Ensuring Long-Term Viability of the Colorado River System Through Early, Proportional Cuts to Water Deliveries During Low Water Years

The Upper Basin of the Colorado River, under current agreements, must prioritize releases between 7.48 and 9.0 million-acre feet of water releases to the Lower Basin each year. These releases control Lower Basin deliveries which, until recently, were at least 8.23 million-acre feet per year. This delivery represents downstream allocations for Mexico, Native American tribes, and Lower Basin states. This report presents a management alternative that allows for proportional releases from Lake Powell based on inflows. Our results in RiverWare (CRSS) modeling show that Lake Powell is kept above power pool elevation longer than without the rule in place.