Federal agency caps downstream cuts at 3 million acre-feet
Arizona, California and Nevada are negotiating how to divide a shrinking Colorado River as the basin’s drought enters its third decade. About 40 million people depend on the river.
The seven states using the river have not replaced a century-old agreement that expires this year. Arizona, California and Nevada draw water downstream of the dams, while Wyoming, Utah, Colorado and New Mexico take water before it reaches the lower basin.
The existing plan was written before declining snowfall and higher temperatures increased evaporation and reduced the river’s flow. The river is expected to provide about half the water that the plan budgeted for this year, and the plan’s architects also overstated the river’s flow.
The Interior Department’s Bureau of Reclamation operates the reservoirs and their hydropower generators. The bureau has set an upper limit of 3 million acre-feet on how much water it can cut from the downstream states’ entitlements in coming years.
That amount is slightly larger than the total volume assigned to Arizona under the plan. The three lower-basin states say the upper-basin states should also accept cuts, but the bureau has less control over water before it reaches its reservoirs. The dispute could end up in court as the states negotiate over supplies that are not available.
Lake Mead, the reservoir formed by Hoover Dam, had stood at 1,041 feet as of Tuesday, according to the Bureau of Reclamation. That was nearly 100 feet below its 1990-to-2020 average. The lake’s dead-pool level is 895 feet, below which water falls beneath the outlet pipes and cannot be released on demand. Water must reach 950 feet to flow into the dam’s hydropower generators.
Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, said the agreements do not align with the amount of water held in storage.
“There’s a cognitive dissonance between the intricacies of these deals and the actual amount of water that is in storage,” Porter said.
The effects of reduced supplies are expected to differ among users. Farmers use most of the river’s water and would likely face the greatest impact, according to the report described by The Wall Street Journal. Fast-growing Southwestern cities may be better positioned to find alternatives such as groundwater.
Porter said cities could make the investments needed to keep their taps running, but she expressed concern about rural communities and Native American tribes. She said the federal government could purchase some water-intensive farmland or pay farmers to leave it fallow, as it did after the Dust Bowl.
Steve Kloos, a partner at water-focused investment firm Burnt Island Ventures, has proposed what he calls Basin 2.0. His plan would expand measures already in use, including ocean-water desalination and aquifer replenishment, with federal incentives for reducing consumption.
“We can get on top of this,” Kloos said.
A recent report by a group of water-policy experts warned that another winter like the last could push Lake Mead and Lake Powell low enough to disrupt the system used to store and release water. A wetter winter could replenish the reservoirs and give the states more time to negotiate.
The report’s outlook says water consumption will fall in some form, while negotiations over how to manage the reductions remain unresolved.