What we do: Habitat Restoration

Inlet Maintenance

Keeping the inlet open to the ocean is critical to maintaining the health of San Elijo Lagoon. The Conservancy’s efforts to maintain 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.

Dredging of the inlet (Photo: SELC Archives)

The San Elijo Lagoon Conservancy experimented with different types of inlet openings between 1994 and 1999. These experimental openings yielded a method that kept the inlet open to the ocean for an average of 79% of the year.

In 2001, a long-term financial endowment was established to actively fund maintenance of tidal flushing. Efforts to keep the Lagoon open to tidal circulation have shown that significant ecological benefits result from increased tidal flushing, as evidenced by increased diversity and abundance of fish, improved water quality, reduced production of mosquitos and midges, enlarged nesting areas for California least terns, Belding's savannah sparrows, and Western snowy plovers, and increased foraging by birds. These ecological improvements have also fostered significant public enjoyment of the lagoon.

However, much more work is needed to sustain the productivity and to enhance the carrying capacity of the Lagoon. Generally 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. A major dredging operation to pull out the sand from the tidal channel and remove the cobbles can cost upwards to $80,000. Timing this procedure in the spring after the winter storm cycle increases the chances of the inlet staying open throughout the warmer summer months. Previous experimental openings showed that a dredging operation in the winter has little chance of keeping the inlet open during the winter storm season.

Dredging of the inlet (Photo: SELC Archives)