Los Penasquitos Lagoon

GENERAL			Source
Site	Los Penasquitos Lagoon
Map	Del Mar USGS 7.5' quadrangle
Location	Northwestern border City of San Diego, directly south of City of Del Mar
Contacts	Los Penasquitos Lagoon Foundation, (619) 729-3261
	Torrey Pines State Park, (619) 755-2063
Approximate Wetland Habitat Acreage	636		1
Approximate Historic Acreage	425 (acreage describes only low, or salt, marsh)		16

Ownership	Owner	Acres
	California Department of Parks and Recreation Acreage is approximation of ownership within the lagoon, total park area is 1,526 acres which includes extensive uplands.	Approximately 569	1
	State Coastal Conservancy	20	1, 9
	City of San Diego	Approximately 6	9
	Private (railroad berm)	Approximately 41	1, 9

LAND USE			Source
Land Use Designation	City of San Diego - Open Space, Sensitive Coastal Resource Overlay Zone		2
Onsite Use	Power lines, sewage pipelines and a pumping station, and a bermed railroad track that has spanned the lagoon since 1925; in addition, Hwy 1 crosses the mouth.		1
Historic Use	Native American settlements; treated sewage was deposited into the lagoon from 1962 to 1972.		1
Adjacent Use	Beaches to the north and south of the mouth are state recreation areas; Carmel Valley Rd and a parking lot with residential and commercial uses beyond bound the site to the north; Sorrento Valley Rd and I-5 bound the salt marsh to the east.		1, 2
	Residential development and a roadway extend to the northeast, Los Penasquitos Canyon Preserve extends to the southeast, Torrey Pines State Park and small areas of light industrial lie atop bluffs to the south.
Historic Adjacent Use	Agriculture, including grazing.		1

HYDROLOGY			Source
Tidal Influence	The ocean inlet is restricted by the Highway 1 crossing and without mechanical clearing would be blocked with sediment for extended periods; an active management program is targeted towards keeping the mouth open most of the time;		1, 11
	when the mouth is open, the tidal reach is impeded by the railroad and sewer berms.
Watershed Area	95 sq miles		1

Tributaries and Flow	Tributary	Flow
	Carmel Creek	Historically seasonal, now year-round due to development in the watershed; 1985 estimate of the 100-yr peak at a point near the mouth was 9,600 cfs.	1, 13
	Los Penasquitos Creek	Historically seasonal, now year-round due to development in the watershed; the channel is concrete-lined for 2 stretches in its lower reach; a 1982 estimate of the 100-yr peak at a point near the mouth was 16,300 cfs.	1, 13, 2
Dams	None identified
Other Sources	Eight storm drains empty into the lagoon.		1

WATER QUALITY			Source
General	Dependent on the amount and timing of precipitation, and the timing and duration of ocean inlet opening; in 1994 the total rainfall was approximatley 10 in. with no flooding and the ocean inlet was open 365 days. Listed in 1994 as an impaired water body;		11, 5, 17, 18, 19
	the draft 1996 list indicates standards for sediment and coliform exceeded for selected uses. Designated Beneficial Uses: rec1, rec2, biol, est, wild, rare, mar, migr, shell.
Dissolved Oxygen (DO)	1994 - samples were taken every 2 weeks at 3 stations in the main channel on both sides of the railroad berm. The range of a.m. bottom concentrations averaged for the site was approximately 4.5 - 8.5 mg/l. Temperatures were measured but not reported.		5
Water Salinity	1994 - samples were taken every 2 weeks at 3 stations in the main channel on both sides of the railroad berm. The range of bottom concentrations averaged for the site was approximately 2 - 33 ppt.		5
Sediment	In 1982 the combined mean annual sediment load for the lagoon was estimated to be 69,700 cub yd, the projection for 2002 was146,000 cub yd; between 1968 and 1985 the ground elevation at the lower end of the Carmel Vly. culverts was raised over 6 ft.		1

Soil			Source
Soil	4 types of fine silts and clays overlay marine and river sand. All 4 soil types are classified as extremely erodible in source areas.		1

Habitat	Acres	Vegetation	Source
Marine intertidal (beach)	4	Not specified	16
Tidal and nontidal sand and mud flats	25	Not specified	16
Estuarine open water	30	1994 - Widgeon grass rare	Ac 16 Plants 5
Salt Marsh (Approximately 25 acres of salt marsh were converted to riparian and cattail marsh 1974-1985; 3.5 more acres were converted 1986-1989 due to sedimentation and increased freshwater flows.)	271	1994 - pickleweed, saltgrass, alkali heath, fleshy jaumea were dominant, cordgrass was absent, salt marsh daisy+ was common around salt pannes, and horseweed* was found throughout the NE lagoon.	Ac. 16, (1, 5, 6) Plants 5
Coastal brackish/freshwater marsh	15	1985 - dense stands of cattail along with spiny rush and Ca. bulrush, also pickleweed, alkali heath and curly dock.	Ac. 16 Plants 1
Riparian	106	1985 - alkali heath, pickleweed, curly dock*, fleshy jaumea, and alkali bulrush dominant in shrub-scrub areas; arroyo willow, willow baccharis, giant reed dominant in forested areas.	Ac. 16 Plants 1
Transition	84	Not specified	16

ANIMAL USE			Source
Birds	1994 - monthly surveys found 64 water-associated species, 183 species total. A 1993 survey of breeding Belding's Savannah sparrows# found 156 pairs; 1 pr of light-footed clapper rails# identified in 1994 and 1995.		7, 3, 10
Fish	1994 - winter and summer bag seines at 3 stations in the main channel, up and downstream of the railroad berm found 11 species from 9 families. Species composition varied from previous years; topsmelt was dominant, also abundant were arrow goby,		5
	Ca. killifish, and deepbody anchovy. Yellowfin goby*, first recorded in 1986 were present.
Benthic Invertebrates	1994 - cores at 3 stations in each season found 33 taxa, including polychaetes, small crustaceans, bivalves and ghost shrimp; crabs and a nudibranch were also observed; densities were reported as being similar to those found in 1993.		5, 12, 4
	2nd quarter report for 1995 sampling found oriental shrimp* common in seines at the head of the largest channel.
Insect	1994 - Unidentified fly larvae found in core samples.		5
Other Wildlife	1985 - No additional types of wildlife particular to wetland systems reported; predators present included racoons and feral cats and dogs.		1
Special Status Species	Salt marsh daisy, common loon, west. grebe, brown pelican, white-faced ibis, west. snowy plover, long-billed curlew, Ca. gull, elegant tern, light-footed clapper rail# Belding's Savannah sparrow#, Ca. gnatcatcher, no. harrier,		5, 7, 3
	Cooper's hawk, merlin, peregrine falcon.

OUTLOOK			Source
Enhancement Status	An enhancement plan was prepared in 1985 with an update underway in summer 1995; all of the lagoon is in public ownership; dredging in Dec 1989 re-opened an area of remnant marsh near the parking lot and deepened the main channel from the mouth to the		1, 14, 15, 9
	railroad embankment. There is an active program to keep the mouth open which involves annual monitoring of physical, chemical and biological parameters. The pump station and sewage lines are being permanently retired. The City is required
	to provide for enhancement of tidal flow at the mouth of the Lagoon by mechanical means (up to 4 times/year). The City must also prepare restoration plans for approximately 24 acres on 2 parcels.
Watershed Management	Approximately 3650 acres of Los Penasquitos and Lopez canyons are in the Los Penasquitos Canyon Preserve; goals for the preserve are preservation and enhancement of natural and cultural resources, and provision of recreation and education.		8, 10, 14
	The City is required to identify, repair, and maintain on a permanent basis erosion control devices it owns within the lagoon watershed; a biological monitoring program for the watershed is under development.
Pressure	Sedimentation, continued urban development in the watershed, proposed re-alignment and widening of Carmel Valley and Sorrento Valley roads, exotic vegetation and fauna.		1, 4, 2

Comments
SOURCES
1	Los Penasquitos Lagoon Foundation and the State Coastal Conservancy. 1985. Los Penasquitos Lagoon Enhancement Plan and Program. 90 pp. and appendices.
	Details the existing environment, the enhancement and restoration plan for the lagoon, and an environmental impact assessment of the various proposed alternatives. The existing setting section covers soils and water, natural resources, and land
	use. Consultants analyzed and modelled the hydrology and hydraulics of the lagoon system, mapped and described the lagoon habitats, and conducted bird and wetland surveys.
	Appendices include information on the regional wetland context, the history of lagoon mouth openings, and an annotated bibliography.
2	City of San Diego. 1994. Torrey Pines Community Plan Update and North City Local Coastal Program Land Use Plan Amendment. Environmental Impact Report. 63 pp. and Response to Comments.
	This report details the environmental setting and analyzes the potential environmental impacts of the Community Plan. The impact analysis focuses on traffic and circulation, air quality, biology, hydrology
	and water quality, visual quality, and cultural resources. No indication of original field work. Analysis based on information available to the City of San Diego.
3	Boland, J. 1993. The breeding population of Belding's Savannah sparrows at Los Penasquitos Lagoon. Report to the Los Penasquitos Lagoon Foundation. 6pp.
	Provides a detailed summary of a census of Savannah sparrows in the Los Penasquitos Lagoon conducted between 3 - 13 May 1993. Includes a map showing the location of the breeding territories.
4	Williams, G. D. and D. R. Gibson. 1995. The physical, chemical and biological monitoring of Los Penasquitos Lagoon. Quarterly Report prepared for the Los Penasquitos Lagoon Foundation. 16 pp.
	Reports results of water quality, benthic invertebrates and fish monitoring at the Los Penasquitos Lagoon. Sampling took place between 11 December 1994 and 11 March 1995. Discussion includes comparisons with
	data from previous years. Concludes with recommendations for mouth opening strategies and future studies.
5	Gibson, D. R., G. D. Williams, and J. B. Boland. 1994. The physical, chemical and biological monitoring of Los Penasquitos Lagoon. Final report for the Los Penasquitos Lagoon Foundation. 20 pp.
	Reports results of monitoring water quality, benthic invertebrates, fish, and salt marsh vegetation of the Los Penasquitos Lagoon. Sampling took place between 28 December 1993 and 22 October 1994.
	Discussion includes comparisons with data from previous years. Also includes recommendations for mouth opening strategies and future studies.
6	Nordby, C. 1990. Physical-chemical and biological monitoring of Los Penasquitos Lagoon. Final report prepared for the Los Penasquitos Lagoon Foundation. 8 pp.
	Provides a detailed assessment of the physical and chemical characteristics, benthic invertebrates, fish, and salt marsh vegetation of the Los Penasquitos Lagoon. Sampling took place between December 1989 and April 1990. Results are presented
	for water quality, benthic invertebrates, fish, and vegetation. Concludes with a summary and recommendations for additional studies.
7	San Diego Audubon Society. 1994. Penasquitos Bird Census for 1994. Don Adams Count Leader. Unpublished survey data. 11 pp.
	Summary of monthly survey data collected by the San Diego Audubon Society in the Penasquitos Lagoon. Includes field notes listing observers and their remarks.
8	City of San Diego. 1992. Final Environmental Impact Report for the Los Penasquitos Canyon Preserve Master Plan. 227 pp. and Response to Comments.
	Report outlining the potential environmental impacts associated with the Los Penasquitos Canyon Preserve Master Plan. Includes information on environmental setting and environmental analysis for land use, visual quality, erosion, water quality,
	biology, cultural resources, and circulation for the Los Penasquitos Canyon and its tributary Lopez Canyon. Based on existing studies and biological field surveys conducted by the County of San Diego in November, 1987.
	In addition, various background studies are incorporated by reference, including the SANDAG 1992 Los Penasquitos Lagoon Watershed Management Plan.
9	Highway 56 Settlement Agreement among Sierra Club and League for Coastal Protection (petitioners); Calif. Coastal Commission (respondent); and Caltrans and the City of San Diego (real parties). 16 pp.
	This agreement details a set of actions that Caltrans and the City of San Diego promise to perform in and around the Los Penasquitos Lagoon in response to litigation over widening of roadways in the vicinity. Includes a requirement for a tidal flow
	enhancement program and restoration of approximately 24 acres on 2 parcels.
10	Zembal, Richard. 1995. Status and distribution of light-footed clapper rails in California, 1980-1995. Preliminary report to the California Department of Fish and Game. 28 pp.
	Results of the 1995 survey of breeding light-footed clapper rails in California. The report incorporates data from 15 years of annual surveys and disusses population trends for the region and at each of 36 sites censused. Trends are tied to
	ecological conditions at each site and the author identifies possibilities for improving habitat.
11	Boland, John. 1993. Maintaining the mouth at Los Penasquitos Lagoon 1991-1993: review and recommendations. 10 pp.
	An assessment of efforts to keep the Los Penasquitos Lagoon mouth open from 1991 to 1993. The report characterizes the beach and beach processes at the mouth, describes cobble removal efforts during the period, and makes recommendations for future cobble
	removal. It includes analysis of sediment height and channel shape before and after cobble removal. Prepared by the Pacific Estuarine Research Laboratory for the Los Penasquitos Lagoon Foundation.
12	Boland, John. 1993. The physical, chemical and biological monitoring of Los Penasquitos Lagoon. Final report for the Los Penasquitos Lagoon Foundation. 20 pp.
	Reports results of water quality, benthic invertebrates, fish, and salt marsh vegetation monitoring at Los Penasquitos Lagoon. In addition, surveys were done to determine abundances of the salt marsh daisy and Belding's Savannah sparrows.
	Sampling took place between 20 September 1992 and 20 September 1993. Discussion includes comparisons with data from previous years. Also includes recommendations for future studies and strategies for opening the lagoon mouth.
13	Nordby, Chris. 1989. Physical/chemical and biological monitoring of Los Penasquitos Lagoon. Final report report prepared for the Los Penasquitos Lagoon Foundation. 33 pp.
	Reports results of 2 years of monitoring water quality, benthic invertebrates, fish and invertebrates of the Los Penasquitos Lagoon. Sampling included 2 surveys of the Belding's Savannah sparrow population. Monitoring took place
	between 16 June 1987 and 2 June 1989. Discussion includes comparisons with previous years' data. The report concludes with recommendations for future studies and strategies for opening the lagoon mouth.
14	Joan Jackson, Los Penasquitos Lagoon Foundation. Personal communication, June 9 and 28, 1995.
15	Mike Wells, Torrey Pines State Park. Personal communication, June 19, 1995.
16	San Diego Regional Water Quality Control Board. 1994. Water quality control plan for the San Diego basin. Approximately 225 pp. and appendices.
	The plan designates beneficial uses and associated water quality objectives for inland surface waters, coastal waters, reservoirs and lakes and ground water in San Diego County. It includes a discussion of applicable policies and statutory
	requirements and identifies measures for achieving water quality objectives. It also describes ongoing monitoring and assessment programs. Appendices contain summaries of regional growth forecasts and criteria for organic and inorganic constituents.
17	State Water Resources Control Board. 1994. List of impaired water bodies.
	Developed as part of the Water Quality Assessment of the State's major waterbodies. Separate lists are developed to rate waterbodies as Good, Intermediate, Impaired or Unknown Quality. Impaired waters are those not expected to attain or maintain
	water quality standards. The state list is a compilation of those developed by the nine regional boards. Lists of impaired water bodies are also known as 303(d) lists as they meet a requirement of section 303(d) of the federal Clean Water Act.
18	San Diego Regional Water Quality Control Board. 1996. Draft 303(d) list.
	A proposed list of waterbodies in the San Diego Basin that do not or are not expected to attain water quality standards after application of required technology-based controls. Specifies selected beneficial uses and criteria assessed,
	and the percentage of samples in which criteria were exceeded. It also identifies waterbodies for which previous assessments are no longer applicable.

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