Overview
- Officials closed San Carlos Reservoir indefinitely on June 5 after oxygen levels fell and what the San Carlos Recreation and Wildlife Department called a near-total fish kill.
- Satellite and USGS data show the lake held about 389 acre-feet on May 22, 2026, equal to less than 1% of its capacity and exposing the river channel and reservoir bottom.
- The 2026 mountain snowpack in the Gila watershed was about 2% of the 1991–2020 March median, which cut spring streamflow to roughly 39% of normal while mandatory releases for downstream agriculture further drained the reservoir.
- The die-off affected virtually all resident and stocked species, including largemouth bass, crappie, bluegill, channel and flathead catfish, brown trout, and rainbow trout, and officials warned decomposing fish pose public-health risks for boaters and anglers.
- Recovery is uncertain because past mass kills have taken years to reverse; NOAA’s May outlook gives a 33–50% chance of above-average summer rain that could help refill the lake but would not immediately restore the ecosystem or local fishing and tribal livelihoods.