Colorado River Shortage
ARIZONA - STRONGER TOGETHER
The Colorado River Basin continues to experience drought exacerbated by the impacts of climate change. The Colorado River Basin is in a Tier 1 shortage for 2024. This represents a 512,000 acre-foot reduction to Arizona’s Colorado River water supply, constituting 30% of CAP’s normal supply, about 18% of Arizona’s Colorado River supply, and just under 8% of Arizona’s total water use. Nearly all the reductions within Arizona have been taken by Central Arizona Project (CAP) water users. These reductions were determined by the CAP priority system – the result being less available Colorado River water for central Arizona agricultural users.
The Lower Basin States’ Alternative for Post-2026 Operations includes two major concepts:
- Maximum system contents – System contents are based on the volume in seven major reservoirs that is available for release, in millions of acre-feet (MAF).
- Reduction determination – Reductions are based on the available system contents, as follows:
- Initial Reduction Zone (69% – 58%): Reduction to Lower Basin water uses increasing from 0 to 1.5 MAF
- Static Reduction Zone (58% – 38%): Consistent 1.5 MAF reduction to Lower Basin water uses
- Basinwide Reduction Zone (38% – 23%): Additional reductions to protect the system, increasing from 1.5 MAF to 3.9 MAF
- Maximum Reduction Zone (23% and below): Consistent 3.9 MAF reduction
Meetings
Shortage Impacts
Colorado River shortage will have various impacts on available water supply to CAP water users.
Documents
Media Statements
- Lower Basin Proposes New Colorado River Approach
- Arizona, California, Nevada issue statement on release of the Final Environmental Impact Statement for Near-Term Colorado River Operations
- Six States Meet Deadline with “Consensus-Based Modeling Alternative: Joint ADWR/CAP Statement”
- Colorado River States Submit a Consensus-Based Modeling Alternative to Bureau of Reclamation
- Joint ADWR/CAP statement in response to the U.S. Department of the Interior announcement regarding 2023 Operating Conditions for Lake Powell and Lake Mead
- Statement from CAP General Manager Ted Cooke in response to the announcement from the Bureau of Reclamation Commissioner Camille Touton regarding deteriorating conditions on the Colorado River system
- Joint ADWR/CAP Opinion Piece (Arizona Republic, Sunday, May 8) — Colorado River under stress – Arizona’s response
- Joint ADWR/CAP press release regarding the U.S. Secretary of the Interior’s declaration of a Tier 1 shortage on the Colorado River for 2022
- April 24 Month Study joint statement
- Arizona’s shortage preparedness joint statement
More Information
Visit River Updates on Know Your Water News.