The latest megadrought alarm bell just went off in the West. The Bureau of Reclamation began emergency water releases from reservoirs upstream in the Colorado River this week in an effort to keep Lake Powell, the country’s second-largest reservoir, full enough to continue to generate hydroelectric power.
The manmade lake, which sits along the crucial Colorado River, has reached the lowest levels it’s been in decades due to extreme heat and the searing drought that’s gripped the region coupled with overuse. The reservoir is projected to hit a critical new low of 1,075 metres by April 2022, just 7.6 metres above the level at which hydropower can no longer be generated. The Bureau of Reclamation said the emergency releases from reservoirs upstream — which includes the Flaming Gorge Reservoir in Wyoming, the Blue Mesa Reservoir in Colorado, and the Navajo Reservoir in New Mexico — will continue until December and could last into next year.
The low water levels in Lake Powell aren’t just a problem for the industries and cities that rely on the water in the reservoir. It’s also an issue for the Glen Canyon Dam, a 1,320-megawatt hydroelectric power plant that produces electricity distributed to customers in seven different states. The Bureau of Reclamation said the releases from Flaming Gorge, which will start this month, will increase the water level 1.4 cubic metres per second every day, and will last until July 23.
Glen Canyon Dam isn’t the only hydropower plant facing trouble with the West’s megadrought. The water level at Lake Oroville, California’s largest reservoir, has dipped so low this summer during the state’s searing heat that officials say they may have to shut off the hydropower plant there.
“We are facing unprecedented dry conditions in the Colorado River Basin, Rebecca Mitchell, Upper Colorado River Commissioner for the state of Colorado, told KUNC. “More details about conditions as well as planning efforts are forthcoming. What we do know is that the Upper Basin Drought Contingency Plan calls for increased coordination and planning in situations like this. And those agreements call for the Bureau of Reclamation to closely consult with the Upper Basin States, including Colorado. It has never been more critical to work together.”
Releasing water from upstream reservoirs during a megadrought is a big deal; as a source told KUNC reporter Luke Runyon, “Reclamation just pulled the emergency lever.” The Colorado River provides drinking water for 40 million people in states across the Southwest. Lake Powell was constructed in the early 1960s, in order to create a reservoir of supply for states along the upper part of the river to deliver water to states in the lower part of the river, as part of the 100-year-old water agreement that dictates how the river’s water is distributed.
But historic overuse of the river’s resources paired with climate change — which, studies have shown, could decrease flow by as much as 30% by 2050 — has meant that the river’s flow is rapidly diminishing.
The water levels in Lake Powell don’t just affect hydropower, but also how water is distributed throughout the Southwest. Lake Mead, another large reservoir downstream on the river, fell to its lowest levels in history in June. Officials are planning to declare water shortage conditions in August that would trigger water-saving measures in surrounding states. If Lake Powell falls below that crucial threshold of 1,074 metres that it’s set to meet next spring, it could affect how the lower states get their water — and trigger potential lawsuits and fights over who has the right to use water from the river.
In 2019, the seven states that rely on the river entered into a contingency plan for what happens if Lake Powell drops below the threshold. Part of the extreme scenario of this plan was emergency releases from upstream reservoirs, like the type of releases the Bureau of Reclamation has decided to do this month.
If the water levels fall below 1,074 metres in Lake Powell and the agreement falls apart, it could “potentially lead to seven-state litigation, which we’ve never seen before on [the] Colorado River,” Amy Ostdiek, deputy section chief of the federal, interstate and water information section of the Colorado Water Conservation Board, told Colorado Public Radio. “Which would create a lot of uncertainty. It would probably be a very long, drawn out process.”
Elsewhere, the West’s reservoirs have come under increasing pressure. Satellite imagery shows many in decline year over year. Drinking water quality is suffering, and at least one town has committed to a moratorium on new construction as water resources run dangerously low. Even natural bodies of water such as Utah’s Great Salt Lake haven’t escaped from the megadrought, also dipping to record lows.