Reclamation’s Upper and Lower Colorado Regions utilize a suite of reservoir operations models for short-, mid-, and long- term planning. The 24-Month Study, the Mid-Term Operations Model (MTOM), and the Colorado River Simulation System (CRSS) are comprehensive models of the Colorado River system implemented in the commercial river modeling software called RiverWareTM developed by the Center for Advanced Decision Support for Water and Environmental Systems (CADSWES) at the University of Colorado. The models are updated and maintained continually by Reclamation’s Upper and Lower Colorado Regions.

The 24-Month Study is used for one-month to two-year projections. Pursuant to the 2007 Interim Guidelines (ROD), the 24-Month Study is used to set the operating tier for the coordinated operation of Lake Powell and Lake Mead for the following year. Both CRSS and MTOM are used in developing probabilistic projections of future Colorado River system conditions over the timeframe of two years to several decades. The most recent set of projections currently extend through 2026, the year in which the 2007 Interim Guidelines expire.

Projections of future system conditions are most sensitive to assumptions about future Colorado River Basin hydrology. For this reason, Reclamation generates additional projections under different future hydrology scenarios, available at Colorado River System Projected Future Conditions - Alternative Future Hydrology Scenarios. Additionally, Reclamation is actively exploring new methods through its Colorado River Basin Research-to-Operations Program.

Projections of longer term (through 2060) Colorado River system conditions under multiple future hydrology scenarios are available in the Colorado River Basin Water Supply and Demand Study.

NEWS

• Click here to read this story by Sam Metz of The Associated Press
• Click here to read this story by Tony Davis of Arizona Daily Star
• Click here to read this story by Ian James of Arizona Republic

2018, April - Colorado River System 5-Year Projected Future Conditions by the Bureau of Reclamation in the Lower Colorado Division.

Part One - General Modeling Information: (1) Overview; (2) Future Hydrology; (3) Lake Mead and Lake Powell Coordinated Operations; (4) Model Assumptions

• USBR website & archived here (hyperlinks nonfunctional in pdf format (??))

Part Two - Colorado River System 5-Year Projected Future Conditions: (1) Overview; (2) Modeling Approach; (3) Future Projections

• USBR website & archived here 
• USBR Table download & archived here

2020, September - Colorado River System 5-Year Projected Future Conditions by the Bureau of Reclamation in the Lower Colorado Division.

• USBR website - Overview & archieved here

Part One - General Modeling Information:

• USBR website & archived here

Part Two - Colorado River System 5-Year Projected Future Conditions:

• USBR website & archived here
• USBR Table Download & archived here

Part Three - Colorado River System Projected Future Conditions - Alternative Future Hydrology Scenarios:

• USBR website & archived here

Other Information

• 2008 and 2020 Combined (charts only)

REFERENCES

• MTOM Stakeholder User Manual 2.0