1957 Aerial View of Lagoon (Photo: Ticor Collection, SD Historical Society)


San Elijo Lagoon is one of San Diego's largest coastal wetlands. It lies along the coast between the cities of Solana Beach and Encinitas, extending inland to the community of Rancho Santa Fe. The reserve covers nearly 1,000 acres of diverse habitat composed of six distinct plant communities.

The primarily shallow-water estuary is artificially disected into basins by Highway 101, the railroad, and the Interstate-5 freeway. On these major traffic arteries, a quarter million cars pass over parts of the reserve each day. More than a century of human modification has resulted in the reduction of the estuary's natural exchange with the ocean. When the lagoon is blocked from receiving oxygen-rich seawater, biological parameters can deteriorate to the point where fish die and troublesome insects reproduce in great numbers. Food supply for birds and other animals is then greatly reduced. When the inlet is closed, the beaches also lose a source of sand.

Successful efforts by County of San Diego, State of California, and San Elijo Lagoon Conservancy have greatly improved water quality, habitat, and biodiversity.


Native American tribes hunted and gathered along the shores of the estuary at least 8,500 years before European settlers arrived. Shell middens, the refuse of hunting-gathering societies, show the earliest inhabitants relied heavily on coastal resources, including foods such as scallops, clams, shark, barracuda, bonito, and abalone. The ocean provided such a rich and constant source of food. These early people stayed at the coast for long periods. More recently, the Kumeyaay occupied the area. They traveled seasonally to take advantage of resources both along the coast and inland.

In 1769, the Portola Expedition named the area San Alejo in honor of Saint Alexius. In the early 1800s Spaniards and other Europeans settled the region and established cattle ranches. The California Gold Rush brought an ever-increasing influx of people. Settlers established the community of Olivenhain, along Escondido Creek, as an experimental farming community. Farmers plowed and planted the riparian corridors upstream of the estuary. It was the first time habitation had radically changed the vegetation and terrain surrounding the lagoon. Non-native plants were introduced that later proved highly invasive.

Between 1880 and 1940 dikes and levees were built that allowed duck hunting, salt harvesting, and sewage settling ponds. The most permanent changes were the construction of the railroad, Pacific Coast Highway, and Interstate 5. Each required supporting berms that restricted water circulation and the natural influx of ocean water.

Above image: In 2003, the Conservancy removed billboards, which had shadowed pristine estuarine views for decades. (Photo: SELC archives)

Other problems associated with construction include increases in sediment from surface erosion and road fill failures. Fine sediment can negatively affect reproductive and rearing success of aquatic populations.

In the 1960s various developments were proposed to transform the lagoon: condominiums, a golf course, a marina, a closed saltwater lake, and even a theme park with water rides. But the community ultimately said no. Citizens, scientists, lawyers, and neighbors who loved the lagoon and its wildlife formed San Elijo Alliance, which successfully fought for its preservation.

Since that time the momentum of public support for the lagoon has continued. A $1.4 million grant from Ford Motor Company in 2000 enabled the Conservancy to purchase additional acreage. The Rancho Santa Fe Foundation has also been instrumental in adding more land to the reserve.

In 2007, County of San Diego, State of California, and San Elijo Lagoon Conservancy signed a 25-year cooperative agreement for the operation and maintenance of San Elijo Lagoon Ecological Reserve. It supersedes the original agreement of May 1981 between the State of California Department of Fish and Game and the County of San Diego, which had expired.

Learn more about the fascinating community efforts to save San Elijo Lagoon. Visit Oral History webpage and downloadable pdf.




Saving San Elijo Lagoon: An Oral History
Visit Oral History web page and downloadable pdf

Spanish Portola Expedition names the area San Elijo (in honor of Saint Alexius).


California Gold Rush brings settlers west. Cultivation upstream causes changes to the watershed.

A standard-gauge railroad is built across the lagoon, constricting the inlet.

Lake Wohlford Dam is built and reduces waterflow through Escondido Creek.


Pacific Coast Highway is constructed across sand dunes.




Berms and shallow ponds for duck hunting are constructed.

The cities of Encinitas, Escondido, and Solana Beach discharge treated sewage into the lagoon, a practice that continues until 1973.


Interstate 5 is built across the midsection of the lagoon.


Private developers begin housing construction around the lagoon. Erosion and pollution further reduce water quality.

Lake Dixon Dam is built, further reducing water flow into Escondido Creek.

Endangered Species Act sets the stage for the designation of sensitive habitat lands in and adjacent to the lagoon.

Coastal Act of California provides protection of coastline.

Management agreement for the reserve is reached between County of San Diego and State of California.

San Elijo Lagoon Ecological Reserve is formally dedicated.

San Diego County builds the first Nature Center in the lagoon.

The Conservancy begins periodic dredging to open the lagoon inlet.

Conservancy receives grant from California Coastal Conservancy to establish Tidal Circulation Endowment to keep the inlet open.

$1.4 million Ford Motor Company grant enables purchase of additional sensitive acreage.

Rancho Santa Fe Foundation transfers title of additional wetlands to the Conservancy and creates an endowment to manage it.

20th Anniversary SELC

County of San Diego, State of California, and San Elijo Lagoon Conservancy sign a 25-year cooperative agreement for the operation and maintenance of San Elijo Lagoon Ecological Reserve.

LEED-Certified San Elijo Lagoon Nature Center replaces former center, and is owned and operated by County of San Diego

Birds of a Feather Gala is held September 17 in honor of the 25th Anniversary of San Elijo Lagoon Conservancy in 2012.

Denise Stillinger received 1st Place in Cox Conserves Heroes, and donated her award to the Conservancy's environmental education program.

The Conservancy purchased the Gateway property, a 3.44-acre parcel adjacent to the southern end of San Elijo Lagoon. A fundraising campaign is under way to own the property outright, called The Campaign for Gateway Park. Once secured, irreplaceable views and wildlife corridors for future generations will forever be protected.

Birds of a Feather Gala is held August 17 and raises more than $200,000 for environmental education programs.

The habitat management team received the Stewardship Development Award from Southern California Wetlands Recovery Project. This award recognizes excellence in fostering stewards through weekly and monthly Lagoon Platoon habitat restoration events.