San Luis Rey River Estuary

GENERAL			Source
Site	San Luis Rey River Estuary
Map	Oceanside USGS 7.5' quadrangle
Location	The San Luis Rey River Estuary is located in the City of Oceanside. The watershed extends into unincorporated San Diego County.
Contacts	San Diego County Department of Parks and Recreation, 619-694-3024
	San Diego Association of Governments, 619-595-5370
Approximate Wetland Habitats Acreage	164		5
Approximate Historic Acreage	2,200 acres of high marsh and 58 acres of low marsh are shown on the 1893 USGS map for the lower portion of the river.		5

Ownership in acres	Owner	Acres
	City of Oceanside Oceanside Harbor and the lower river channel.	No acreage specified.	3
	Private The vast majority of the floodplain is privately owned.	Acreages not specified.	3

LAND USE			Source
Land Use Designation	The Oceanside General Plan Land Use Element designates the majority of the San Luis Rey River floodway as General Open Space or Agricultural. The lower part of the river is within a designated Resource Conservation Area overlay in the County General Plan.		1
Onsite Use	Interstate 5 and the railroad disect the estuary. A parking lot is located at the river mouth, providing an overlook of the lagoon.		3
Historic Use	Wetlands in the floodplain were once used for agriculture. The City of Oceanside discharged treated wastewater into the river from 1958 to 1974. The estuary at the mouth of the river was dredged in 1964 to create the Oceanside Harbor.		3
Near Use	Oceanside Harbor, Camp Pendleton Marine Corps Base residential areas and open space are located to the north of the estuary. Oceanside City Beach is to the southwest. Agriculture and residential development is located to the south.		1, 2
Historic Near Use	Agriculture, and groundwater extraction to supply the cities of Carlsbad and Oceanside occurred in the lower watershed.		3

HYDROLOGY			Source
Tidal Influence	I-5 and the railroad limit the tidal influence in the estuary. In addition, a road crosses the beach berm at the mouth, futher restricting tidal flows. No specific information was available on the tidal prism.		3
Watershed Area	565 sq miles		1

Tributaries and Flow	Tributary	Flow	Source
	San Luis Rey River	It is an ephemeral river which stays dry most of the time. In 1977, the peak discharge at the mouth was estimated for a 100-year flood to be 51,000 cubic feet per	1
		second. The river is confined by a 400-foot wide earthen channel bounded by two levees along the lower seven miles. Mineral and aggregate mining has occurred at several sites in the river channel.
Dams	Henshaw Dam, built in 1922, which controls 36% of the watershed, and three small reservoirs.		1, 2
Other Sources	Groundwater in the lowest subbasin of the river has been pumped extensively for urban and agricultural uses; depth to water in 1990 ranged from 6 to 15 feet.		1, 2

WATER QUALITY			Source
General	The mouth of the San Luis Rey River is not listed as an impaired water body by the Regional Water Quality Control Board. Beneficial uses are rec1, rec2, wild, rare, mar and migr.		4, 6
Dissolved Oxygen (DO)	Not specified.		1, 2
Water Salinity	Not specified.		1, 2
Sediment	The mean annual sediment load for the basin below Henshaw dam, approximated from 1970's field and computed data, is estimated to be 97,500 tons.		1

Soil
Soil	Not specified.		1, 2
Habitat	Acres	Vegetation
Estuarine open water	52	Not specified.	5
Coastal brackish/ freshwater marsh	14	Not specified.	5
Riparian	129	1990 - Willow with scattered cottonwoods, western sycamore, oaks and mulefat.	2, 5
Seasonal sand/mud flats	21	Not specified.	5

ANIMAL USE			Source
Birds	1995 report listing sensitive species in riparian and wetland areas of the lower river, named 8 species. No information on total number of bird species available.		1
Fish	Not specified
Benthic Invertebrates	Not specified.
Insect	Not specified
Other Wildlife	1995 report - southwestern pond turtle+ in the lower river.		1
Special Status Species	1995 report - osprey+, black-shouldered kite+, white-faced ibis+, western least bittern+, western snowy plover+, Belding's Savannah sparrow+, least Bell's vireo+, tricolored blackbird+; southwestern pond turtle+ occurred near the river mouth.		1

OUTLOOK			Source
Enhancement Status	A Habitat Conservation Plan has been developed for the river's least Bell's vireo population and is currently being implemented. The plan designates 12 acres of riparian habitat west of I-5 as Conserved Habitat.		2
Watershed Management	The San Luis Rey River Resources Report was prepared to provide a base of information for the development of the San Luis Rey River Watershed Comprehensive Plan.		1
Pressure	Agriculture and urban development within the floodplain and watershed and attendant water, infrastructure and flood management needs; in channel mineral and aggregate extraction.		1
Comments	The principal information available on the San Luis Rey was developed as a characterization of the watershed. Descriptions of the estuary are not provided in detail.

Comments
SOURCES
1	Lettieri-McIntyre & Associates, Inc for the County of San Diego Department of Parks and Recreation. 1995. San Luis Rey River resources report. 200 pp. plus appendices.
	The purpose of this report was to inventory studies conducted within the San Luis Rey River Watershed, identify the existing resources available and make resource-focused recommendations to be considered in future planning efforts. Includes information
	on land use, biology, cultural resources and hydrology. The report is based on existing information. No original field work was conducted.
2	SCAG. 1990. Final Draft San Luis Rey river habitat conservation plan. 139 pp.
	This report was prepared as part of the Comprehensive Species Management Plan (CSMP) for the endangered least Bell's vireo. It was prepared to ensure the protection and recovery of the species within the San Luis Rey watershed. The plan has six major
	components: the planning process, the focused planning area, land use planning, transportation planning, conservation program and action plan. Based on existing information.
3	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. Discussion includes watershed processes, littoral and tidal influences, habitat types, significance to migratory
	birds, and the effects of urban development. Profiles the history, current values and problems, protection efforts and public access opportunities at 13 wetland areas.
4	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
5	MEC. 1993. San Dieguito Lagoon restoration project regional coastal lagoon resources summary. 56 pp plus an appendix.
	This report provides a comparative evaluation of the remaining wetland habitats within the Southern California Bight south of Anaheim Bay. It is a synopsis of existing information. This report was prepared as part of the San Dieguito Restoration Project
	which was undertaken by Southern California Edison to mitigate for damage to coastal marine resources from the operation of the San Onofore Nuclear Generating Station.
6	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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