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Annual Inlet Excavation
Reconnecting San Elijo Lagoon with the Pacific Ocean
The small opening, just south of San Elijo State Beach Campground, is the lagoon's only access to the Pacific Ocean. Keeping the inlet open to the ocean is critical to maintaining the health of San Elijo Lagoon. Left unattended, it could remain closed much of the year from buildup of sand transported by high incoming tides, surf, and storm surges.
The inlet is approximately 80% blocked. Tidal circulation is significantly muted as a result of sand buildup in 3 of 4 bays beneath the Pacific Coast Highway bridge and in the main channel. Timing of the excavation is conducted outside the closed grunion season.
The conservancy’s efforts to keep the inlet open to tidal flushing have substantially improved habitat quality relative to the stagnant conditions that previously developed when the inlet was closed for prolonged periods.
WHY WE DREDGE
The inlet becomes intermittently blocked by an accumulation of sand in the tidal channel during the winter storm cycles. The cool weather helps keep oxygen levels in the lagoon in the safe zone. As temperatures rise in the spring and the demand for oxygen increases, an inlet operation is conducted before problems arise.
Typically, the sand berm that forms west of Pacific Coast Highway 101 is breached by excavation equipment. Larger dredging operations remove sand accumulations east of Highway 101 and under the bridge. Clean sand removed from the tidal channel is deposited south onto Cardiff State Beach. Conservancy staff manage these operations.
A major dredging operation to remove accumulated sand and cobbles can cost nearly $100,000. Timing this procedure in the spring after the winter storm cycle greatly increases the chances of continued inlet circulation throughout the warmer summer months.
A MODIFIED LAGOON
Inlet Photomonitoring Slideshow
Improved Tidal Circulation is Funded By:
County of San Diego Department of Environmental Health: