On Tuesday, April 11, the Bureau of Reclamation (Reclamation) released a draft Supplemental Environmental Impact Statement (SEIS) for Near-term Colorado River Operations. The plans outlined in the draft SEIS revise the current interim operating guidelines for the management of the two largest reservoirs in the Colorado River system: Lake Mead and Lake Powell. These guidelines were established in 2007 to manage system shortages and have been augmented by emergency actions including the 2019 Drought Contingency Plan. The Colorado River system supplies water to over 40 million people, irrigates almost 5.5 million acres of agricultural land, and supplies hydropower to eight states. However, historically low water levels in Lake Powell and Lake Mead and the threat of “deadpool” conditions require additional actions to protect the system through 2026, when the interim operating guidelines expire. The draft SEIS proposes three alternatives, including a third “no action” alternative. Alternative 1 distributes Colorado River water reductions according to established water rights priority. Alternative 2 distributes reductions evenly amongst all lower basin water users. Reclamation will publish the draft SEIS in the Federal Register on April 14, initiating a public comment period before the final assessment is due this summer.
April 14, 2023
Weekly Wave, vol. 11, no. 15, Water Resources Research Center, Tucson, AZ, April 14, 2023