Officials concerned swimming pools in Eaton Fire burn zone could turn into breeding grounds for mosquitos

Swarms of insects typically come along with warm weather in Southern California, but public health officials are concerned that a series of abandoned pools located in the Eaton Fire burn zone could turn into breeding grounds for millions of mosquitos. 

Aerial footage shows the hundreds of bodies of water in the midst of the burned out properties throughout Altadena. It's these that sparked the concerns of San Gabriel Valley Mosquito and Vector Control District officials. 

"Well, one swimming pool can breed up to a million mosquitos or grow up to a million mosquitos in one month," said Jason Farned, the district manager of SGVMVCD. "So, with thousands of swimming pools in that area we think that it could be a significant increase."

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That even includes smaller bodies of water like Betsy Kahn's dipping pool.

"Kinda too big to be a hot tub, too small to be a lap pool, but you know it's good when — it was good — when it's super hot," Kahn said. 

She says that her pool's electrical equipment was destroyed and there's no source to change the water, and though it's small, Farned says it's one of many that could be a major problem. 

"In 2023, we have the very first locally transmitted case of dengue fever in Pasadena and we had more cases last year than the following year, so we expect to see some local transmission of dengue this year," Farned said. "And so we're working hard to make sure that any mosquito activity as a result of the Eaton Fire doesn't contribute or increase that risk."

Last year, Los Angeles County reported 11 instances of dengue in residents. Mosquitos are also known to carry West Nile virus, which resulted in at least one county death last year. 

The sitting water has turned into natural ponds at the more than 1,000 swimming pools throughout the burn zone. Farned says that the now murky water creates perfect conditions for mosquitos to grow. 

He said that homeowners can arrange to have their pools drained or removed with the U.S. Army Corps of Engineers, who are handling the ongoing debris removal. 

Larvicide is a shorter term solution, which SGVMVCD officials can spray to treat areas where mosquitos may frequent. That only last for 90 days, however. When ash, debris or chemicals in the water are cleared, Farned also said that "Mosquitofish," a small species that eats mosquitos being bred, can be used. 

"We can start adding fish to some of these swimming pools and once the fish are added to the pool, and one they kind of ... establish themselves, then the fish can control the mosquito population indefinitely," Farned said. 

Last year, Los Angeles County reported 11 instance of dengue in residents.