Larvae Infestation Forces Early Closure of Reservoir in O.C.

Newport Beach has temporarily stopped using water from Big Canyon Reservoir after several residents found midge larvae in their tap water.

Officials said the reservoir will be out of commission about two weeks--the normal life cycle of the tiny, translucent insects.

The worm-like creatures are no strangers to the reservoir as the weather warms. The city usually closes the 22-million-gallon reservoir in the spring when the larvae hatch. But the unseasonably warm winter has caused the insects to arrive early, city officials said.

“This really does happen every year” as the weather gets warmer, said Assistant City Manager Dave Kiff.

The larvae, harmless to humans, appear as tiny drops in a glass of water. Midge larvae, which infest water supplies worldwide, are 1/16- to 1/8-inch long, smaller than a grain of rice.

An adult can lay a gelatinous mass of up to 3,000 eggs, which attach to various surfaces, such as the sides of reservoirs. After the eggs hatch, the larvae sink to the bottom and feed on algae.

City officials stopped using the reservoir Feb. 25 after residents reported seeing the larvae in their tap water and toilets.

“The only long-term solution is to have a cover, which won’t allow the cycle to start up in the first place,” said City Manager Homer Bludau.

For five years, Newport Beach has been seeking outside sources for the $4.5 million it would cost to put plastic over the reservoir. Recently, officials enlisted the help of Rep. Christopher Cox (R-Newport Beach) to secure federal funding for the cover.

When the city initiated talks with Cox, “it wasn’t our highest priority. It’s our highest priority with him now,” Bludau said.

Bludau said the Orange County Health Care Agency has urged that the reservoir be covered. “It’s only a matter of time before we have to put a cover on,” Bludau said.

After Sept. 11, there was increased urgency to cover the reservoir to protect the water from a possible bioterrorist attack, officials said.