History of Batiquitos Lagoon

The Lagoon and other local coastal wetlands probably started their development when the earth began to warm after the ice-age about 18,000 years ago. Before that time, the sea level was about 300 feet lower (because water was frozen in glaciers). As the glaciers slowly melted, the higher water flooded the valleys of the creeks and rivers that were near the ocean, creating deep coastal lagoons along our San Diego coast. Shell species suggest a slow change from a rocky shore to sandy beaches to mudflats. The sea level stabilized 3,500 years ago. About 3,000 years ago, some sort of important environmental change caused a great reduction in marine life, thus decimating many types of shellfish and fish.

The earliest pre-historic site at Batiquitos Lagoon has been dated to 8,000 years ago. Around the shoreline, nearly 200 different pre-historic sites have been recorded. There is evidence of middens (trash heaps made up of discarded shells), fire hearths, and other artifacts left by California Paleo-Indians (9000-3500 years ago) and more recently by the Kumeyaay (about 2300 years ago to about 1800 A.D.) showing that marine shellfish were harvested for thousands of years from Batiquitos Lagoon. This means the lagoon must have been open to tidal flushing at least part of the year in order to allow marine shellfish to survive in the lagoon.


The first white explorers passed through the area in 1769. The San Luis Rey Mission was established 1798, using surrounding areas as grazing land for the livestock. Cattle hides were the “California dollar” in those days. Ranchos and missions traded hides for manufactured goods and converting fat into tallow. The local natives continued using the lagoon resources.

In 1848, the Americans took over the region (which was part of Mexico by then) and the ranchos. The area around the lagoon was opened to homesteading in the 1870’s.


Major changes started to happen to Batiquitos Lagoon due to an increase in trade and transportation. It all started when El Camino Real was built at the eastern end and along Green Valley. California Southern Railroad line was built in 1881. The railroad line was constructed along the coast, with bridge crossing the lagoon mouth. Next, Pacific Coast Highway was built along the coast in 1912 creating another blockage at the mouth. And finally, Interstate 5 was constructed across the Lagoon in 1965. Each of these three lagoon crossings was built on fill dumped into the lagoon, leaving narrow bridged openings, thus blocking the necessary ebb and flow of tides moving in and out, carrying oxygen in and sediment out. As the mouth of the lagoon became blocked, the basins became silted up and shallow, with the water becoming mainly fresh. Starting in 1952, the San Marcos Dam dramatically cut the volume of fresh water flushing through the lagoon.


The city of Carlsbad annexed Batiquitos Lagoon in 1984. The property around the lagoon was owned by the Hunt Brothers of Texas, who had plans to develop this area eventually. There have been many schemes to develop the lagoon such as a theme park called “Captain Nemo’s” and a “Marina Del Rey-like” high-density community. They never panned out. Since then, attitudes toward wetlands have changed. But, by the 1980’s, 90% of the coastal wetlands had already disappeared, and those remaining were in serious trouble.


In the early 80’s, the Port of Los Angeles planned to expand by dredging San Pedro harbor to 20 feet and adding port facilities. This required mitigation to compensate for destruction of coastal habitat. In November 1987, a Memorandum of Agreement was signed by six agencies, the Port of Los Angeles, and the City of Carlsbad. This M.O.A. was signed to form the Batiquitos Lagoon Enhancement Project to restore the lagoon and open a tidal inlet to the ocean. In 1990, the EIR and EIS were complete for the project. Restoration began on the lagoon September 1994 and continued to the spring of 1997.