Earlier this month, the federal government asked seven states that depend on the Colorado River to develop an emergency conservation agreement after the Lake Powell reservoir fell to an all-time low due to a persistent drought in the west. States were set to receive river water stored in the lake, but releasing the water would further drain the reservoir, threatening its ability to generate electricity for millions and increasing utility bills for western towns and tribes. The federal government also revealed that a drop in reservoir levels would jeopardize the pipelines that pass through the dam’s hydro turbines, potentially depriving multiple communities of drinking water and jeopardizing “public health and safety”.

Late last week, states agreed to confiscate Lake Powell’s water to ensure the reservoir can still generate electricity. The deal puts a finger on the metaphorical levee, delaying the inevitable reckoning of the Colorado River’s years-long drought — and the painful trade-off between power and water for millions. It does so in part through an unusual act of hydrological accounting.

There are two parts to this deal. The first and more immediate part is that the federal government will transfer 500,000 acre feet of water (about 162 billion gallons) from the Flaming Gorge Reservoir to Lake Powell, raising the latter’s water level. Flame Canyon, which spans Wyoming and Utah, is primarily used for water recreation, so the immediate impact of the diversion will be minimal. If the situation gets worse, the federal government could conduct more of these water transfers later this year, drawing water from other nearby reservoirs.

The second part is more complicated – and less helpful. In general, the Bureau of Reclamation discharges Lake Powell’s water into a larger reservoir called Lake Mead, which then flows to homes and farms in the Southwest. As part of the agreement, the states that depend on Mead’s water agreed to leave about 480,000 acre-feet of water in Lake Powell, lowering Mead’s water levels. (The Bureau of Reclamation had already announced earlier this year that it would delay the release of 350,000 acre-feet of water at Powell in response to spring snow runoff.)

The problem is that falling water levels in Lake Mead have had a huge impact on the water supply in the Southwest. The decline in mead has triggered mandatory water cuts in states like Nevada and Arizona, under a drought contingency plan established back in 2019. The first of these cuts came last year, when the river entered a so-called “Tier 1” shortage, reducing Arizona’s water allocation by 30 percent. This forced farmers in the Phoenix area to fallow cotton and alfalfa fields. Officials expect the river to enter a 2a or 2b shortage in the next few years, which would mean even bigger cuts. Leaving the water in Lake Powell makes it more likely that the reservoir will reach that threshold.

The deal contains a surprising workaround.In exchange for keeping the water in Lake Powell rather than letting it flow to Lake Mead, the states get something in return: Bureau of Reclamation officials will act as if the water did Go to Mead, thereby treating the water level in Mead as higher than it really is. The hope here is to avoid triggering the cuts that accompany a 2b shortage declaration, even though actual water levels in reservoirs may drop enough to warrant such cuts.

Cereals/Amelia Bates

In other words, states have agreed to make sure Lake Powell has more water than it should, and in return they can pretend that Lake Mead has more water than it really is. The agreement protects towns and tribal communities that depend on Powell for water, but for a short period of time: The ongoing drought shows no signs of abating, and it is only a matter of time before Powell’s water levels fall back into the dangerous zone, jeopardizing hydropower access and drinking water quality.

After the article was published, the Bureau of Reclamation told Grist that it had been informed of the states’ agreement and expected to make a formal decision on the matter in the coming weeks.

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Meanwhile, for the millions of people who depend on Lake Mead, the deal just delays a shortage declaration that will arrive in a few years anyway. It may give states like Arizona more time to figure out how to deal with dwindling water usage, but it won’t stop cotton fields from falling fallow or exempt suburbs like Scottsdale from the need to drastically reduce water usage.

Whenever there is a drought in Colorado, federal officials must choose between hydroelectric power for communities that depend on Lake Powell and water for communities that depend on Lake Mead. The sudden appearance of this new short-term agreement not only shows that these decisions are not going away, but that they will arrive sooner than either side on the river can imagine.

renew: This story has been updated to include Bureau of Reclamation comments received since publication.