In June, the Biden administration issued what appeared to be an ultimatum to the seven states that depend on Colorado River water: agree to a voluntary plan for draconian cuts in their consumption, or the federal government will impose them unilaterally.
The request, made by Bureau of Reclamation Commissioner M. Camille Kalimlim Towton during congressional testimony, came in response to the relentless drought and overuse of water that is pushing southwestern North America toward disaster. The deadline was Monday, August 15.
And the states failed to fulfill it.
The bureau has already responded with message from the deepest interruptions ever in Colorado River water supplies from Lake Mead, the largest reservoir in the United States, and changes in the operation of Lake Powell, the second largest located upstream. The goal is to keep them – at least for now – from falling dangerously low.
Lake Mead’s light-colored “bathtub ring” of mineral deposits rises nearly 180 feet above a speedboat on June 29, 2022, near Hoover Dam. The deposits have been abandoned as the lake has dropped to record low levels due to the region’s worst megadrought in 1,200 years, plus excessive water use. (Credit: © Tom Yulsman.)
“The system is approaching a tipping point and without action we cannot protect the system,” Towton said at a news conference today.
Lake Powell is currently only 26 percent full and Lake Mead is 27 percent full – both record lows. Combined storage of major reservoirs in the upper and lower Colorado River basins is just 34 percent of capacity, down from 40 percent last year, according to latest figures from the Claims Bureau.
But even though the basin’s seven states — Colorado, Wyoming, New Mexico, Utah, Arizona, Nevada and California — missed Towton’s deadline to agree on voluntary deep cuts, her agency did not react as strongly as many water experts expected.
The bureau does declare what is known as a “Tier 2” shortage in Lower Colorado River Basin. As a result, Arizona will see a 21% reduction in the water it ultimately receives from Lake Mead in 2023. Nevada will see an 8% reduction and Mexico will see a 7% reduction. But California won’t see any cuts at all — at least not yet.
The reductions to be taken by Arizona and Nevada total 617,000 acre-feet of water. This is quite significant and is a consequence of major cuts made to Arizona’s water supply this year. However, that number doesn’t come close to what Commissioner Towton requested back in June: a basin-wide reduction of 2 million to 4 million acre-feet.
To put these numbers in perspective, consider that in all of 2021, the Upper Basin states of Colorado, Wyoming, Utah, and New Mexico used a total — for cities, farms, and industry — of about 3.5 million acre-feet.
The turquoise waters of Lake Mead, with its “bathtub ring” of mineral deposits left after the reservoir shrank, stretch north in this panoramic image taken from the upper Hoover Dam on June 29, 2022. The towers at left and right are two of the four that receive water to drive the dam’s hydroelectric turbines. There is a risk of the lake falling to what is known as a ‘dead pool’. At that point, not only would hydropower be impossible, but there would be no water flowing downstream past the Hoover Dam to consumers in Arizona and California — a real disaster. (Credit: ©Tom Yulsman)
In its announcement today, the Bureau of Reclamation touted recently passed legislation it says will help the situation. This includes the recent bipartisan Infrastructure Act, which provides $8.3 billion to address a range of issues across the country, including water and drought challenges, plus $4 billion from the Inflation Reduction Act — signed into law today by President Biden.
But it was all “kind of anticlimactic” for Jennifer Gimble, a former deputy assistant secretary for water and science at the U.S. Department of the Interior and now a senior water policy scientist at Colorado State University’s Water Center.
“It’s business as usual, but I guess we have some money to spend,” she says. “I worry that we are spending too much on initial Band-Aids and not enough on a sustainable future.”
John Entsminger, general manager of the Southern Nevada Water Authority and the state’s lead negotiator for the Colorado River, was much more blunt. Here are some of the things he said in a letter he sent to Interior Minister Deb Haaland and other officials:
“Despite the apparent urgency of the situation, the past sixty-two days have produced nothing in terms of meaningful collective action to help avert the looming crisis. . . We are at the stage where across the pool every drop counts and every single drop falls short [of the] two to four million acre feet in permanent reductions brings us one step closer to catastrophic system collapse. . .”
Back in 1983, it would probably have been nearly impossible to imagine the challenge now facing the 40 million people who depend on water in the Colorado River Basin. That year, Lake Mead swelled so much with heavy runoff that it exceeded Hoover Dam’s holding capacity. As a result, torrents of water poured into two huge spillways just upstream on either side of the dam – each designed to take roughly the equivalent of the water flowing over Niagara Falls.
When Lake Mead was last at full capacity, as seen in this photo taken in 1983, the water level reached nearly the top of the dam and almost all of the iconic four towers that serve as intakes for hydroelectric turbines were submerged. The water overflowed into two giant spillways, one of which is seen here in the foreground. (Credit: Donald Sandquist via Flickr Creative Commons)
In the late 1990s, Lake Mead came close to filling that much once again. But since 2000, southwestern North America, including the Colorado River basin, has been gripped by a drought so severe that scientists have dubbed it a “megadrought.”
Recent studies shows that it is the worst such drought in the region in at least 1,200 years. Just over 40 percent of its weight is attributed in the study to human-caused climate change, largely from warming temperatures that have caused increasing dryness. That’s why scientists call it “hot drought”.
Even in years with relatively decent snowpack in the upper basin mountains—the source of most of the river’s water—runoff is relatively low. That’s because the abnormal heat has made plants and soils so thirsty that they suck up moisture before it can flow into streams and rivers.
One of two spillways at Hoover Dam, as seen on June 28, 2022. When water levels in the lake exceed maximum capacity, the spillways take the excess and direct it into 50-foot-diameter, 600-foot-long tunnels that are angled, directing the water around the dam. Each of the concrete-lined spillways themselves is about 650 feet long, 150 feet wide, and 170 feet deep, and can handle roughly the flow of Niagara Falls. They were last used in 1983 (see previous photo). Today, spillways collect gravel instead of water. To get an idea of the scale, consider that an entire US Navy destroyer could easily fit inside this concrete structure. (Credit: ©Tom Yulsman)
Looking to the future
Warming is expected to intensify in the coming years, so much above-average mountain snowpack will likely be needed for river flows to approach what they have been. And that doesn’t seem likely. So we should expect increasing dryness.
For now, the Bureau of Reclamation is acting simply to save Lakes Mead and Powell from falling so low that the water can no longer turn the turbines in the dams that produce hydroelectric power. The bureau says it cannot allow that to happen because it would pose significant risks to dam infrastructure.
But at best, the bureau’s action today will only delay the day of reckoning.
As Jennifer Gimble says, “This just kicks the can down the road.”