Western states reach Colorado River water deal

After a year of often tense negotiations among seven western states that depend on Colorado River water, the United States Department of the Interior announced on May 22 an agreement among the states to voluntarily reduce their allocated water rights in exchange for short-term payments while infrastructure projects to address Colorado River shortages longer-term are being completed.

The payments, totaling about $1.2 billion, will come from the Inflation Reduction Act of 2022, and will be divided among water districts, cities and tribes that reduce their water usage. The three lower basin states (Arizona, California and New Mexico) agreed to conserve at least an additional 3-million-acre-feet (3.7 billion cubic meters) of Colorado River water in the lower basin by the end of calendar year 2026, with at least 1.5 MAF of that total being conserved by the end of calendar year 2024. That amount is about 13% of the three states’ total allotment. Representatives of the three states announced their conservation plan in a letter to the upper basin states—Colorado, New Mexico Utah and Wyoming. The three lower states depend on Lake Mead, the reservoir whose spigot is controlled by the U.S. Bureau of Reclamation. The cuts in the lower three states will be divided among farms, cities and tribes.

"This is a step in the right direction, although we haven’t seen the full details of the agreement yet," University of New Mexico’s water policy expert John Fleck told local media. "This is a really important agreement because the biggest water users on the Colorado River, especially California, but also Arizona, have agreed to further cut their use of water." In talking with the states, the federal government used sticks—the implicit threat of imposed usage cuts—as well as carrots. Had an agreement not been reached, the Interior Department had prepared a draft environmental impact statement that could have cut usage by as much as 2.1 million MAF. However, the government was reluctant to impose cuts that would have triggered lawsuits. The agreement is subject to an expedited review by the Department of the Interior.

The Colorado River and its tributaries pass through seven states and into Mexico, serving 40 million people and a $5 billion-a-year agricultural industry. The Upper Colorado River Basin has a drainage area of about 114,000 square miles, covering portions of Colorado, Wyoming, Utah, Arizona and New Mexico. Its water is used to irrigate about 5.5 million acres of farmland, in addition to supplying 40 million people with drinking water. Demands on its water have outstripped supply for years. Some of the country’s largest cities,

including Los Angeles, Phoenix, Denver and Las Vegas, two Mexican states, Native American tribes and others depend on the river that’s been stressed by drought and overuse. Las Vegas has grown by about 800,000 people since 2002 but has managed to cut its Colorado river usage by 31%.

The Colorado River Compact, signed in 1922, allocates Colorado River water among the signatory states, but it is due for significant revision. Scientists now know that it was signed after an unusually wet period, which led signers to overestimate the amount of water that would be available. The current agreement should buy time for the states and the federal government to work out a longer-term plan for conserving Colorado River Water.

Mexico gets 1.5 MAF under a 1944 treaty, and Native American tribes own between a quarter and a third of the allocated water rights. They are not included in the agreement but are part of the conversation.

David Murray can be reached at [email protected].