Bulldozer Helps Mother Nature Flush Stagnant Lagoon

For the sake of the neighbors and some mating birds, a sand barrier has been removed to let stagnant water from the San Elijo Lagoon drain into the sea in Encinitas.

The barrier was bulldozed, and the brackish lagoon water was flowing away Tuesday before it could begin to produce an odor and breed mosquitoes at the 815-acre ecological reserve.

Such barriers are formed by tidal action and must be removed periodically, but the county acted sooner this year because the drought and warm weather threatened an earlier mosquito season. The season usually begins in May.

“We’re kind of acting as mother nature,” Gary Stephany, director of environmental health services for the county’s health department, said Tuesday.

The $20,000 to $40,000 process of punching through the barrier may relieve some unpleasant odor and insect problems for people living by the lagoon, but it does cause a temporary hazard.

Until the lagoon water is entirely flushed away, the county is posting signs along 600 feet of beach warning of possible contamination and that the water fails to meet bathing standards.

Stephany said it could take days to weeks before water samples test clean.

Although draining the lagoon is good for humans, it is also expected to drop the water level low enough to let the Belding’s Savannah sparrow, an endangered species, have access to its breeding grounds.

“It was getting pretty deep. Even the ducks couldn’t reach the bottom to get their food,” said Susan Welker, a park ranger at the reserve. Before the barrier was breached, the water depth in the lagoon ranged from 1 to 6 feet.

Meanwhile, researchers are exploring the lagoon as part of an effort to protect and improve the habitat. The California State Coastal Conservancy granted $90,000 for an enhancement program, and another $50,000 is coming from the county, which owns most of the lagoon, said conservancy spokesman Dewey Schwartzenburg.

The lagoon, one of the largest coastal wetlands in Southern California, supports a variety of wildlife and endangered species in its normally shallow waters.

However, it is “slowly degrading due to sedimentation and poor water quality management,” according to a conservancy report. “Without enhancement and management, the lagoon could eventually lose its value for wildlife.”