San Carlos Reservoir has dropped to less than 1 percent of capacity following an extreme lack of snow in the Gila River watershed. The low water levels triggered a massive fish kill and prompted an indefinite closure of the site on June 5, 2026.
Snowpack in the watershed reached just 2 percent of the 1991-2020 March median this year. April streamflow measured only 39 percent of normal levels, and required releases for agriculture reduced the reservoir to fewer than 400 acre-feet by June.
Satellite images from May 22, 2026, confirm the reservoir held 389 acre-feet, compared with roughly 60 percent capacity in June 2023. Oxygen levels fell sharply as water receded, killing virtually all fish including largemouth bass, channel catfish, and stocked trout.
The San Carlos Recreation and Wildlife Department closed the reservoir indefinitely and warned of health risks from decomposing fish. The site has run dry at least 20 times since 1930, with prior fish kills recorded in 1976 and 2018.
Severe drought continues across the headwaters in New Mexico. A May 2026 NOAA outlook gave a 33 to 50 percent chance of above-average summer rainfall, while strengthening El Niño conditions could increase the likelihood of heavy precipitation in the region.
