Lake Mead on the Colorado River has become an hourglass of shrinking water supplies. Can lower-basin states turn back the clock?
What a difference 135 feet makes Satellite images taken in 1984 and 2016 show a dramatic change in the perimeter of Lake Mead, the major Colorado River reservoir. Drag the slider near the center of the image to view the difference over time. Images by Joshua Stevens/NASA Earth Observatory, using Landsat data from the U.S. Geological Survey
Hoover dam and the reservoir it created have had one public purpose since the 1930s, when they first tamed the Colorado River. And as the Depression's engineering marvels aged into the 21st century, Lake Mead and its dam were still seen largely as the workhorses needed to send water and hydroelectricity around the Southwest.
But in the last 15 years, things have changed. Climate change and the disconnect between the river’s water supply and the amounts promised has given Lake Mead a new identity. It remains the biggest storage tank in the Southwest's plumbing system, but now it is also an hourglass. Its falling level marks the time remaining before interstate and international agreements kick in to dictate who loses water. As of this writing, the lake level stands at 1,082 feet. As the bathtub ring on the canyon walls gets larger, the time will get shorter.
Everyone wants to keep lake levels above 1,075 feet as long as possible to delay that moment. The deeper worry is that the level will sink to 1,025 feet, at which point the federal Bureau of Reclamation would step and make decisions without any standing agreements, and a tangle of litigation would likely begin. So they are debating over how much water to store, how and by whom. Meanwhile, Mexican negotiators seem ready to agree to the plans, if the Americans can reach agreement among themselves.
The bottom line for both the lower basin negotiations and those with Mexico is the same: sharing the shortage caused by what the parties like to call a “structural deficit” – Lake Mead gets 8.23 million acre-feet from upstream releases each year, and is obliged to provide 9.1 million acre-feet to its users.
International relations are framed predominantly by 1944 treaty guaranteeing Mexico 1.5 million acre-feet of water a year. But the 73 years since that treaty have been marked by amendments – known as “minutes” – fine-tuning the agreement in terms of new developments. In the United States, current negotiations among California, Nevada and Arizona aim to produce a Drought Contingency Plan, with all users agreeing to help keep water in Lake Mead, given the risk of having its level drop below 1,075 feet or, worse, below 1,025 feet feet, when the federal Bureau of Reclamation would take over management and water allocation.
As William Hasencamp, the manager of Colorado River Resources for the Metropolitan Water District of Southern California (known as Met and one of five California subcontractors with rights to Colorado River water) describes it, the contingency plan “was not to solve problems on Colorado River – it was to buy time … There was a concern [whether existing measures] were enough to stop Lake Mead from reaching critically low levels. So they said, ‘let’s have an overlay to get us through the crisis.’” Or avoid it entirely.
While the prolonged western drought is largely over, Lake Mead's ongoing “structural deficit” means that its water level may continue to decline in the future. Should the reservoir's level drop to the levels shown below, the three lower-basin states may agree to additional reductions in their share of Colorado River water, beyond what they agreed to in 2007.
But one stumbling block after another has emerged.
In California, two users – Met and the Imperial Irrigation District (the biggest single user of Colorado water, with a claim to 3.1 million acre-feet annually) – wanted water-related demands met.
Since Met has just two pipes of incoming supply – the Colorado and northern California water coming through the Bay Delta – it wanted federal assurances that it could get one supply before it agreed to possibly curtail another. It got them, Hasencamp said earlier this month. “We still have to figure out within California about our issues. But that box with Feds has been checked.”
The Imperial Irrigation District has a different worry. The children of Imperial County in southeastern California have some of the country’s worst asthma rates. Toxic dust that blows into their lungs from the dry lakebed of the fast-receding Salton Sea. This lake, accidentally created 112 years ago when a raging river broke through dikes and poured into an inland basin, is drying out, leaving dead fish and dangerous silt behind.
Kevin Kelley, the district’s general manager, said, “we had a precondition to even signing on in that we needed some sort of coherent plan for the Salton Sea.” In March, California unveiled a new $383 million plan to build ponds and wetlands, but the funding source remains unclear. Asked if his condition for agreeing to Colorado River drought planning had been met, Kelley said, “This constitutes real progress, but we are not yet ready to declare victory.”
Met and IID had demands. But they, along with other users, felt overwhelming pressure to conserve water. A preliminary 2014 Memorandum of Understanding among the lower basin states “was an important first step to demonstrate that we in the lower basin can work cooperatively on a voluntary basis,” said Chuck Collum, the Colorado River Programs Manager of the Central Arizona Project. With a chuckle he added his own neologisms: the conservation was “vandatory” and “voluntold.”
From 2014 to 2016, under the system of intentionally created surpluses, four big users have set aside increasingly large totals, including 143,000 acre-feet in 2016, when the level of the reservoir flirted with the the 1,075-foot level. At its current level, 80,000 acre-feet equals roughly one foot of elevation in Lake Mead.
Marcus Winter via Wikimedia Commons
As Hasencamp observed, there is an evolving attitudinal change: the early 20th-century adherence to the doctrine of prior rights is now joined by a recognition that all Colorado River jurisdictions need to work together. He said this represents “progress toward seeing the larger picture.”
But in Arizona at the moment, cooperation has grown threadbare, perhaps because of the new respite from the drought. Whether thanks to a wetter winter to or more conservation, Lake Mead’s level is eight feet higher than a year ago.
Now there is jockeying for dominance over Arizona water policy. In two recent lawsuits, CAP claimed that it is equivalent to a governmental entity, and as such has sovereign immunity from suit. The claim, later modified, provoked a legal rebuttal and a sharp response from Tom Buschatzke, the Arizona Department of Water Resources director. “The governor and the executive branch feel it’s their prerogative to drive the water policy of the state,” he said. CAP “is impinging on that prerogative.”
He also opposed the suggestion of a board member of CAP’s companion agency that too much conservation could cause problems with deliveries to Lake Mead. Not so, Buschatzke said in his own op-ed.
The rest of the lower basin is watching. Kelley of the Imperial Irritation District said, “I hope they work it out because they are relying on California to help them. What happens between them is important to the entire river community.”
Though hiccups slow the progress toward the stopgap plan, Collum expects the agreement with Mexico on the new amendment will be concluded by the time the old amendment, Minute 319, ends on Dec. 31. He predicted a drought contingency plan will follow next year.
Then the struggle over the Colorado River’s long-term future will begin.
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