The Great Salt Lake is losing water at an alarming rate of four inches per year, and saving it will likely require significant reductions in water used to irrigate livestock feed crops, according to new research published in Environmental Challenges. The study found that nearly two-thirds of river water bound for the lake is being diverted for human use, with agricultural irrigation claiming the lion’s share.
Over the past three decades, the lake has lost more than 15 billion cubic yards of water. While recent above-average snowfall has temporarily masked the long-term decline, researchers say more dramatic conservation measures are needed to prevent further deterioration of this crucial ecosystem.
“The research highlights the alarming role of water consumption for feeding livestock in driving the lake’s rapid depletion,” says William Ripple, distinguished professor of ecology at Oregon State University and study co-author. The study found that 80% of agricultural water use goes to irrigating alfalfa and hay crops for cattle.
The lake’s shrinkage threatens both environmental and economic interests. As the largest saline lake in the Western Hemisphere, it supports more than 10 million migratory birds and directly generates $2.5 billion in annual economic activity through recreation, mining, and brine shrimp harvesting. The lake is also the world’s largest supplier of brine shrimp eggs, which are crucial for global aquaculture.
The researchers propose reducing human water consumption in the watershed by 35% to stabilize and begin refilling the lake. This would require significant changes to agricultural practices, including reducing irrigated alfalfa production and fallowing much of the region’s grass hay fields.
The study suggests that farmers and ranchers could be compensated for lost income, with costs ranging from $29 to $124 per Utah resident annually. This compensation recognizes the significant cultural and economic impact on farming communities, as the proposed changes could affect up to 20,000 farmers and ranchers in the basin.
“The economic and cultural adjustments required are significant but not insurmountable,” Ripple notes. “With the right policies and public support, we can secure a sustainable future for the Great Salt Lake and set a precedent for addressing water scarcity globally.”
Public health concerns add urgency to the situation. As the lake shrinks, exposed lakebed releases dust containing fine particulate matter and toxic heavy metals, residues of the region’s mining and industrial history. This poses respiratory risks to the surrounding population.
The research team analyzed water budget data from 1989 through 2022, finding that water consumption and evaporation exceeded inputs from river flows and precipitation by about 500 million cubic yards annually. While the lake has experienced natural fluctuations, human water use and climate change have pushed its water budget into an unsustainable deficit.
Notably, the study found that revenues from irrigated alfalfa and grass hay production account for less than 0.1% of Utah’s gross domestic product, suggesting that economic impacts of reduced irrigation might be manageable at a state level, though locally significant for farming communities.