The Colorado River, a lifeline for the western United States, is at a critical juncture. As the 2007 guidelines for water allocations expire this year, the future of this vital waterway hangs in the balance. The Colorado River Basin spans seven states, irrigates 5.5 million acres of farmland, and supports over 40 million people. Its administration is governed by a complex framework known as the Law of the River, which includes compacts, treaties, court decisions, and federal statutes. However, the current guidelines, set to expire in 2026, have left stakeholders uncertain about what lies ahead.
The Colorado River Compact of 1922 established the foundational framework for dividing the river’s water between the Upper Basin States (Colorado, New Mexico, Utah, and Wyoming) and the Lower Basin States (Arizona, California, and Nevada). Each basin is annually allocated 7.5 million acre-feet (MAF) of water, with the Lower Basin allowed an additional 1 MAF. However, recent decades have seen low flows, making it challenging to meet these allocations. In response, the Bureau of Reclamation (Reclamation) adopted guidelines in 2007 to reduce water releases based on availability.
Reclamation, an agency within the U.S. Department of the Interior, oversees major river infrastructure, including Hoover Dam, Glen Canyon Dam, and the associated reservoirs, Lake Mead and Lake Powell. These reservoirs are crucial for managing water supply, storage, and distribution. Hoover Dam and Lake Mead serve the Lower Basin, while Glen Canyon Dam and Lake Powell cater to the Upper Basin.
The current management of the river is governed by the 2007 Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead. These guidelines were developed in response to decreasing flows and prolonged drought. They establish a framework for managing water shortages and coordinating operations between the two main reservoirs. The guidelines use specific elevation thresholds at Lake Mead to determine when water deliveries to the Lower Basin States must be reduced, starting when the reservoir falls below 1,075 feet. They also provide a system for coordinating releases from Lake Powell to help maintain Lake Mead’s elevation while protecting hydropower generation and overall water supply reliability.
However, the river’s conditions have evolved since 1922. Droughts, variations in hydrology, and changing water demand have affected reservoir levels. In recent years, the river has experienced declining inflows and record-low reservoir levels. Prolonged drought and rising temperatures have reduced runoff throughout the Western U.S., leaving Lake Mead and Lake Powell well below their historical average water levels. The river now produces only about 12.4 MAF per year on average, far less than the 16.5 MAF available in 1922 when the allocations were originally determined.
To address these challenges, several modifications and supplemental agreements have been implemented since 2007. In May 2019, the seven Basin States agreed on the Drought Contingency Plan (DCP) to supplement the guidelines and reduce the risk of low reservoir levels. The DCP set conservation and operational measures for both the Upper and Lower Basins, including water-use reductions and coordinated releases from Lake Powell and Lake Mead to maintain minimum levels. In May 2023, the Department of the Interior and the Basin States agreed on a consensus-based proposal in which the three Lower Basin States committed to conserving a total of 3 MAF of water before 2026. The federal government will provide compensation for 2.3 MAF of water conserved by those Lower Basin States.
As of February 2025, approximately 52% of the Colorado River’s water is used to irrigate agricultural land, and agriculture accounts for about 80% of total consumptive use in the river. While agriculture remains the largest consumer, municipal and industrial demand has grown steadily, particularly in urban areas such as Las Vegas, Phoenix, and Los Angeles. To help address the supply-demand imbalance, Reclamation has implemented incentive programs that provide financial compensation to farmers who voluntarily reduce their water usage.
As reservoir levels continue to decline, Basin States, Tribes, and federal agencies are exploring strategies to address the supply-demand imbalance and support the long-term sustainability of the Colorado River. The 2007 guidelines are set to expire by the end of this year, leaving open the question of what the Colorado River will look like post-2026. As of January, the Upper and Lower Basin States have been unable to reach an agreement on how to manage the river after the guidelines expire. Following negotiations, the Upper and Lower Basin States submitted separate proposals to Reclamation in March 2024 outlining their preferred approaches for managing the river post-202