‘Mega-drought’ threatens water and electricity supplies for millions of people in the United States

The ‘mega-drought’ in the southwestern United States has driven water levels in the two largest reservoirs to record highs, forcing unprecedented government intervention to protect water supplies and electricity in seven states.

Millions of Americans already facing critical water shortages now face the prospect of power outages as demand for energy increases during heat waves, just as hydroelectric power supplies are cut short. tough test. A U.S. electricity regulator warned this week that much of the U.S. is at risk of blackouts, in part due to drought conditions that are reducing hydroelectric supply.

US government climatologists said more than half the country was experiencing drought conditions, while a separate study estimated that the drought affecting the southwestern states was the worst to hit the region in 1,200 years. after being exacerbated by human activity.

“This is by far the worst drought on our record,” said Andrew Hoell, a drought scientist with the US government’s National Oceanic and Atmospheric Administration (Noaa). “Why wouldn’t you care about the worst drought in over a millennium? We have to live this.

Water levels in Lake Mead, the largest US reservoir, and Lake Powell upstream of the Colorado River have fallen sharply, prompting federal authorities to activate a drought emergency plan. Lake Powell’s water levels are at their lowest since it was filled in the 1960s.

With Lake Powell threatening to fall below the minimum level required to operate the Glen Canyon Dam, the hydropower of about 5.8 million homes in seven states is at risk.

US officials plan to divert water to Lake Powell from another upstream reservoir in Utah and release less water than usual downstream from Lake Mead. The stocks would “sustain” Lake Powell for about 12 months.

“We’ve never taken this step before in the Colorado River Basin,” said Tanya Trujillo, an Interior Department official, referring to emergency measures.

Jason Smerdon, a Columbia University climatologist, described “frightening” drought conditions in the southwestern states.

“All emissions scenarios suggest increased warming in the southwest and therefore increased drying,” he said. Although the drought can partly be explained by natural variability in rainfall patterns, he explained, it has been compounded by a long-term trend of aridity caused by human activity.

Noaa’s Hoell, a meteorologist who has tracked extreme weather and its relationship to climate change in annual studies, said: “The drought we are experiencing now has a high probability of reoccurring in the future.

Bart Miller, program director at Western Resource Advocates, a climate conservation group, estimated that 14 million Americans depend on the Colorado River for their water, while about 5 million acres of farmland is irrigated with l help of its waters. “More and more people are beginning to understand that the path we are on is precarious,” he said.

Neighboring states of Nevada, Arizona and California have all stepped up efforts to limit water use. Restrictions have been introduced in Nevada’s largest city, Las Vegas, including restrictions on the size of golf courses in an effort to reduce the amount of grass that needs to be watered. Farmers in parts of Arizona have also been cut off from water they can use for irrigation.

In California, Governor Gavin Newsom launched a $100 million ad campaign calling for water conservation. But when he asked residents in March to reduce their water use by 15% from 2020 levels, consumption statewide instead increased by nearly 20%.

Kate Poole, senior director of the water division at the Natural Resources Defense Council, advised further measures to conserve water supplies, including reducing the amounts used in homes and urban areas, encouraging a efficient agricultural irrigation and by recycling and reusing water.

“We face a future with much less water and higher demand due to higher temperatures,” she said.

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Rosemary C. Kearney