DEL MAR —The San Dieguito Wetlands Restoration Project will enter its final phase of major construction in September, as the project lead, Southern California Edison excavates about 30,000 cubic yards of sand from the San Dieguito River channel and places it north and south of the river mouth for beach replenishment. Once completed, visitors will notice more water in the wetlands area as hundreds of millions of gallons of ocean water bring fish, plankton and nutrients via the river mouth into the newly created habitats, constantly reinvigorating the ecosystem.
On July 14, final inlet excavation approvals were given, with the mobilization of equipment beginning Sept. 6, with completion expected in early October. Excavating the San Dieguito River mouth inlet is one of the final major construction activities planned for the restored wetlands. It will restore the natural tidal flows between the Pacific Ocean and the hundreds of acres of new and existing habitat that depend on daily seawater tidal influences. The last piece of construction will be to provide shoreline protection for businesses, homes and roads east of Jimmy Durante Bridge, scheduled for April, 2012.
Minimizing interference with any migratory and endangered bird nesting activity is one of the most important components of the inlet excavation. Project biologists will work with U.S. Fish and Wildlife Service and California Department of Fish and Game to monitor the site during construction to protect birds and fish. Scientists have documented nearly a tripling of bird species in the new wetlands since restoration began in September 2006. This spring’s abundance of grunion on Del Mar beaches delayed the final inlet work until September to allow the fish to spawn without interference.
“Once we remove the sand partially plugging the inlet channel, the tidal wetlands will be fully functioning and the daily ocean water flow will support the many acres of vegetation we have planted,” said Patrick Tennant, SCE’s project manager. “As part of our ongoing commitment, SCE will periodically move the sand out of the inlet channel and onto the beach, and monitor the beach for project effects.”
“This is one of the most important components in the overall construction of the wetlands, since the aquatic life, vegetation and wildlife in the nature preserve are all connected and dependent on these daily salt water flows for their sustenance,” said Pam Fair, San Diego Gas & Electric’s vice president of environmental, safety and support services, and chief environmental officer.
The goal of the San Dieguito Wetlands Restoration Project, along with two companion environmental projects, is to offset any adverse impact to ocean ecosystems caused by the San Onofre Nuclear Generating Station. The plant uses ocean water for one of three cooling systems. Although innovative technologies prevent more than 94 percent of marine life near the plant’s intake system from being affected, the system does impact some small fish and fish larvae. SCE and SDG&E also hope to preserve, improve and create a variety of habitats to increase and maintain fish and wildlife, and to ensure protection of endangered species.
Additional information about the San Dieguito Wetland Restoration Project is available at sce.com/wetlands.