California offers to use less water from Colorado River as drought grips western US

Severe drought and the climate crisis have created the driest conditions in the southwest US for at least 1,200 years

As a decades-long drought has wreaked havoc on water supplies in the western United States, many states have had to face hard choices about how to keep the taps flowing.

This drought — along with heavy water use — has also decimated the Colorado River, one of the country’s iconic waterways and a lifeline for many in the desert Southwest.

Now, California is offering to reduce the state’s water use from the Colorado starting next year to help combat this crisis. But some experts have said these cuts are just one small step toward what’s needed to conserve water in the western US over the coming years.

“It’s meaningful, but it won’t get us over the finish line at all,” Sarah Porter, a water expert at Arizona State University, told CNN.

A group of California water agencies — the organisations that supply the state with water — wrote a letter to federal officials on Wednesday offering to conserve an extra 400,000 acre-feet of water per year from their Colorado River take, starting next year and through 2026.

For reference, 400,000 acre-feet of water could fill up the Great Pyramid of Giza about 200 times.

“This water, which would otherwise be used by California’s communities and farms, will meaningfully contribute to stabilizing the Colorado River reservoir system,” the agencies wrote.

Currently, California is allowed to take about 4.4 million acre-feet of water from the Colorado River system, reports the Associated Press, making this cut about 9 per cent of the state’s take from the river.

The cuts will likely impact the Imperial Irrigation District, which relies on Colorado River water more than any other district in California, and which has said it will contribute up to 250,000 acre-feet of the cuts, the AP reports.

These cuts are likely going to rely on water agencies getting some of the $4bn allocated for drought relief projects in the recently passed Inflation Reduction Act signed by President Biden.

The agencies also specified in their letter that these cuts are contingent on federal action to stabilize the Salton Sea, a rapidly shrinking lake in the southeast corner of California.

But California gets water from sources other than the Colorado River as well, notably from snowmelt runoff out of the Sierra Nevada mountains. And other western states are likely going to have to step in to achieve conservation goals.

“It’s going to need to come from everyone, certainly more from California, Arizona, Nevada, Upper Basin, Mexico, municipal water users, agricultural water users,” Chris Kuzdas, with the non-profit Environmental Defense Fund, told The Hill.

Western states that rely on the Colorado River are currently attempting to negotiate a new agreement on water use that reflects current drought conditions, but haven’t yet made clear progress, CNN reports.

In August, the US Department of the Interior announced that Lake Mead — the country’s largest reservoir, which sits on the Colorado River between Nevada and Arizona — would start operating at a Tier 2 shortage condition in 2023 as the lake reached record low water levels due to the drought.

This move means Nevada will have to cut their water use from the river by about eight per cent and Arizona by about 21 per cent next year. Mexico will also have to make cuts, approximately seven per cent of the country’s allocation from the river.

Southwestern North America is currently in the grips of a decades-long megadrought fuelled by the climate crisis that has decimated water supplies. One recent study found that the past two decades have been the driest in that region for at least 1,200 years.