Now's the time to dump out rainwater to prevent mosquitoes later
Last weekend, a Contra Costa County resident sent the District a picture of a mosquito that had landed on his leg. The resident was surprised mosquitoes were out already; after all, it's still technically winter.

Here in Contra Costa County, however, the last few weeks before the first day of spring tend to be fairly sunny and somewhat warm. When you add a day or two of rain followed by increasing warmth, it becomes a recipe for mosquitoes.
Dumping out rainwater denies mosquitoes a place to develop from egg to adult.
Look for Standing Water and Dump it Out

Mosquitoes lay their eggs in or near water. Once in water, the eggs can develop into adult mosquitoes in a matter of days. The warmer the weather, the faster some mosquitoes grow from egg to adult. Female mosquitoes are the ones who can bite people and can spread the causative agents for mosquito-borne disease. That is why dumping out rainwater is so important. By dumping out sources of water, you take away places where mosquitoes can grow into biting adults.

With this week's rain followed by sunny days in the forecast, the Contra Costa Mosquito & Vector Control District (District) is asking county residents to walk around your property and dump out any amount of standing water, because even a small amount of water can produce mosquitoes.
Here are various places where rainwater can collect that you might not expect, but mosquitoes could find.
That's why it's important to dump out rainwater to prevent mosquitoes.
Residential yards are often the #1 source of mosquito production in a community. Anything that can hold just tablespoons or more of water, such as toys, flowerpot saucers, neglected swimming pools and hot tubs, bird baths, clogged rain gutters, and more, can produce mosquitoes. And, of the 23 species of mosquitoes present in Contra Costa County, a few may be active year-round. When you eliminate all types of standing water on a regular basis, you reduce the risk of mosquito-borne illness for your family and your neighbors.

Show Us How You Dump it Out

The District appreciates your efforts to dump out rainwater to prevent mosquitoes and we'd love to see all of the places where you've found water, especially the unexpected outdoor locations. Send photos of your efforts to the District. If you would like to include permission to share your pictures on social media, we'd be proud to share how you're making an effort to protect public health right here in Contra Costa County.

Request District Service

If, after you have dumped out all of the standing water you can locate on your property, you still get bitten by mosquitoes while in your front or backyard, contact the District. The District provides the public health service of inspection and control of mosquitoes in Contra Costa County.

If you have a residential pond, a swimming pool, or a hot tub on your property that you no longer use, but is holding water, you can also request the District's mosquitofish service. Due to the pandemic, the District's mosquitofish pick-up service is no longer available. Instead, the District now offers a mosquitofish service that involves a District employee conducting an inspection and if mosquitofish are the appropriate solution to the mosquito issue on the property, the District employee will place the fish in the water source.

More information about the importance of eliminating mosquito sources can be found here and thank you for dumping out rainwater to prevent mosquitoes.
Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord. Contact the District to report mosquito and vector problems online or at (925) 685-9301.