Las Vegas Sun

October 14, 2019

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New agreement cuts water usage further if Colorado River levels keep dropping

Lake Mead

John Locher / AP

In this July 17, 2014, photo, recreational boaters ride by a bathtub ring that delineates the high water mark at Lake Mead.

The American West has never been particularly wet, but it’s getting even drier.

The Colorado River is low. Lake Mead is low. Lake Powell is low. The white ring along the sides of giant mountain-lined reservoirs continues to grow. Since 2000, the West—including Nevada—has been in a serious drought, and affected states are scrambling to adapt.

A recent agreement between Western states—initially proposed and approved by their U.S. senators and signed into law by President Donald Trump—will attempt to tackle the dearth of water in the Colorado River by instituting further water-use restrictions.

The Colorado River Drought Contingency Plan, divided into plans for the river’s upper and lower basins, is the product of years of interstate negotiations, business transactions and political dealings. What, though, does it mean for Nevada and other Western states as a whole?

A history of agreements on top of agreements protecting the Colorado

Upper basin contributions

The Colorado River is mostly refilled by melting snowpack in the Rocky Mountains. The ultimate discharge, or amount of water in the river, can fluctuate depending on annual precipitation rates, so states are allocated a percentage of discharge, which varies each year depending on the weather. The Upper Basin plan does not require any water cutbacks.

The first major agreement allocating water from the river to the states within its basin was the Colorado River Compact, signed into law in 1922.

This agreement, among other provisions, granted the upper and lower basins 7.5 million acre-feet of water [the amount needed to cover an acre of land with a foot of water] annually, required the two basins to distribute their allocations across their states, and required the upper basin not to let the river drop below an aggregate of 75 million acre-feet for any 10-year period.

Unfortunately, this first agreement was made during an uncharacteristically wet period, so the allocations were not indicative of the Colorado’s normal flow.

New lower basin contributions

• Nevada's Colorado river allocation is 300,000 acre-feet per year. If Lake Mead drops to 1,045-1,090 feet, the state will be allocated 292,000 acre-feet. If the lake drops below 1,045 feet, the state will be allocated 290,000 acre-feet.

• Arizona's Colorado river allocation is 2.8 million acre-feet per year. If Lake Mead drops to 1,045-1,090 feet, the state will be allocated 2,608,000 acre-feet. If the lake drops below 1,045 feet, the state will be allocated 2,560,000 acre-feet.

• California's Colorado river allocation is 4.4 million acre-feet per year. If Lake Mead drops to 1,040-1,045 feet, the state will be allocated 4,200,000 acre-feet. If the lake drops to 1,035-1,040, the state will be allocated 4,150,000 acre-feet. If the lake drops to 1,030-1,035, the state will be allocated 4,100,000 acre-feet. If the lake drops below 1,030, the state will be allocated 4,050,000 acre-feet.

Other agreements began in 1928 with the authorization of construction of the Hoover Dam, and have continued from then. Allocations of water to Mexico [where the river’s mouth is], desalination efforts and allocation to each state within the basins were some of the issues tackled in those agreements. Together, the series of laws and acts create what is referred to as “the Law of the River.”

One of the more recent agreements was added in 2007, and it addressed water allocations during periods of drought. Under this agreement, Nevada’s Colorado River allocation decreases by 13,000 acre-feet a year if the level in Lake Mead drops below 1,075 feet. Arizona, with a much higher annual allocation, decreases 320,000 acre-feet in that same scenario.

Additional drought contributions to the Colorado River

States along the Colorado River basin agreed in 2007 to water “contributions”—which are essentially decreases in water allocations—during periods of drought. Despite the efforts, water levels have continued to drop. To combat this, basin states recently accepted an additional agreement (which adds to the previous) in an effort to slow the decline. Here are the most recent contribution additions:

• 51.75%: Colorado

• 23%: Utah

• 14%: Wyoming

• 11.25%: New Mexico

California has senior water rights, meaning it would be the last state to decrease allocations in drought scenarios. California’s participation in the planning process was voluntary, as no cuts would technically be required of the Golden State under the law.

Jack Schmidt, director of the Center for Colorado River Studies at Utah State, said a decline in 2000 led the states to realize they needed to act to protect the river.

“With that quick drop [in water level], all the parties involved realized they had to do something,” he said.

The upper basin states tend not to use their full allocations, which Schmidt said is one of the only reasons Lake Mead has survived the drought. Water not used in the upper basin continues to flow south.

But that’s not enough. The water level in Lake Mead is still dropping, so the new contingency plans are a Band-Aid on the 2007 agreement.

What does the new agreement mean?

Probably not much for Nevada. The state has near-perfected a range of water conservation and recycling measures that will likely cover any reductions in its allocations from the Colorado.

Projections

The federal Bureau of Reclamation’s most current projections say there’s a 69% chance that Lake Mead will drop below 1,075 feet in 2020, an 82% chance in 2021, an 81% chance in 2022 and a 79% chance in 2023. The lake is already below 1,090 feet, so additional cuts in allocations won’t come into play for a while.

The Bureau sets the likelihood that Lake Mead will drop below 1,050 feet before [and including] 2020 at 0%, and a no more than 39% likelihood by 2023.

Nevada, like the other lower basin states, has signed on to further “contributions”—essentially further water allocation cuts—to Lake Mead in the event of a low water level. The Silver State has agreed to an additional 8,000-acre-foot contribution if the water level at Lake Mead falls below 1,090 feet, and a 10,000-acre-foot contribution if Lake Mead recedes below 1,045 feet.

These contributions come on top of the previously promised allocations agreed to in 2007.

Nevada is one of the smallest contributors under the plan when measured by a straight amount of acre-feet.

For example, Arizona would contribute 192,000-240,000 under the same river levels, and California would contribute 200,000-350,000, on a sliding scale determined by the river’s water levels between 1,030-1,045 feet.

As of June 1, the Lake Mead water level was just above 1,086 feet. Nevada should be fine because it gets credit for recycled water returned to the river.

“We’re in pretty good shape,” said Eric Witkoski, executive director of the Colorado River Commission of Nevada.

The state, which gets 300,000 acre-feet a year from the Colorado, has attacked water waste vigorously. Witkoski said the Southern Nevada Water Authority targeted activities such as lawn watering and car washing to discourage any use that left water in the ground, where it cannot be recycled.

The agreement will expire in 2026, so the states will continue to hash out a more long-term solution—though Schmidt doesn’t like the word “permanent.”

“The reality is we see into the future poorly,” he said, stressing that continued changes in the climate would require continued action to protect the Colorado.

How did we get here?

The world is getting hotter.

Warming temperatures mean less snowfall on average. Less snowfall means less snowpack in the Rocky Mountains, which means that each spring there’s not enough water flowing down the mountains to feed the Colorado and the streams that empty into it.

Schmidt said the drought’s connection to climate change is “unambiguous.”

“There isn’t one serious water manager in the Colorado River basin who doesn’t take climate change seriously,” he said.

Hotter temperatures can cause more rain and less snow, higher evaporation rates and staggered snowmelt. Under the Trump administration, the United States has retreated from serious action on climate change, stepping back from the Paris Climate Agreement almost immediately after President Donald Trump was sworn into office.

Schmidt has little patience for partisan bickering around climate change. The issue, he said, it settled.

“There’s no time for silly political rhetoric,” Schmidt said. “We’ve got big decisions to make.”

This story originally appeared in the Las Vegas Weekly.