As Temperatures Rise, So Do Concerns About Disease-Carrying Mosquitoes

The San Gabriel Valley Mosquito & Vector Control District has issued an urgent warning about unmaintained swimming pools in the Eaton fire burn area becoming potential breeding grounds for disease-carrying mosquitoes as temperatures warm across the region. District officials are taking proactive measures to prevent a public health crisis, emphasizing that a single unmaintained pool can produce up to 3 million adult mosquitoes in just one month.

“After a wildfire, pools and other large water sources may become stagnant, creating conditions for mosquitoes to grow,” according to District officials. “These mosquitoes can spread quickly throughout the community and can spread diseases such as West Nile virus and dengue, posing an additional risk to the community.”

Beginning March 17, vector control technicians started to directly treat identified sources of standing water within the burn area. The treatments included larvicides, other mosquito control products, and the distribution of mosquitofish where appropriate.

District personnel are currently participating at the Altadena Disaster Resource Center, providing guidance to property owners affected by the Eaton Fire and assessing unmaintained swimming pools and large sources of standing water within the burn area.

Officials emphasize that only two conditions will guarantee mosquitoes do not grow: “Clean and Functional” or “Empty and Dry.”

For pools that will remain full and non-operational during the recovery phase, the District may provide temporary treatments or mosquito fish distribution while property owners pursue permanent solutions.

“While many property owners may have limited access to their properties or ability to manage stagnant water, we encourage residents to stay informed and reach out if they have any concerns,” the District stated.

Property owners with pools in the affected area are urged to enroll in the District’s SGVpools Eaton Response program. Enrollment can be completed by texting “Eaton Enroll” to (626) 314-6006, emailing “Eaton Enroll” to SwimmingPool@SGVmosquito.org, or calling (626) 314-6006 to coordinate with a vector control specialist.

The District offers free mosquitofish to eligible property owners following an initial assessment of their pools. Through the SGVpools monitoring program, officials will monitor pool conditions during the recovery process and contact property owners when action is needed.

Empty pools require special attention as well.

“A pool is considered ’empty and dry’ only if the pool is kept completely dry and free of debris, year-round,” the District explained. Empty pools need regular maintenance by property owners to remain mosquito-free.

Property owners without pools but with large containers or ponds that could collect water can submit a Request for Mosquito Control Services at:

 https://www.sgvmosquito.org/request-for-mosquito-control-services.

The District notes that under the California Health and Safety Code, property owners are responsible for preventing conditions that allow mosquitoes to grow. However, officials recognize that addressing these issues may be difficult or impossible in the immediate aftermath of the fire.

For property owners considering draining their pools, the District advises consulting with the Army Corps of Engineers or professional contractors during debris removal site walks. However, they caution that “swimming pools without water are prone to costly structural damage” and do not recommend emptying pools.

Property owners can also visit the County’s guidance on draining pools at:

https://recovery.lacounty.gov/rebuilding/#1740615603449-61de5c97-953b.

Currently, the District is assessing environmental conditions, mosquito abundance, and resource allocation to provide the best support services during what they describe as “this unprecedented time.”

Residents can report the status of their pools or get more information at:

https://www.sgvmosquito.org/sgvpools-eaton-area-response.