorly documented in formats usable by local management program--the area of application of laws and zoning must be known and planners, citizens, and political decision-makers. the establishment of a buffer (see Section F) is based on the marsh boundary. a. "The marshes of San Francisco Bay have both unique characteristics a. The use of indicator plant species is the most effective way to define of their own and general characteristics they share with marshes the approximate marsh edges. The point where the abundance or density throughout the world." (Harvey, et. al., 1977) of upland indicator plants is greater than that of wetland indicator species is the approximate edge of the marsh. Soils are also an indicator. b. "Brackish to freshwater marshes of North America are.floristically quite similar .,," (U. S. Army Corps of Engineers, 1976) b. In California salt marshes, Salicornia usually extends to the c. "There is definite need for.. a publication (on wetlands restoration in California) but no one has ever found the time to put it together. c. The lower littoral zone of "a marsh...extends from the edge of . A d Even though much of the material that is needed for these guidelines has of the sea to elevated areas and consists of zones of vegetation never been published, it is available in one form or another." which are made up of: plants that are rooted in and adapted to (Hunt, DFG, pers. comm., 1978). water surface at mean high water; soils and plants that are subject to tidal activity at some time during the day." (Army Corps of Engineers, B. MARSH MANAGEMENT 1976) 1. The goal of all wetland management efforts is the maintenance of the carrjying capacity of coastal ecosystems at the optimum level. (Clark, 1977) * 0.~~~~~~~~~ d. "There is a gradation in plant species from the lowest 0. MANAGEMENT elevation of the wetlands up the slope to the upper boundary of the wetlands. It is relatively easy to find the point above 1. The single most important element of marsh management is water supply--either which there is no significant growth of salt-water-tolerant plants, fresh water supplies or assurance of full tidal flushing. (County of San Diego, where the floodlands begin. This will be the upper boundary of the 1976) saltwater wetlands, and will approximate the annual high water mark-- the point of the highest expected yearly storm surge." (Conservation 2. The patterns of water circulation govern the productivity and carrying capacity Foundation, 1977) of a wetland (Clark, 1977) C. LAGOON STABILITY a. Other things being equal, a flowing system is much more productive than a standing water system. 1. Development of a stable lagoon, with adequate tidal prism and flushing, will create an ecologically beneficial open marine environment. b. Inundation of marshes by tide and/or storm runoff is important because nutrients carried by the water and the detritus produced by a. An open lagoon mouth permits access to the interior by the marsh can be exchanged. (U. S. Army Corps of Engineers, 1976). marine species. c. The ebb and flood of the tide continuously provides food, nutrients, b. Maintenance of an open marine environment reduces biological stress and oxygen to the biomass; and wa ste provides are simultaneously and enables marine organisms to survive, thereby supporting a diversity removed or assimilated into the estuarine ecosystem. of life forms. d. Shallow marsh areas are highly productive but they may c. A stable salt water regime supports the growth of Salicornia species, have mosquito problems (see D-ll) unless the water is flowing. which have wildlife value and resist high marsh erosion. e. Marshes must receive a water flushing action to remove pollutant d. Stability is a result of regular, vigorous tidal flushing, which buildup and stagnancy.(Cal Poly, 1977) (Arcata, 1979) removes sand and sediment build-up, maintains the open marine environment, and facilitates flood passage. f. Construction of channels can increase flow and flushing. e. A stable, well-flushed marine environment is less likely to suffer 3. The tidal prism of a salt marsh must be adequate to secure a cleansing action. mosquito problems than an environment with poor water circulation. a. "Tidal prism" is the volume of water which is exchanged in a given 2. Because of state-of-the-art deficiencies in determining minimum tidal prism area by one tidal movement. needs, the success of atttaining a self-maintaining open-lagoon condition through human alterations cannot be guaranteed. b. The size of the tidal prism is more strongly dependent on the a. However if initial modifications are not completely successful in the enclosure, since the tidal action is strongest across the water in the enclosure, since the tidal action is strongest across the water in producing a continuously tidal lagoon, it is quite likely that bod rather than through it (Cal Poly, 1977). they will facilitate the maintenance of the lagoon entrance with reduced effort. 4. The control of the water level in the marsh will allow colonization of favored plant species, elimination of some undesirable weed species or excessive growth b. The success of creating a self-maintaining entrance may depend of others, and easy access to mosquito breeding areas for control (County of somewhat on climatic factors (rainfall, runoff, sea storms) which San Diego, 1976). are highly variable. 5. Maintenance of natural salinity patterns is conducive to maximizing carrying c. There are no widely accepted methods for determining tidal prism capacity and productivity. Clark, 1977F in a small lagoon. a. The functioning of the coastal water system is influenced by 3. Without an open lagoon mouth or high runoff rates, the lagoon may become hyper- the intermixture of fresh and salt water and the resulting salinity, saline and eutrophic. Most marine organisms would die under these conditions. which controls the types of species and their abundance. (Clark, 1977) 4. Unstable conditions (in water volume, water level, salinity, and temperature) b. Freshwater flow in an estuary or coastal lagoon dilutes salt water produced by alternation between salt and fresh water states will not make much and fosters an especially rich and varied biota, deters oceanic difference to a wide variety of bird species which use the wetlands, but will have predators, and can create a two-layer beneficial flow (Clark, 1977) a strong adverse effect upon freshwater and marine fishes and marine invertebrates. called a "salt wedge" or "tidal wedge. D-2 c. The mixing of waters of different salinities produces a sort b. The elimination or reduction of fluctuation of pond water levels, of nutrient trap. Valuable nutrients are not swept out to the ocean to hold vegetation to the edge, facilitate use of mosquitofish, and but flow with the tide among living organisms, the water, and bottom minimize water impoundments that could function as breeding sites. sediments. The ebb and flood of the tide continuously provides food, (County of San Diego, 1976) nutrients, and oxygen to the biomass; and waste products are simultaneousl removed or assimilated. c. Drainage to remove standing water, d. The natural volume, rate, and seasonal pattern of freshwater inflow d. In some cases, flattening the bottom of the pond to remove hummocks can upset the seasonal pattern and normal salinity range. (Clark, 1977) can breed. 6. Wetlands purify and regularize the flow of land runoff into coastal waters e. Vigorous flushing by tide and/or runoff. (Clark, 1977; Arcata, 1979) 12. Densely vegetated wetland areas are enhanced by increasing water surface by a. "Based on studies conducted by Cardon, et. al. (1976), it appears such means as blasting or bulldozing pothoes o r creating basins or channels. that significant amounts of nitrogen can be removed from wastewaters Nesting islands in the center of these areas are desirable. in marsh areas." (Jones and Stokes, 1977) b. "As a rule, discharge or release of pollutants into the wetlands 13 Rehabiltation work to imrove water circulation etc., all require site alte should be prevented. However, there may be some capacity for the through dredging, bulldozing, dragline operation, etc., all of which create function as a 'land treatment' system. Any such pollutants should obtain. not exceed the calculated receiving capacity of the system and should a. The disposal of dredge spoils can be the most difficult phase of not degrade surface water or groundwater below allowable standards." the o peration. (Conservation Foundation, 1977) I 7. Ample supplies of dissolved oxygen are required for efficient ecosystem function Land placement of spoils is favored over ocean disposal, and maximum carrying capacity (federal guidelines recommend a minimum of 6 ppm of 8. A naturally balanced temperature regime provides for optimum ecosystem function. spoils is often the preferred option from a time and cost viewpoint. (The use of suction dredgers can create more spoils than necessary 9. Water drawdowns can be a beneficial management tool. Seasonal (or intermittent) for most wetlands work. marshes are often more productive than permanent marshes. �Excavated soil can often be used for construction of nesting new shoot to row when thewaterisreturnedislands, levees in the flood fringe area, and elevated use areas a. In marshes managed for waterfowl production, drying removes nuisance whe re appropria te. vegetation and permits new shoots to grow when the water is returned where appropriate. (new growth provides food to wildlife); promotes growth of the desirable b. The "swamp cat" (low-ground pressure tracked vehicle) variety of annual plants; and controls undesirable emergents. (Jones and Stokes, 1978 a caterpillar tractor offers the greatest flexibility in lagoon b. In controlled salt water marshes, a water drawdown or natural mouth work and wet or een submerged land movement. Public owenhance wetland of evaporation is desirable to expose mudflats for shorebird nesting. such vehicles is desirable for public projects to enhance wetlands. (County of San Diego, 1976) c. A topographic map, preferably at one-foot contours, is necessary 10. Vegetation management is a function of water management. Mm equito control elevations is necessary to determine how the work will affect the is a function of water and vegetation management. movement of flood waters and also will indicate the most promising areas 11. Mosquito management requires: for excavation of channels or ponds. d. Tidal basins are important in lagoons with a high degree of sedimentation a. A water depth of at least four feet in any permanent ponds (County of or land filling, to increase water surface, tidal flushing, tidal prism, San Diego, 1976), to hinder mosquito breeding and support populations and water bird resting/feeding areas. of mosquitofish. and water bird resting/feeding areas. D-3 f1 b. The development of nesting islands from dredging spoils and the �The amount of water surface is the key factor in increasing construction of channels around the periphery of the management tidal prism, with depth of water secondary in importance (see -3). area can retard human and pet access. OAny improvement in tidal surfaces will increase the chances u4. Wildlife habitat in marshes is dependent, above all else, on a constant water for maintaining an open lagoon mouth and reduce the work/ investments necessary to keep the lagoon open. 5. Oen water is an important habitat. Open deep ponds are necessary to support duck E. WILDLIFE HABITAT AND VEGETATION ENHANCEMENT usage as well as to retard undesirable vegetation intrusion (and to control mosquitoes). 1. Ecotones (transition areas between different ecological communities) support a and, if there is togation or unav e mpacts, the new habtat mst be high abundance and diversity of life. (This property of ecotones is sometimes e i at the n aa s e called the "edge effect".) in place in equal or greater quantity before th e original area is damaged. a. ' . .regarding the significance of fresh and brackish marshes--where 7. Salicornia vegetation is important to birds because it provides some resting a. "...regarding the significance of fresh and brackish marshes--where and and supports insect Populations. It also retards soil erosion they interface with salt marshes...the ecological significance of such and co n tributes to detritus production. wetlands is very important. It is axiomatic that diverse habitats and contributes to detritus production. produce diverse wildlife resources and there is a quantitative factor 8. Cattails occur in freshwater to brackish marshes and also." (Browning, DFG, pers. co., 1978)and habitat value, can become overabundant an d harmful to marsh species ding vers ity.ome fo b. "...it is a familiar principle for ecologists that intermixed areas with overlaps of ecological types are more productive and support a greater a. Cattail overabundance and its matting effect can reduce waterfowl diversity of species than any 'pure' habitat." (Heath, 1966) a nd shoreb ird habitat, as well as reduce human accesS for mosquito c. "An ecotone combines the characteristics of the two communities it separates and often has an unusually high abundance and diversity of b. Cattail growth can be reduced by maintaining a constant deep water life.. .(and) thus serves a uniquely beneficial function..." (Clark, 1977) level, which is more desirable than burning, draglining, or bulldozing. I 9. Planting of desirable marsh plant species (revegetation) is sometimes desirable, 2. The concept of habitat diversity includes, but goes beyond the "ecotne"Concept, but may not always be successful (e.g., San Francisco Bay cases), and revegetation to include multiple physical variations within a habitat area: may better be left to natural succession. a. Birds. The greater the interfacing of different habitat types and structures, the greater the expected avian species diversity. Birds a. In preparing a site, the area available for planting can be respond to habitat structure variability afforded by vertical structures increased by making the slope as gentle as practicable without the (trees, bushes, poles), islands, small embayments in sides of channels pOnding of water. The gentler the slope, the larger will be the or ponds, different size ponds and depths, variable soil types, and alternately flooded and drained areas." (Clark, 1977) multiple land configurations. b. Native plants are the more desirable unless it can be shown that b. Aquatic invertebrates. Marine organisms favor different bottom an exotic species will produce desired results and will not take over sediment compositions and a variety of "structural elements" (large rocks, from nor fill the niche occupied by a native species (Harvey, et. al., 1977). cobbles, pilings, water current changes, vegetation, etc.). F. BUFFERS c. Fish. Fish benefit from different water currents, varying depths, 1 Marsh d dfat widife require protection from cose is and a variety of bottom cover (sand, rock, cobble, kelp, eelgrass, etc.). humians. (mdrone Associates, 1978) d. Species diversity fails to increase with habitat diversity when 2. A and buffer excessive habitat variability creates only small patches of usable pA land buffer b etween a marsh and human uses will add security and, with areas. pantings 3. Most wetland species cannot tolerate disturbances from adjacent urbanization and a. Deed restrictions should be recorded to assure continued maintenance must be buffered from impacts (see Section F). But there are variations in degrees of buffer areas. (City of San Rafael, 1978) of sensitivity among various species. a.of sensitivity among various species. ccessbypeopleanddomesticanib. Buffer zone landscaping can enhance the ecotone effect (see E-l). a. Unrestricted access by people and domestic animals is extremely harmful to wetland wildlife. Access should be restrained by fencing c. Wooded areas near wetlands contribute to a balanced wildlife (which for esthetic purposes should be of "naturalistic" materials, community, for example providing potential nesting areas for egrets and color, and texture) or other barriers. I D-4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ b. Upland farm layout should minimize alteration of natural drainage and prevent water pollution. (Clark, 1977) 3. Cropland near wetlands in some areas can furnish foods for upland game birds and prevent water pollution. (Clark, 1977) and -otfie-ldlife (but see G-6 regarding farm pollution). 7. Paved surfaces collect and channelize a broad variety of pollutants which are a and tewmajor source of water quality problems. (EPA, any 208 document) 4. Control of noxious weeds may be necessary for agricultural use, but some local wildlife. But the marsh purification processes can in fact be used to clean up such "nonpoint runoff" before it reaches streams (see D-6). Storm 5. Buffer areas adequate to protect wetlands will vary in width according to the drains can deliver to the marsh quantities of water not appropriated to adjacent land and soil conditions and the development uses, local zoning, and density other uses. However stormwater inflow into marshes should be tested of human and pet populations in the vicinity. for heavy metals and other pollutants which cannot be assimilated 6. Buffers are more defensible legally when they include flood and other hazard areas, and are at least partially conditioned on protecting the public health, safety, and 8. Uplands around marshes may require seeding and planting to develop a permanent welfare (see G-2-e). vegetation and grass cover, to provide uplands nesting cover, and to prevent wind and water erosion with resulting deposition in the wetlands. G. WATERSHED MANAGEMENT 1. Control of erosion and the resulting sedimentation in streams, wetlands, and water basins is a primary goal of watershed management. REFERENCES �Reduction of the speed of runoff water is a primary method to This outline of guidelines was prepared by Conservancy staff member, protect soil from erosion. Bruce E. Jones. Unsourced statements are based on input and lessons Incprotectas sedoilmentati from careless construction 3ractices seriou llearned during the planning period, with extensive reliance on the 2. Increased sedimentation from careless construction practices seriously damages streams. consultant's report,(see Gayman, below). The other references used ae: C on can increase soil erosion by removing vegetation which stabilizes soil leaving large expanses of bare land exposed to wind and running water. The amount of , , sediment eroded from areas undergoing urban development can be far greater than from :... sediiotn er ded from lard seas Urand itj ncann dpreoduc~e 20 to 200 times as much sediment California Poytechnic University, Pomona, San Dieguito Laqoon Management Activities, 1976.. as farmland does. a. In site preparation, barren soils should be rapidly stabilized . Clark, John. Coastal Ecosystems. The Conservation Foundation and John Wiley a. n s.ite preparation, barren soils should be rapidly stabilized and Sons, 1977. through revegetation and sediment should be detained on-site. b. Grades should be designed to direct flows along natural drainage Conservation Foundation, Development in Floodplains, 1977. courses and through patural terrain where the vegetation can cleanse . Council on Environmental Quality, Our Nations Wetlands, 1978. and filter runoff waters. d . Council of Environmental Quality, Report on Channel Modifications, Volume I, 1973. c. Paved surfaces should cover a minimal area to allow rapid and sufficient water infiltration into the soil. . County of San Diego Department of Sanitation and Flood Control and The Smith/Williams Group. San Elijo Lagoon East Basin Water Management Plan, 1976. d. Significant amounts of land may be required for buffer strips, runoff detention areas, groundwater recharge areas, and other water Gayman, Wendall; Steve Montgomery, Mitchell Beauchamp. Report on Environmental protection measures. However, creative use of such areas or recreation, Baseline Studies For The San Dieguito Lagoon Enhancement Plans, October, 1979. decorative purposes, or privacy screens will permit uses of high benefit to the owners. (Conservation Foundation, 1977) . Harvey, H. T., H. L. Mason, R. Gill, T. W. Wooster. The Marshes of San Francisco 3. The use of sedimentation basins directly upstream from lagoons is probably not Bay: Their Attributes and Values. A Report to the San Francisco Bay Conservation economically feasible in larger drainage basins. 4. "The higher the degree of development, the greater the need to provide vegetative . Heath, Dr. James P., "New and Improved Marshes," addendum to BCDC report on buffers along drainageways." (Clark, 1977) Riparian vegetation not only provides a Marshes and Mudflats, 1966. highly vital and diverse wildlife habitat but acts to retard one of the greatest sources of erosion -- that from streambanks--and also filters overland flow. . Jones and Stokes, Utilizino Aaricultural Drainaqe for Marsh Management, 1977. Madrone Associates. Preliminary Biological Assessment of the Triangle Marsh, 5. Nonstructural flood control measures are generally more desirable than structural Corte Madera, June 1978. measures in the watershed. (Clark, 1977) _______measures in the watershed. City of San Rafael, Staff Report on Seastrand Subdivision, San Rafael, March 28, 1978. 6. Farm operations and cropland erosion in the watershed must be well managed to protect coastal ecosystems from damage by fertilizers, biocides, sedimentation, . U. S. Army Corps of Engineer's, Vicksburg, Miss. Relevant Criteria for Marsh- and altered runoff. (Clark, 1977) Island Site Selection and their Application, 1976. a. Croplands and rangelands should be set back from watercourses to provide a vegetated buffer area. (Clark, 1977) D-5 GLOSSARY A ABATEMENT - Reduction of amount or intensity of a public nuisance, hazard, or pollution. ACRE FOOT- The volume of water necessary to cover an area of one acre to a depth of one foot (43,560 cubic feet; 32W515 gallons). AERATION - The process of being supplied or impregnated with air. Aeration is used in waste water treatment to speed up biological I ~ ~~~and chemical purification. AGRICULTURAL LAND - Land which is used permanently or during alternating seasons for production of food or fiber (includes grazing lands). PRIME AGRICULTURAL LAND - Land of high suitability for agriculture, according to the SCS and Stonie systems for evaluating I ~ ~~~farmability and soil quality. ALLUVIUM - Particles of organic and inorganic matter deposited by stream action. ALLUVIAL FAN - An assemblage of sediments (clay, silt, sand, gravel, or detrital material) deposited where flowing water moves I ~ ~~~from a steeper to a more gentle gradient and suddenly loses much of its transporting power. AQUACULTURE - The controlled production of organisms in aquatic systems. 3 ~~~~~~~~~~~~~~~~~~~~~~~~~B BENTHOS - A collective term describing bottom organisms attached or resting on or in the sediments at the bottom of a water body. BERM - An earthen shelf or ledge on a levee; or landscaped earth barrier, often used for separating and -buffering incompatible I ~ ~~~land uses. BIOTA -The animal and plant life of a region. See FLORA and FAUNA. BUFFER -A land area used to separate conflicting or incompatible land uses. See BERM. C CARRYING CAPACITY - The maximum population or biomass of a species or intensity of use that any particular area can support over an I ~ ~~~extended period of time without undergoing deterioration. CRITICAL HABITAT - An area found by the U.S. Fish and Wildlife Service to be indispensable to the survival of an endangered species. * 0~~~~~~~~~~~~~~~~~~~~~~~~ DETRITUS - Organic debrisL DISSOLVED OXYGEN - Oxygen dissolved in water. The minimum concentration necessary for survival of many forms of marine life is 4.5AM I ~ ~~~ppm (parts per million). ' DRAGLINE - A machine mounted bucket scoop which reaches into an excavation area, drags soil back until full, and then deposits lo its contents nearby.0 I ~~~~DREDGER - Boat which is used to excavate soil from water areas through a suction pipe. 3 ~~~~ECOLOGICAL RESERVE - As defined in Sections 1580-1584, Fish and Game Code, "areas preserved in a natural condition for the benefit0 of the general public to observe native flora and fauna and for scientific study". EIR/EIS - Environmental Impact Report, from the California Environmental Quality Act (CEQA), 1970; Environmental Impact Statement I ~ ~~~from the National Environmental Policy Act (NEPA), 1969. See also "focused EIR", "impacts", and "negative declaration". EFFLUENT - A waste or pollution discharge from a specific source. ENDANGERED SPECIES - A species of animal or plant is considered to be endangered when its prospects for survival and reproductionI are in immiediate jeopardy from one or more causes, such as: mortality rate consistently exceeds the birth rate; the species is incapable of adapting to environmental change; habitat is threatened by destruction or serious disturbance; survival is threatened by the unwanted introduction of other species.,through predation, competition, or disease; pollution threatens survival. The five endangered species found in California coastal wetlands are: California Least Tern; Beldingi's Savannah Sparrow; Clapper Rail;I Salt Marsh Harvest Mouse; and Morro Bay Kangaroo Rat. ENVIRONMENT - The combination of all external influences and conditions affecting life, development and ultimate survival of an organism including human beings. EROSION - The wearing away of the land surface by running water, wind or ice. ESTUARY - The meeting place of sea and river water; the area in which seawater and freshwater have mutual influence. F FAUNA - Animal life. See also FLORA. FEDERAL FLOOD DISASTER PROTECTION ACT OF 1973 (PL 93-234). Refinement of the Federal Flood Insurance Act which creates strong fiscal incentives encouraging developers and local governments to keep homes out of flood risk (flood prone) areas, or at least build them above the 100-year flood level. FLOOD, ONE HUNDRED YEAR - A flood having an average frequency of occurrence in the order of once in 100 years with a I percent probability that it will occur in any given year (also known as the "Intermediate regional flood"). FLOOD PLAIN - The relatively flat area of lowlands adjoining a river, stream, watercourse, ocean, or lake, which has been or maybe covered by water. FLOODWAY - The high velocity flow channel and high hazard portion of a flood plain. FLORA -Plant life. See FAUNA. FLYWAY -A vast region with migratory bird breeding grounds and wintering grounds connected with aach other bya systemof migrationI routes. FOCUSED~ EIR - An informal term for an EIR which is concise, is cross-referenceito existing documents, and addresses only signi ficar3 FOOD CHAIN - A series of plant or animal species in a community, each of which is related to the next as a source of food. GROUNDWATER TABLE - Fluctuating level of groundwater within the earth; high during rainy season, low during dry season. L. HABITAT, WILDLIFE - Vegetation or land formation which provides fauna with protective cover for nests, dens, mating, feeding, etc. IMPACT, ADVERSE - Damage done to a physical, social or economic situation by a program or project. The ElR/ElS process emphasizes "significant adverse impacts". See also EIR and FOCUSED EIR L LAGOON - A narrow inlet connected to the sea, that extends inland and often has some freshwater entering it, but not to the degree 0 LEVEE - A human made embankment to prevent flooding.3 I~~~~~~~~~~~~~~~~~~~~~~ MARSH - Periodically wet or continually flooded area with the surface not deeply submerged. Covered dominantly with reeds, cattails, and other hydrophytic plants. Essential habitat for migratory waterfowl, many bird species and mammals. See WETLANDS. MITIGATION - Actions taken which reduce or compensate for a project's adverse impact on a physical, social, or economic situation. MASTER ENVIRONMENTAL ASSESSMENT - An EIR-related compilation of data about an area. N NPDES - National Pollution Discharge Elimination System. As defined in the Clean Water Act. 3 ~~~~NEGATIVE DECLARATION - A brief assessment allowed under CEQA which finds that a proposed project will not harm the environment. O,P I ~ ~~~PICKLEWEED -Common name for SaiQornia, a coastal marsh plant which is a primary indicator of a saltwater wetland. POLLUTANT -Any introduced gas, liquid or solid that diminishes the suitability of a resource for a specific purpose. 3 ~~~~POLLUTION -The condition of any system being unable to cleanse itself. PUBLIC TRUST - A principle of law originating in English conmion law which establishes an easement in the public interest over the water of the state up to the high water mark. 3~~~~~~~~~~~~~~~~~~~~~~~~~~~ RAPTOR - Bird of prey; a meat-eater. I ~~~~RARE SPECIES - A species of flora or fauna is rare when any of the following occur: the species is confined to a relatively small and specialized habitat, and incapable of adapting to different environmental conditions; even if found in other parts of the world, it is nowhere abundant; the species is so limited that any appreciable reduction in range, numbers or habitat would cause it to become endangered; if current management and protection programs were diminished in any degree, it would become endangered. See also ENDANGERED SPECIES. RIPARIAN VEGETATION AND HABITAT - The narrow strip of vegetation that receives its water supply at or near the capillary fringe of tenatural water table. Typical species include willow, cottonwood, alder, wild grape. Provides invaluable wildlife cover. 3 ~~~~ROOKERY -Breeding ground or colony for gregarious birds and mammals. RUNOFF - That portion of rain or snow which does not percolate into the ground and is discharged into streams. I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~S SECTION 10 and 404 PERMITS - Permits controlling navigational intrusions and landfill in waterways required by Section 10 of the Rivers and Harbors Act of 1899, and Section 404 of the Federal Water Pollution Control Act Amendments of 1972 (now known as the Clean Water Act), and implemented by the Army Corps of Engineers. I ~~~~SEDIMENTATION - Deposit of small particles carried by water. STORIE INDEX - A rating of soils denoting their ability to raise crops;based on profile, texture, slope, and modifying features J without consideration of agricultural practices to increase soil suitability. 0 I ~ ~~~SWAMP CAT - Popular name for a low-ground-pressure form of bulldozer, having very wide tracks which allow it to move over wet ground. W TDS - Total Dissolved Solids. Refers to minerals, usually salt, in water. TID-- The alternative rising and falling of the surface of all water bodies, especially those connected with ocean, caused by the gravitational pull of the sun and moon occurring unequally on different parts of the earth. TIDE LANDS - The portion of the ocean shore which is covered and uncovered by the ebb and flow of the tides. TIDAL DELINEATIONS: MEAN HIGH WATER - The mean height of tidal high waters at a particular station for 18.6 years (usually synonymous with mean high tide); MEAN LOW WATER - The average height of the low waters over a 19-year period; MEAN SEA LEVEL - The average height of the surface of the sea for all stages of the tide over a 19-year period; MEAN TIDE LEVEL - The tidal plane halfway between mean high water and mean low water, synonymous with half tide level; ORDINARY HIGH WATER MARK - Boundary line between public-owned wetlands and privately owned uplands in or along waterways not under influence of tides. TOPOGRAPHY - Configuration of a surface including its relief and position of natural and man-made features. TURBIDITY - Condition of water which is thick with roiled sediment. U,VW,X,Y,Z VECTOR - Any species which can create health or safety problems (e.g., rats and mosquitoes). WETLANDS - Areas that are inundated or saturated by surface or ground water with a frequency sufficient to support a prevalence of plant or animal life adapted to saturated soil conditions. SELECTED REFERENCES o California Polytechnic University. Coastal Design Group. San Dieguito Laqoon: A report on management alternatives to the City of Del Mar, 1977. o Council on Environmental Quality, Our Nation's Wetlands, 1978 o Department of Fish and Game. Coastal Wetlands Series (20 reports). o Gayman, Wendall, Mitchell Beauchamp, and Steve Montgomery. Environmental Baseline Studies for the San Diequito Lagoon Enhancement Plan. Sea Science Service and Pacific Southwest Biological Services, 1979. NOTE: This is the consultants' report supporting the lagoon enhancement program. (It cites 80 references) o Jurek, R.M. California Least Tern Recover~yPlan. California Department of Fish and Game, 1977. o TerraScan. Arcata Marsh Enhancement Plan and Draft Environmental Impact Report. .Phase II. Arcata Marsh Enhancement Project. A Prepared for California Coastal Conservancy and City of Arcata. April 30, 1979. 02. AnIL- urn ~~iu7~~ ~ pprposed' project DI~JfJ~flflflo#' ('~u~aSub-Area Reference Code auaflr~~lrl~~lnn~uD For use in locating ground UuUII~~jjJ~lj~jJ[J areas when referred to in the I ~~~~~~~~~~~~~~~~~~~~text of the plan., I ~~~~~~~~~~~~~~~~~~~VII. - A . xv Freshwater Marsh IX-A 3 ~ ~ ~~~~~~~~~~~~~~a Basin U~~~~~~~~~~~~~~~- *~~~~~~~~~~~~~~~~~~~Wne Marshoo X-~~~~~~C,. Z * Sa dieuitolagoon enhancement plan CRYof alMar. California *Stale Coastal Conservancy