San Mateo Lagoon

GENERAL			Source
Site	San Mateo Lagoon
Map	San Clemente USGS 7.5' quadrangle
Location	The San Mateo Lagoon is located within San Onofre State Beach, just south of the San Diego/Orange County border. Much of the biological data refers to the lower 1.3 miles of the creek and adjacent open space.
Contacts	State Department of Parks and Recreation, Orange Coast District (714) 848-1566 or (714) 492-0802.
	U.S. Marine Corps Base, Camp Pendleton, (619) 725-4512, 4524.
Approximate Wetland Acreage	153		1
Approximate Historic Acreage	Not specified		2,1

Ownership in acres	Owner	Acres
	US Marine Corps Camp Pendleton (The lagoon and lower San Mateo Creek are leased to the State Department of Parks and Recreation)	325	16, 6, 7

LAND USE			Source
Land Use Designation	Camp Pendleton is designated military base in the County's General Plan and Zoning Ordinance. The lagoon is within a Wetland Preserve area of San Onofre State Park.		12, 8
Onsite Use	The lagoon and portions of the creek and adjacent areas are part of San Onofre State Beach; the lagoon is in the Trestles Natural Reserve; while hiking is permitted, there are no trails; hunting and collecting are prohibited. Campgrounds are sited out of the riparian areas. Both the railroad and Highway 5 cross the marsh and/or riparian areas.		7, 2, 8
Historic Use	The railroad trestle and embankment were built across the lagoon early in the century; during construction of old Hwy 1 in the 1930's, a leveed channel was cut from the Hwy to the ocean.		16
Near Use	West of I-5 - immediately south of the lagoon is parkland, including a parking area; to the north is a U. S. Coast Guard installation of a few buildings. East of I-5 - areas south of the creek are leased for agriculture, to the north is open space,		8, 2, 14, 17
	and residential development outside the Base. There is a series of sewage treatment ponds upstream on the south side of the creek.
Historic Near Use	The Marine Corps Base was established in 1942; prior to that surrounding lands were used for cattle ranching and crop production.		14, 4

HYDROLOGY			Source
Tidal Influence	The lagoon is described as usually being cut off from the ocean by a barrier beach that forms at the mouth of the Creek; the berm is typically breached by heavy winter rains and may remain open for several months.		2, 13, 15
Watershed Area	132 square miles		13

Tributaries and Flow	Tributary	Flow	Source
	San Mateo Creek	Flows described as exhibiting wide annual and seasonal variation typical of the region, maximum normal discharge for 1966-67 was 2,760 cfs. Except during winter high flows, the stream bed upstream of I-5 is dry; downstream, flows have been year-round in	2, 13, 16
		recent years. The channel meanders across a flat sandy floodplain near the mouth; the deepest portion in October, November 1993 was 6 inches (15cm).
Dams	None identified		13
Other Sources	Groundwater		11

WATER QUALITY			Source
General	San Mateo Creek Mouth is not listed as an impaired water body by the Regional Water Quality Control Board. Beneficial uses are rec1, rec2, biol, wild, rare, mar and migr.		2, 3
Dissolved Oxygen (DO)	1985 - 1987 - 4 samples taken over the period with the 4 seasons represented, at 5 stations covering the creek and lagoon. Morning surface concentrations ranged from 5.0 to 7.1. Temperatures ranged 17.1 to 24.5 C.		16
Water Salinity	1985 - 1987 - 4 samples taken over the period with the 4 seasons represented, at 5 stations covering the creek and lagoon; surface and bottom readings were consistently 0 ppm. The same was found in October, November 1993.		16, 2
Sediment	Cultivation and development in upper watershed over the past 200 years have resulted in silt accumulation in the lagoon; some flushing occurs during winter flooding. No quantification provided.		13, 15

Soil
Soil	Lagoon bottom is firm to soft sand; soils of the creek floodplain provide prime agricultural land.		2,13

Habitat	Acres	Vegetation
Open water	6.2	1988 - species included: beakfruit sea-tassle, white watercress, horned pondweed, water pimpernel, fennel-leaf pondweed, and lesser duckweed. 1993 - approximately 50% of the creek surface was choked with watercress.	Ac., 16 Plants, 16, 2
Coastal Brackish/fresh water marsh	25 +	1988 - freshwater marsh dominated by cattail, Ca. bulrush and Olney's bulrush in nearly pure stands; brackish communities by fleshy jaumea, yerba mansa, and Mexican rush; also coyote bush, mule-fat, glasswort, salt grass and sea fig.	16
Riparian	121	1988 - Willow woodland dominated by arroyo willow; sycamore/cottonwood woodland dominated by western cottonwood and Ca sycamore; coyote bush scrub dominated by coyote bush.	16

ANIMAL USE			Source
Birds	150 species observed during weekly surveys, August 1985 - June 1986; 67 water-associated, 7 of those special status; 5 additional upland species of special status.		16
Fish	3 sampling days 1985 - 1986 by electrofishing and minnow seine found green sunfish, mosquitofish and staghorn sculpin. 1993 - survey using a minnow seine and snorkel collected mosquitofish* and tidewater gobies+; California killifish were also seen.		16, 2
Benthic Invertebrates	1985 - 1986 - dip net and 5 mm minnow seine sampling found 4 non-insect taxa, with Pacific and swamp crayfish dominant, amphipods and <i>Daphnia<i> also present. 1993 - Abundant snails and amphipods noted at the lagoon bottom during fish surveys.		16, 2
Insect	1988 - dip net and 5 mm minnow seine sampling found backswimmers, water boatmen, and diving beetles, and mayfly, dragonfly and damselfly nymphs. 1993 - Amphipods and other aquatic insects noted on the bottom of the lagoon during fish surveys.		16, 2
Other Wildlife	1985 - 1986 Visual surveys and pit traps found 4 amphibian and 7 reptile species. Biweekly visual observation, pit traps, scent stations and live trapping found 17 species; predators were coyote, raccoon, and bobcat.		2, 9, 16
Special Status Species	1988 - Brown pelican, double-crested cormorant, snowy plover, Ca gull, elegant tern, least tern, tricolored blackbird and 5 upland species. 1993 - tidewater goby; 1994 - San Diego horned lizard, Southwestern pond turtle.		9, 2, 16

OUTLOOK			Source
Enhancement Status	No enhancement activity described		2,13, 9
Watershed Management	Working with the US Fish and Wildlife Service, the Marine Corps has developed an ecosystem management plan to ensure that Base training activities are compatible with endangered species habitat needs. In addition, a model is being developed for the watersheds that drain into Camp Pendleton, to predict the effects of various urbanization scenarios on the biodiversity of the area.		8, 13
Pressure	Establishment of invasive exotic species, agricultural runoff		2, 13

Comments	Population data on sensitive species at Camp Pendleton are updated frequently.
SOURCES

1	MEC. 1993. San Dieguito Lagoon restoration project regional coastal lagoon resources summary. 56 pp and appendix.
	This report provides a summary of habitat types, fish, bird and benthic invertebrate populations at 16 coastal wetlands south of Anaheim Bay. It is a synopsis primarily of existing information; sources used in identifying and quantifying habitat types include aerial photographs taken in early 1993. Discusses restoration of habitats at San Dieguito Lagoon given present and historic conditions of other coastal wetlands in the region. This report was prepared as part of the San Dieguito Restoration Project undertaken by Southern California Edison to mitigate for damage to coastal marine resources from the operation of the San Onofore Nuclear Generating Station.
2	San Marino Environmental Associates. 1994. The status and distribution of the tidewater goby, Eucyclogobious newberryi (Pisces, gobiidae), on MCB Camp Pendleton, California. 59 pp and detailed field notes.
	Report of a survey of 8 lagoons on US Marine Corps Camp Pendleton to augment data on population fluctuations, abundance and habitat conditions of the tidewater goby, a federally-listed endangered species.
	Includes discussion of habitat conditions and recommendations for managing habitat to ensure survival of the species. Maps of station locations are included as well as field notes on each haul.
3	Regional Water Quality Control Board. 1994. Water Quality Control Plan for the San Diego basin (#9). 400 pp. and appendices
	The plan includes information on the quality of inland surface waters, coastal waters, reservoirs and lakes and ground water in San Diego County. It identifies beneficial uses supported by these waters and provides a plan for their protection.
4	California Coastal Conservancy. 1989. The coastal wetlands of San Diego county. 64 pp.
	Public education booklet describing ecological concepts and dynamics of San Diego County salt marshes. It profiles the history, current values and problems, protection efforts and public access opportunities at 13 wetland areas.
	The discussion covers watershed processes, littoral and tidal influences, habitat types, significance to migratory birds, and the effects of urban development on the region's coastal wetlands.
5	California Coastal Commission. 1987. California coastal resource guide. 384 pp.
	Provides non-technical descriptions of the Ca coast's natural and cultural resources. Includes explanations of basic geographic, ecological and meteorological concepts as they pertain to coastal features. Prepared at the behest of the state legislature.
6	Slader Buck, US Marine Corps. Personal Communication, January 3, 1996.
7	Dave Pryor, California Department of Parks and Recreation. Personal Communication, January 3, 1996.
8	State Department of Parks and Recreation. 1984. San Onofre State Beach Land Use and Facilities Map.
9	Riefner, Rick. 1994. California Department of Parks and Recreation internal progress report. Prepared for David Pryor. 12 pp.
	Briefly summarizes results of various surveys conducted to identify populations and territories of the California gnatcatcher and other sensitive species at San Onofre and San Clemente State Beaches. Sighting locations are mapped on USGS quadrangles.
10	Carl Steinetz, Harvard University Graduate School of Design. Personal communication, September 9, 1995.
11	Odermatt, John R. and John P. Anderson. 1994. Water resources and pollution prevention in the Santa Margarita River Basin at the U.S. Marine Corps Base, Camp Pendleton, California. Pages 57-74 in Phillip S. Rosenberg ed. Geology and natural history: Camp Pendleton United States Marine Corps Base, San Diego County, California.
	This paper reviews existing information on geology and water resources in the Santa Margarita watershed, identifies environmental conditions and on-base activities that may affect water quality long-term and makes recommendations for protecting water resources within portions of the watershed on Camp Pendleton. The analysis includes assessment of ground water supplies and contaminant transport within sub-basins of the watershed.
12	Fairbanks, Janet. San Diego Association of Governments. Personal Communication, December 8, 1995.
13	California Department of Parks and Recreation. 1973. San Onofre State Beach resource inventory report. Approx. 400 pp.
	Documents the cultural and natural resources of the San Onofre State Beach shortly after its inception. Addresses geology, soils, climate, hydrology, fire, biota and ecological constraints on land use. Includes extensive species lists for aquatic and terrestrial habitats and maps of geology and soils.
14	US Marine Corps. 1993. Training to protect: an environmental outlook. 16 pp.
	Provides an overview of the US Marine Corps' training activities and environmental management programs at Camp Pendleton.
15	Richard Griffiths, US Marine Corps, Camp Pendleton. Personal communication, September 13, 1996.
16	Feldmeth, C. Robert. 1987. Biological resources of the San Mateo Creek area, Camp Pendleton, California. Draft prepared for the U. S. Marine Corps. 122 pp and appendices.
	Biological baseline study of the lower 1.3 miles of San Mateo Creek to enable evaluation of various plans for park-related uses. The study included a comprehensive vegetation survey and community mapping, water quality sampling, and surveys of fish, birds, mammals, amphibians and reptiles. The bird survey discussion includes a description of historic and current local distributions of each resident species. Appendices contain a checklist and cover-abundance table of plant species by community and a list of birds reported in 1984 and 1906 inventories.
17	Department of Water Resources. 1993. Aerial Photograph. Section 1, Flight Line 148.
	1:12,000 aerial photograph of the coast showing lower San Mateo Creek, taken May 13, 1993.

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