Great Salt Lake on track to disappear in 5 years, scientists warn

Without dramatic cuts to water consumption, Utah’s Great Salt Lake is on track to disappear within five years, a dire new report warns, imperiling ecosystems and exposing millions of people to toxic dust from the drying lake bed.

The report, led by researchers at Brigham Young University and published this week, found that unsustainable water use has shrunk the lake to just 37 percent of its former volume. The West’s ongoing mega-drought — a crisis made worse by climate change - has accelerated its decline to rates far faster than scientists had predicted.

But current conservation measures are critically insufficient to replace the roughly 40 billion gallons of water the lake has lost annually since 2020, the scientists said.

The report calls on Utah and nearby states to curb water consumption by a third to a half, allowing 2.5 million acre feet of water to flow from streams and rivers directly into the lake for the next couple of years. Otherwise, it said, the Great Salt Lake is headed for irreversible collapse.

“This is a crisis,” said Brigham Young University ecologist Ben Abbott, a lead author of the report. “The ecosystem is on life support, [and] we need to have this emergency intervention to make sure it doesn’t disappear.”

Scientists and officials have long recognized that water in the Great Salt Lake watershed is overallocated — more water has been guaranteed to people and businesses than falls as rain and snow each year.

Agriculture accounts for more than 70 percent of the state’s water use — much of it going to grow hay and alfalfa to feed livestock. Another 9 percent is taken up by mineral extraction. Cities use another 9 percent to run power plants and irrigate lawns.

There are so many claims on the state’s rivers and streams that, by the time they reach the Great Salt Lake, there’s very little water left.

Over the last three years, the report says, the lake has received less than a third of its normal stream flow because so much water has been diverted for other purposes. In 2022, its surface sank to a record low, 10 feet below what is considered a minimum healthy level.

With less freshwater flowing in, the lake has grown so salty that it’s becoming toxic even to the native brine shrimp and flies that evolved to live there, Abbott said. This in turn endangers the 10 million birds that rely on the lake for a rest stop as they migrate across the continent each year.

The vanishing lake may short-circuit the weather system that cycles rain and snow from the lake to the mountains and back again, depriving Utah’s storied ski slopes. It threatens a billiondollar industry extracting magnesium, lithium and other critical minerals from the brine.

It has also exposed more than 800 square miles of sediments laced with arsenic, mercury and other dangerous substances, which can be picked up by wind and blown into the lungs of some 2.5 million people living near the lakeshore.

“Nanoparticles of dust have potential to cause just as much harm if they come from dry lake bed as from a tailpipe or a smokestack,” said Brian Moench, president of Utah Physicians for a Healthy Environment. He called the shrinking of the lake a “bona fide, documented, unquestionable health hazard.”

Dried-up saline lakes are hot spots for dangerous air pollution. Nearly a century after Owens Lake in southern California was drained to provide water to Los Angeles County in the 1920s, it was still the largest source of hazardous dust in the country, according to the U.S. Geological Survey. The pollution has been linked to high rates of asthma, heart and lung disease and early deaths.

Kevin Perry, an atmospheric scientist at the University of Utah who studies pollution from the receding lake, said about 90 percent of the lake bed is protected by a thin crust of salt that keeps dust from escaping. But the longer the lake remains dry, the more that crust will erode, exposing more dangerous sediments to the air.

“You see this wall of dust coming off the lake, and it reduces horizontal visibility sometimes to less than a mile,” Perry said. The impact might only last a couple hours at a time, he said, but the consequences can be profound.

Climate change, driven mostly by burning fossil fuels, has increased average temperatures in northern Utah by about 4 degrees since the early 1900s and made the region more prone to drought, the report said.