US states reach long awaited deal to rescue dwindling Colorado river

Western US states said that they reached an agreement to cut the amount of water they take from the dwindling Colorado river, which is threatened by a quarter of a century of drought and worsening climate conditions.

The plan comes after years of bitter wrangling, with states refusing to give ground even as the water course has reached crisis point, threatening drinking water supplies for 40 million people and imperiling electricity generation across the American West.

Under the proposal, the federal government will pay a reported $1.2B to water districts, Native American Tribes and cities in California, Nevada and Arizona to use less water over the next three years.

The states themselves will also cut their use, though they will not be compensated.

The reductions will reduce the amount of water taken from the once-mighty Colorado by 3 million acre-feet, or about 13 percent of all the water it supplies.

An acre-foot refers to an acre covered in water a foot deep - around 1.23 million litres or about half an Olympic-size swimming pool.

"The entire Western United States is on the frontlines of climate change - we must work together to address this crisis and the weather extremes between drought and flood," California Governor Gavin Newsom said in a release welcoming the agreement.

"California has stepped up to make significant cuts to water usage, and now, this historic partnership between California and other Lower Basin states will help maintain critical water supply for millions of Americans as we work together to ensure the long-term sustainability of the Colorado River System for decades to come."

President Joe Biden hailed the agreement as "an important step forward in our efforts to protect the stability of the Colorado River System in the face of climate change and historic drought conditions."

Deadpool

The Colorado river runs through seven US states and Mexico, supplying drinking water and hydropower and irrigating some of the country's most fertile farmland.

But what was one of the world's great rivers has now shrunk. Human-caused climate crisis means the once bountiful snowpack that feeds the river has dwindled.

What snow there is melts more quickly because of higher temperatures, and more is lost to evaporation.

Use of the river water is subject to a more than century-old agreement, made when it rained, more and fewer people depended on the waterway.

But the agreement was always something of a fiddle - a politically expedient fix that allowed users to take more water than was added every year.

For years the states and the federal government have been deadlocked on how to square this circle and equitably divvy up the shrinking supply, even as the region has become arider and river levels have dropped.

Last year Lake Powell and Lake Mead - two of the largest reservoirs in the country - fell to historic lows, with fears that they might even drop below intake pipes at the Hoover Dam, a situation known as "deadpool," which would halt hydro-electric production and stop the river flowing.

Scientists say a wet winter in the US west has alleviated some pressure on the system, but this is only a temporary reprieve as human-caused climate change continues to exacerbate a long-term drying trend in the region.