LAS VEGAS (KLAS) — Water officials have offered a plan to adjust Colorado River allocations among Nevada, Arizona and California to take evaporation of 1.5 million acre-feet of water into account.

It’s part of an overall plan to save 2 million acre-feet of water in the Colorado River Basin. The framework of the plan was put together by two Nevada agencies: the Southern Nevada Water Authority (SNWA) and the Colorado River Commission of Nevada (CRCNV). Another section of the plan calls for some states to save more water: Nevada water officials target Upper Basin states to save Colorado River water.

The U.S. Department of Interior is expected to act in January. The Nevada plan is the first comprehensive solution to suggest a course of action for the federal government since August, when the Bureau of Reclamation rejected state plans to save water as insufficient.

The drought contingency plan (DCP) would build in losses due to evaporation, subtracting those losses from each state’s water allocation. It’s a significant penalty for Arizona and California, which use river water for agriculture, distributing it in canals that have only recently become the focus of concern for Colorado River water states.

Upper Basin states have objected to Lower Basin states’ failure to account for water waste due to evaporation. Colorado, Utah, Wyoming and New Mexico have factored in evaporation and “transit loss” — seepage in canals — for a long time.

“This is something the federal government must do right now,” Andy Mueller, director of the Colorado River District, told Arizona Public Media in September. “They have the right to do it under the (Colorado River) Compact. They have the right to do it lawfully. They just don’t want to do it because it hurts and it’s maybe going to bring in litigation.”

Water flows along the All-American Canal on Aug. 13, 2022, near Winterhaven, Calif. The canal conveys water from the Colorado River into the Imperial Valley. (AP Photo/Gregory Bull, File)

The loss of water to evaporation accounts for more than 770,000 acre-feet each year in California and more than 400,000 acre-feet in Arizona. Nevada loses only 17,570 acre-feet to evaporation annually.

The SNWA/CRCNV plan would also address more than 350,000 acre-feet lost each year to evaporation in Mexico’s share of the Colorado River.

Together, losses add up to more than 1.5 million acre-feet.

The plan proposed by the Nevada agencies:


In the spring of 2022, the Bureau of Reclamation crafted an agreement to keep more water in Lake Powell. Lower levels were causing concern about the ability to generate power at Glen Canyon Dam. It was a practical move, with plenty of water in Lake Mead to meet contractual demands.

The result was lower levels at Lake Mead, which amplified concerns in Nevada, California and Arizona, which rely on water supplies from Lake Mead. And it came at a time when water forecasts were changing rapidly after a dry year. Both Lake Mead and Lake Powell have fallen to about 25% capacity. It didn’t buy a lot of time for power concerns at Glen Canyon.

Visitors view the dramatic bend in the Colorado River at the popular Horseshoe Bend in Glen Canyon National Recreation Area, in Page, Ariz., in 2011. (AP Photo/Ross D. Franklin, File)

When the Utah Rivers Council presented information in early August that Glen Canyon Dam’s “antique plumbing” was going to be a problem for everyone downstream, it prompted heightened discussion about whether the government could solve it.

The SNWA/CRCNV plan makes it clear that Nevada falls on the side of continuing to produce power at Glen Canyon. In the short term, that means maintaining water levels high enough to feed the turbines. In reality, it’s a commitment to more than power production. The dam’s pipes that release water downstream also rely on those higher levels. Reducing the level in Lake Powell would actually harm the dam’s ability to deliver water downstream.

CRCNV also pointed out the critical importance of power generation to communities and the Western U.S. electric grid. Power generated at Glen Canyon and Hoover Dam has played an important part in relieving recent rolling blackouts in California.


The plan also sets priorities for management of Lake Powell and Lake Mead moving forward, identifying three “operational objectives:”

  1. Ensure water can be released from Glen Canyon Dam. The agencies see this as crucial to Lower Basin water supply and the predictability of that supply.
  2. Guarantees that water “banked” in Lake Mead will be delivered when needed. In the past, Lower Basin states have “saved” water in Lake Mead when they didn’t use their full allocation. States are counting on those “water debts” being paid when needed.
  3. Protection of water supply for public health, safety and welfare. Several factors play into this priority — the most important of which is the water supply for 40 million people in the desert Southwest. By prioritizing that water supply, agriculture would be less important. Electric production is another aspect of priorities for public health.

Overall, the SNWA/CRCNV plan suggests a way to save 2 million acre-feet of water and offers some guidance to the federal government. What the government decides will determine the course of action in what could be a tumultuous year in water politics.