As Lake Powell dries up, the US turns to inventive accounting for a short-term repair

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Earlier this month, as water levels in the Lake Powell reservoir fell to file lows amid the ongoing Western drought, the federal authorities requested seven states that depend on the Colorado River to work out an emergency conservation deal. The states had been scheduled to obtain river water that was saved within the lake, however releasing the water would have drained the reservoir additional, threatening its skill to generate hydroelectric energy for hundreds of thousands of individuals and elevating utility payments for cities and tribes throughout the West. The feds additionally revealed that declining reservoir ranges would endanger the tubes that carry water previous the dam’s hydropower turbine, doubtlessly depriving a number of communities of consuming water and compromising “public well being and security.”

Late final week, the states agreed to forfeit their water from Lake Powell with a purpose to make sure that the reservoir can nonetheless produce energy. The deal places a finger within the metaphorical dike, suspending an inevitable reckoning with the years-long drought that has parched the Colorado River — and a wrenching tradeoff between energy entry and water entry for hundreds of thousands. It does so, partly, by means of an uncommon act of hydrological accounting.

The deal has two elements. The primary and extra easy half is that the federal authorities will transfer 500,000 acre-feet of water (about 162 billion gallons) from the Flaming Gorge Reservoir into Lake Powell, bumping up water ranges within the latter physique. Flaming Gorge, which stretches throughout Wyoming and Utah, is generally used for water recreation, so the quick results of the switch will likely be minimal. The feds might do extra of those water transfers later within the yr if issues worsen, drawing on water from different close by reservoirs.

The second half is extra sophisticated — and fewer useful. In unusual circumstances, the Bureau of Reclamation releases water from Lake Powell into a fair bigger reservoir known as Lake Mead, from which it then flows to households and farms throughout the Southwest. As a part of the deal, the states that depend on Mead water are agreeing to go away about 480,000 acre-feet of that water in Lake Powell, thus decreasing the water ranges in Mead. (Reclamation already introduced earlier this yr that it might delay the discharge of 350,000 acre-feet of water in Powell in anticipation of spring snow runoff.)

The issue is that Lake Mead’s falling water degree has enormous implications for water entry within the Southwest. Pursuant to a drought contingency plan labored out again in 2019, declines in Mead set off necessary water reductions for states like Nevada and Arizona. The primary of those reductions arrived final yr, when the river entered a so-called “Tier 1” scarcity, leading to a 30 p.c lower to Arizona’s water allocation. This has pressured farmers within the Phoenix space to fallow their cotton and alfalfa fields. Officers anticipate the river to enter a Tier 2a or 2b scarcity within the coming years, which might imply even bigger cuts. Protecting water in Lake Powell makes it extra probably the reservoir will attain that threshold.

The deal comprises an eyebrow-raising workaround for this. In trade for leaving the water in Lake Powell relatively than having it stream to Lake Mead, the states get one thing in return: Officers on the Bureau of Reclamation will act as if that the water did go to Mead, thus treating Mead’s water degree as if it’s greater than it truly is. The hope right here is to keep away from triggering the cuts that might accompany a Tier 2b scarcity declaration, though the precise water degree within the reservoir will probably fall low sufficient to warrant such cuts.

A map of the Colorado River
Grist / Amelia Bates

In different phrases, the states have agreed to make sure Lake Powell has extra water than it ought to, and in return they get to fake as if Lake Mead has extra water than it does. The deal protects the cities and tribal communities that depend on Powell for water, however just for a short while: The continued drought has proven no indicators of letting up, and it’s solely a matter of time earlier than water ranges in Powell fall again into the hazard zone, jeopardizing hydropower entry and consuming water high quality.

After publication of this text, the Bureau of Reclamation advised Grist that it had been knowledgeable of the states’ settlement and expects to succeed in a proper choice on the matter within the coming weeks.

For the hundreds of thousands of people that depend on Lake Mead, in the meantime, the deal simply postpones a scarcity declaration that was certain to reach in a number of years anyway. It might give states like Arizona extra time to determine how to deal with declining water allotments, nevertheless it received’t cease cotton fields from going fallow or absolve suburbs like Scottsdale of the necessity to drastically scale back their water utilization. 

For so long as there’s a drought on the Colorado, federal officers must select between hydroelectric energy in communities that rely on Lake Powell and water entry in those who depend on Lake Mead. The sudden introduction of this new short-term deal reveals not solely that these choices aren’t going away, however that they may arrive quicker than any of the events on the river ever thought they might.

Replace: This story has been up to date to incorporate feedback from the Bureau of Reclamation that had been obtained after publication.

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