Water & Drought

How do you stop mosquitoes from invading rain barrels?

Q: I’ve been saving water in our “green” poly trash can. I suspect we have about 40 gallons worth. Now, I have mosquitoes. What can you suggest?

Darrell Kaff, Roseville

Mosquitoes tend to gravitate to any standing water, no matter how small. And now is the time of year when mosquitoes come out of hibernation and start breeding. But there are ways to save water and help prevent mosquitoes, too.

“Given the drought, saving water is certainly a good idea — if done properly,” said Luz Rodriguez of the Sacramento-Yolo Mosquito and Vector Control District. “However, it becomes imperative that homeowners take the proper precautions to ensure they are not producing mosquitoes. In hot weather, mosquitoes can go from an egg to an adult in as little as 7 to 10 days, posing a health threat for diseases such as West Nile virus.”

The district offered these tips that can help prevent mosquitoes if you are saving water:

• It’s always best to use a container made specifically for saving water (such as a rain barrel) rather than buckets, garbage cans or other home-made containers. Rain barrels are designed to keep bugs and debris out of the water, helping to prevent mosquito invasions.

• It is extremely important to


use a mosquito-proof screen to seal and cover the rain barrel or other water-saving container. Mosquito-proof screen is a very fine mesh, usually 1/16 of an inch. If the barrel is covered, this will reduce the likelihood of mosquitoes becoming a problem.

• Keep the rain barrel lid and connectors sealed to help keep bugs out.

• Ensure that the water you save is free of organic material such as leaves and other debris.

• Be sure to always remove the water that pools at the top of the barrel at least once or twice a week.

• If possible, place your barrel on a surface that will soak up any water that overflows so it doesn’t pool and create a mosquito habitat.

• Regularly inspect your rain barrel system. Check for cracks or leaks. Be sure that all fittings and seals are intact and that no water accumulates on the ground around the barrel.

• Clean the barrel on a regular basis. Drain it completely and clean it out at least twice a year.

• If the barrel is holding a lot of water, get free mosquitofish. Each one can eat at least 300 mosquito larvae per day. Residents can request mosquitofish online at



• If needed, consider using a larvicide product that kills mosquito larvae. A variety of products are available at garden center that will kill the larvae but not harm plants.

Submit your question for The Sacramento Bee’s water team.