More than a year after crews finished the first sweep of fire-damaged swimming pools, the San Gabriel Valley Mosquito and Vector Control District is still supervising 889 pools in the Eaton Fire burn area.
That October count, reported by Pasadena Now, is the practical remainder of a response that began with 1,475 nonfunctional pools. The district's own account, on its Eaton-area response page, says it and partner agencies completed initial mosquito-control treatments on all of them.
From Priority Pools To A Full Sweep
District crews started on fire-damaged Altadena pools in March 2025, beginning with about 700 priority pools near homes. By the end of June 2025, Pasadena Now reported, the initial operation covered all 1,475 identified nonfunctional pools.
The work was not a one-agency job. The district lists the California Governor's Office of Emergency Services, the Greater Los Angeles County Vector Control District, the Orange County Mosquito and Vector Control District, and the Los Angeles County Department of Public Health as partners. Cal OES supplied pesticide, protective equipment and personnel; Greater L.A. sent specialists; Orange County provided mosquito fish.
Technicians later completed four rounds of treatment at more than 1,400 high-risk pools, the district says. Through source-reduction work with property owners, nearly 500 pools are now functional or gone. The Eaton Fire itself damaged more than 1,400 swimming pools in the Altadena region; the larger 1,475 figure is the set the district identified as nonfunctional and worth treating.
The Money Ran Short, Then Arrived
The mid-recovery math was ugly. In May 2025, the Los Angeles Times reported that the district had spent $307,000 applying pesticide to about half of the 1,475 pools and had asked for another $302,000. That request was meant to finish the first treatment on the rest and to pay for two follow-up treatments on all of them.
The initial sweep was nevertheless done by the end of June. The district later reported receiving $500,000 in state funding for mosquito control in the burn scar. A district coalition, with advocacy from the San Gabriel Valley Legislative Caucus, tied that sum to the 2025-26 state budget and said it had gathered more than 25 letters of support. The district's public account does not include a budget bill or other primary state record alongside that figure.
The district has also described media coverage as what moved standing water in wrecked backyards from a neighborhood nuisance to a public-health priority. It says outreach to displaced residents ran through a response webpage, town halls, the disaster recovery center, text messages and direct survivor support. The district serves more than 1.5 million residents in 26 cities and is one of five vector-control districts in Los Angeles County.
What Supervision Looks Like Now
October's 889 is not 889 identical puddles. Pasadena Now, citing the district, said 250 supervised pools were empty and dry, 47 were getting larvicide, and about 17,000 mosquito fish had gone into 590 pools.
Those three categories add up to 887, two short of the stated 889. The report did not explain the difference. An empty pool is a different problem from a full one that cannot be run, and a fish stocking is not the same intervention as another round of pesticide.
For full, non-operational pools in the Eaton Area Recovery Phase, the district says on its SGV Pools page that it may provide temporary treatments or mosquito fish. It is asking burn-area pool owners to enroll in that Eaton response program or call (626) 814-9466.
Disease Pressure Did Not Stay In The Burn Scar
The pools were treated because standing water can produce mosquitoes that carry West Nile virus and dengue. In 2025, the district reported, mosquito populations in the burn area stayed at seasonal averages and West Nile virus was not detected there.
That is a narrower result than a clean bill for the valley. On its emergency-response account, the district said the main local West Nile vector, Culex quinquefasciatus, stayed within its expected range, while other West Nile vector species increased. By September 3, 2026, the San Gabriel Valley Tribune reported 105 virus-positive mosquito samples in the San Gabriel Valley, above the five-year average. Those samples are a valley-wide tally, not a burn-area case count.
The district has said the Eaton work helped keep mosquito abundance and disease activity within expected ranges against that five-year comparison. Its own species breakdown is less tidy: one important vector held, others did not, and the wider valley's 2026 virus detections have already cleared the recent average. The 889 pools still on the list are where that distinction gets tested next, one dry basin, one larvicide treatment, or one stocking of mosquito fish at a time.
