Flooding causes explosion of mosquitoes in Stanislaus County; districts to seek FEMA funds

River Road northeast of Newman flooded in February.
River Road northeast of Newman flooded in February. Deke Farrow

People having dinner outdoors this early spring are swatting at pests.

“It’s bad,” said David Heft, general manager of Turlock Mosquito Abatement District. “Our phones are ringing off the hook.”

The winter flooding, the seepage under levees, and standing water in residential back yards have brought out mosquitoes in huge numbers in Stanislaus County.

The county’s two mosquito abatement districts – Turlock and East Side – are hoping to get funding from the Federal Emergency Management Agency to help control the mosquitoes, which are a direct result of the heavy storms in January and February, they say.

President Donald Trump made a fourth emergency declaration Sunday for an estimated $540 million in damages from the winter storms in California, including $274 million for repairs to the Oroville Dam spillway.

East Side and Turlock are hoping a percentage of the federal funding will be approved for mosquito control.

Heft said the inundated areas in his district that need treatment for mosquitoes is so vast, he could spend the district’s entire budget this spring and not treat all the floodwater.

The Turlock district covers the southern part of the county, south of the Tuolumne River and west of the San Joaquin River.

The two districts will need their regular funding in the summer to reduce mosquito populations that transmit potentially deadly West Nile virus.

The mosquitoes appeared earlier than normal this year. The Turlock district is still hiring seasonal employees and contracted for an aircraft from Westley last week to spray wetlands because the airplane it borrows from East Side is waiting for maintenance.

Heft said mosquitoes are going to pester residents this spring regardless of how much insecticide is sprayed. “We are trying to get people to understand it’s a bad year,” Heft said. “Maybe they don’t want to eat dinner outside until we get the mosquitoes more under control and the floodwater recedes.”

East Side General Manager Lloyd Douglass said he hears forecasts that high levels in the Tuolumne and San Joaquin rivers will continue until the end of June.

The Stanislaus River is running high, too, filling bottom land near Knights Ferry and creating perfect habitat for mosquitoes, Douglass pointed out.

East Side has a $2 million annual budget for controlling mosquitoes in Modesto, Riverbank, Oakdale and other communities north of the Tuolumne River. It is early to tell if the district will exceed its budget and dip into reserves this year, but it will spend far more on spray materials than in previous years, Douglass said.

The local agencies are not guessing how much mosquito-control money might be available from FEMA. Douglass said he realizes the Oroville spillway, bridges and other damaged facilities will be the priorities.

The mosquitoes will become a public health problem when the weather warms up in late May and June. Some of the species transmit the West Nile virus when they bite people. The hotter weather allows the virus to amplify more quickly, Heft said.

The soggy conditions set up the county for a larger number of West Nile cases this summer.

Stanislaus County had 30 reported cases of West Nile infection last year, including one death and more than a dozen people hospitalized. In one in five people infected, the illness causes a fever that lasts several weeks, but more severe cases put people in the hospital with a high fever, tremors, seizures and other life-threatening complications.

The managers said residents can help reduce mosquitoes in urban neighborhoods by dumping water from flower pots and containers and keeping their swimming pools clean.

Residents are more vulnerable to mosquito bites in the morning and evening, when mosquitoes are more active.

Ken Carlson: 209-578-2321, @KenCarlson16