The Restoration of Batiquitos Lagoon | The Restoration Story

Pier 300 and Peir 400

The History of the Restoration Project

The Port's overall objective for the project was to develop a feasible way to compensate for the loss of marine resources that would occur as part of land construction for new cargo terminals in the Outer Los Angeles Harbor. The mitigation project needed to be big enough to compensate for a large portion of the Port development and needed to be feasible in time to allow the Port to stay on schedule and obtain permits and approvals for the development. Many of the permits and approvals required that the mitigation project be completed or underway before the permit could be issued. Most importantly, the mitigation needed to fit the restoration needs of the area selected. The Batiquitos Lagoon Enhancement Project fit the bill.

Need for Mitigation

In the late 1980s, the Port of Los Angeles recognized that, to accommodate the expected increase in trade with Pacific Rim countries, the Port would need to expand its cargo terminal facilities. The Ports of Los Angeles and Long Beach developed the 2020 Plan, which was designed to help the Port meet rising container terminal traffic through 2020. At the Port of Los Angeles, the plan included recommendations to dredge new and deeper navigation channels to existing land (Pier 300) and to use the dredge material to construct new land in the Outer Los Angeles Harbor (Pier 400). This new land would be used to house new cargo terminals.

The final plan called for constructing 613 acres of new land and for increasing channel depths to -85 feet for bulk terminals and to -50 feet for container terminals. Construction of Pier 400 was going to permanently eliminate marine fish and wildlife habitat that, by state and federal law and policy, had to be mitigated through the creation of equivalent marine habitat.

In planning the proposed developments in the Outer Los Angeles Harbor, Port staff worked with federal and state agencies to develop a biological mitigation plan. The primary participants in this interagency biological mitigation team were USFWS, NMFS, and CDFG. The overall mitigation planning goal was to avoid a net loss in habitat values by permanently creating or restoring similar habitat. In other words, because the project was located in a marine environment, the goal was to ensure that the project caused no net loss of coastal, marine, or tidally influenced habitat with value to fish and birds. After examining many mitigation options, the mitigation team identified the offsite restoration of coastal embayment habitat as the preferred mitigation option.

Need for Restoration

Less than 150 years ago, the Batiquitos Lagoon was a thriving tidal system, but, for most of the past century, the lagoon was largely nontidal. Human intervention had accelerated and altered the natural processes of the lagoon. Poor watershed management, the construction of roads and bridges across the lagoon, the construction of San Marcos Dam, and the discharge of treated wastewater near the lagoon combined with natural processes (such as floods) to degrade the lagoon. For more information on the history of the lagoon, visit the Resources section of the site.

Algal Map in Batiquitos Lagoon (before Restoration)

Three transportation corridors (a railroad bridge, the Pacific Coast Highway, and Interstate 5) were constructed across the lagoon. These corridors constricted the tidal flow of water in and out of the lagoon. Also, agriculture and urban development in the watershed area caused a significant influx of fine sediment into the lagoon. The heavy agricultural and residential land uses in the 30-square-mile watershed that feeds the lagoon also were the source of significant nutrient loading from fertilizers and runoff. All these factors contributed to the degraded state of the lagoon and the closure of the tidal inlet.

By the early 1970s, the lagoon ecosystem had deteriorated notably and, by the early 1980s, had achieved an advanced state of sediment infilling and cultural eutrophication. The wetland habitat in the eastern lagoon was progressively converting to uplands through the expansion of sediment fans. During spring months, algal blooms substantially covered the lagoon, and large mats of green macroalgae and a "green soup" of phytoplankton were common. During summer, the odor of decaying algae spread for 2 or more miles around the lagoon. The nutrient-rich, shallow, closed conditions caused dissolved oxygen, salinity, water temperature, pH, and other water quality characteristics to be highly variable both daily and seasonally.

Heavy surf, caused by major storms in the mid-1980s, replaced the sand on nearby beaches with cobbles, which reduced the appeal of the beaches for recreation and further prevented water from flowing in and out of the lagoon. The lagoon mouth became permanently closed to tidal influence, except for when the mouth was opened mechanically with heavy equipment as part of flood control efforts or to provide nesting areas for endangered bird species that inhabit the lagoon.

Algal Bloom in Batiquitos Lagoon (before Restoration)

The water quality of the lagoon generally was poor. Salinity and temperature varied dramatically between basins, and seasonal variations in the lagoon environment were extreme. In winter the lagoon was nearly a freshwater lake, while in summer and fall the lagoon turned into shallow hypersaline ponds with salt levels of 2.5 to 4 times that of sea water. During some summers, the lagoon dried out entirely. There were no marine fish or marine plants in the lagoon. In fact, because fine sediments continued to be deposited in the lagoon, it was rapidly transforming into upland.

The highly variable, nontidal conditions resulted in a major drop in the diversity of aquatic species (fish and invertebrates) and a subsequent decline in the diversity of other species (e.g., migratory birds) that were dependent on the system. However, despite the significant degradation of the lagoon, it still provided good habitat for birds at some times of the year. In the winter, large numbers of migratory ducks used the lagoon, and in the fall, shorebirds used the lagoon, feeding on the insects that lived in the decaying vegetation mats.

Local groups and agencies recognized that intervention was required to stop the fast deterioration of Batiquitos Lagoon. An enhancement group was established to develop goals and objectives for restoration of the lagoon. An enhancement plan was then developed by the California Coastal Conservancy in 1987. Goals of the plan included restoration of tidal flushing and maintenance of habitat values.