As The Nevada Independent reported, Southern Nevada held approximately 890,000 acre-feet of Colorado River water in Lake Mead at the end of 2025. The state's water bank, officially called Intentionally Created Surplus, represents nearly three years' worth of Nevada's annual 300,000 acre-foot river allocation.
Under federal rules, most of this banked water cannot be withdrawn if Lake Mead falls below 1,000 feet above sea level. Bureau of Reclamation data showed lake levels sat at 1,037 feet on October 18, while projections indicate levels could drop below the 1,000-foot threshold by March 2028. Because the banked water is mixed with the rest of the lake, it contributes to higher water levels, which federal rules count when evaluating potential water cuts for Arizona, California, and Nevada.
In addition to the Lake Mead credits, the Southern Nevada Water Authority held about 614,000 acre-feet in Arizona underground banks, 342,000 acre-feet in Las Vegas Valley groundwater, and 330,000 acre-feet with the Metropolitan Water District of Southern California at the end of 2025.
