“According to newly-released projections from the U.S. Bureau of Reclamations, there’s a significant chance that both Lake Powell and Lake Mead — the largest hydroelectric power sources in the country — will stop working in the next few years.” “Five-year projections of future conditions, currently through 2026, in the Colorado River system are typically updated every January, April, and August, while probabilistic results for the 2-year period are updated every month. The “mid- to long-term projections” are generated using a combination of Colorado River Mid-term Modeling System (CRMMS) for the current year’s projections along with the Colorado River Simulation System (CRSS) for projections in year 2 and beyond.
The most recent 5-year projections of future Colorado River system conditions were produced in August of 2021 using the following assumptions:
- Initial Conditions: CRSS was initialized in January 2022 with the August 2021 Most Probable 24-Month Study projected end-of-year reservoir conditions.
- Hydrology: Index sequential method applied to the 1988-2019 historical record, i.e., Stress Test hydrology; a total of 32 future projections (i.e., traces) in the Stress Test hydrology (1 set of initial conditions from the August 2021 24-Month Study x 32 hydrologic inflow sequences).
- Water Demand: Upper Basin demands per the 2016 UCRC depletion demand schedules; Lower Basin demands developed in coordination with the Lower Basin States and Mexico.
- Policy: 2007 Interim Guidelines, Lower Basin Drought Contingency Plan, and Minute 323 are modeled reflecting Colorado River policies.
- Lake Mead provides water for 25 million people in the western US, while Lake Powell supports about 5.8 million homes and businesses between Nebraska and Nevada.
Additional details are available in 5-Year Projections Modeling Approach. All modeling assumptions and projections are subject to varying degrees of uncertainty. Please refer to this discussion of uncertainty for more information…”