Officials called on populations served by the river to reduce water usage starting next year.
United States officials declared the first-ever water shortage for the Colorado River, an arterial waterway that serves 40 million people in the country’s west, and called on the population it serves to reduce their usage next year.
Water levels at the largest reservoir on the Colorado River – Lake Mead – have fallen to record lows, authorities said on Monday. Water basins along the river supply household water, irrigation for farms and hydropower to Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming and parts of Mexico.
Along the perimeter of Lake Mead, a white “bathtub ring” of minerals outlines where the highwater line once stood, underscoring the acute water challenges for a region facing a growing population and drought being worsened by hotter, drier weather brought on by climate change.
States, cities, farmers and others have diversified their water sources over the years, helping soften the blow of the upcoming cuts.
However, the declaration from federal officials makes clear that conditions have intensified faster than scientists predicted in 2019 when some states in the Colorado River basin agreed to give up shares of water to maintain levels at Lake Mead.
“Like much of the [US] West, and across our connected basins, the Colorado River is facing unprecedented and accelerating challenges,” said Tanya Trujillo, an official with the federal water resources agency.
“The only way to address these challenges and climate change is to utilise the best available science and to work cooperatively across the landscapes and communities that rely on the Colorado River.”
That means, starting in January, places downstream of Lake Mead – formed in the 1930s by the building of the Hoover Dam – will receive less water.
Scorching temperatures and less melting snow in the spring have reduced the amount of water flowing from the Rocky Mountains, where the Colorado River originates before it snakes 2,330km (1,450 miles) southwest and into the Gulf of California.
According to a study released last year by the US Geological Survey (USGS), the Colorado River’s flow has declined by an average of 20 percent over the past century.
At least half of that decline can be attributed to rising temperatures in the area.
“We’re at a moment where we’re reckoning with how we continue to flourish with less water, and it’s very painful,” Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, told The Associated Press.
The declaration comes a week after the United Nations released a landmark climate report that found global temperatures were increasing faster than previously thought.
Earth’s average surface temperature is projected to hit 1.5C or 1.6C (2.7F or 2.9F) above pre-industrial levels around 2030 in all five of the greenhouse gas emissions scenarios – ranging from highly optimistic to reckless – considered by the report.
That is a full 10 years earlier than UN’s International Panel on Climate Change predicted just three years ago.