The near-empty San Carlos Reservoir has caused significant ecological damage, including a near-total fish kill due to hypoxia, where oxygen levels in the water dropped critically low. This has forced the indefinite closure of the reservoir, with decomposing fish posing potential health risks. Beyond the ecological impact, the water shortage threatens agricultural output and water supplies for downstream communities. The reservoir's decline highlights the vulnerability of water systems in the Southwest to climate variability and water management challenges.