Arizona's San Carlos Reservoir just collapsed to less than 1% capacity and killed everything in it — and the part that should worry people isn't the drought, it's the contract

Arizona's San Carlos Reservoir, once a large body of water, collapsed to less than 1% capacity, killing most of the fish in it due to severe drought conditions and mandatory water releases for downstream agriculture. The water levels were critically low, leading to hypoxia and a fish kill, prompting an indefinite closure of the reservoir. The historical pattern of droughts and fish kills is showing a compressing timeline, with recovery becoming more challenging against a worsening regional baseline.

The collapse of San Carlos Reservoir highlights the outdated water allocation systems in the Western U.S., built on hydrological assumptions from a wetter century. Wildlife and ecosystems are suffering from the impacts of climate change, as institutions struggle to adapt to worsening conditions. The event at San Carlos serves as a warning sign of what could be a broader pattern of ecosystem collapse, impacting communities and economies downstream of dams and reservoirs across the region.