Last November, the Great Salt Lake fell to its lowest surface elevation on record, according to a report published last month. The lake had lost 73% of its water and 60% of its area, the report stated, and more than 800 square miles of lakebed sediments were laid bare .
Without emergency action to double the lake’s inflow, officials say it could dry out in five years.
“We’re seeing this system crash before our eyes,” warns Bonnie Baxter, director of the Great Salt Lake Institute at Salt Lake City’s Westminster College.
Economists estimate the lake's waters and wetlands yield thousands of jobs and an annual $2.5 billion for Utah from mineral extraction and brine shrimp eggs used worldwide as food for farmed fish and shrimp. The lake also suppresses windblown toxic dust, boosts precipitation of incoming storms through the “lake effect” and supports 80% of Utah’s wetlands.
The Great Salt Lake has no outlet. It can hold its own against evaporation only if sufficient water arrives from three river systems, fed by snowmelt in the lake’s 21,000-square-mile mountain watershed. When that flow declines, the shallow lake recedes.
In each of the past three years, the lake has received less than a third of its average streamflow, recorded since 1850. And as the lake shrinks, it grows saltier, currently measuring 19% salinity. This is six times as salty as the ocean and well past the 12% salinity that’s ideal for brine shrimp and brine flies.
More than 10 million birds depend on the lake’s tiny invertebrates for food. Half of the world’s population of Wilson’s phalaropes feasts on Great Salt Lake brine flies in summer, taking on fat reserves for their 3,400-mile, non-stop migration to South America. For phalaropes, the lake is “a lifeline,” says conservation biologist Maureen Frank.
All these wonders do best with a minimum healthy lake level of about 4,200 feet in elevation, which the Great Salt Lake hasn’t seen for 20 years.
The crisis didn't happen overnight. A build-up of dams, canals and pipelines to harness incoming water throughout the lake’s watershed began soon after 1900. With a lake this big and with natural fluctuations in weather, “unsustainable behavior doesn't get noticed until you are really far down the line,” says Ben Abbott, ecologist at Brigham Young University.
By the 1960s, diversions had bled the lake to levels nearly as low as today before a wet period masked the downward trend. In the mid-1980s, the lake hit a historic high, flooding wetlands and highways and threatening the Salt Lake City International Airport.
When precipitation dropped to normal levels, however, the lake declined again, aided by a warm climate that reduces natural flows and increases evaporation.
Agriculture is the primary driver of the disappearing lake. Two-thirds of the diversions in the Great Salt Lake watershed go to farms and ranches. With climate change accelerating, experts say the only way to bring back the lake is to decrease diversions and crank open the spigots of incoming streams.
This likely will require action from the state Legislature .
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The 2023 legislative session ends March 3. And waiting another year could bring dire consequences.
“Unlike politicians, hydrology doesn’t negotiate,” Brigham Young University scientist Ben Abbott says.
Stephen Trimble is a contributor to Writers on the Range, writersontherange.org, an independent nonprofit dedicated to spurring conversation about the West. A 35th anniversary update of his book, "The Sagebrush Ocean: A Natural History of the Great Basin," will be published next year.
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