The Great Salt Lake, the largest saltwater lake in the Western Hemisphere, is experiencing an environmental and economic crisis driven by rapid water loss. Located in Utah, this terminal lake has no outflow; its water balance is maintained solely by inflows offsetting evaporation. The lake is shrinking dramatically due to a combination of human water use and climatic factors. This decline threatens the region’s ecology, economy, and the health of millions of nearby residents.
The Visible Evidence of Decline
The most immediate evidence of the lake’s decline is the dramatic drop in its water elevation. The southern arm reached a historic low of 4,188.5 feet in 2022, approximately 11 feet lower than its long-term average elevation. This continuous shrinkage has exposed vast expanses of the lakebed, with estimates suggesting the lake has lost nearly 42% of its surface area in the last decade.
The newly exposed land, or playa, now covers more than 800 square miles. As the lake’s volume decreases, the remaining water becomes increasingly concentrated, leading to elevated salinity levels that stress the ecosystem. Salinity in the South Arm, which supports most of the lake’s wildlife, reached over 180 grams per liter (18%) in late 2022, exceeding the range required for the survival of foundational species.
Primary Drivers of Water Loss
The primary cause of the Great Salt Lake’s diminished state is the unsustainable diversion of water from the three major feeding rivers: the Bear, Jordan, and Weber Rivers. Human consumption accounts for an estimated 67% to 73% of the lake’s water level decline, far outweighing the effects of natural variability and climate change. This water is withdrawn upstream before it reaches the lake, significantly reducing inflow.
Agriculture is the largest consumer, accounting for approximately two-thirds of the diverted water within the Great Salt Lake Basin. This usage, predominantly for irrigating crops like alfalfa and hay, is a major factor in reducing water flowing into the lake. The municipal and industrial sectors also contribute to the water deficit, using about 25% of the diverted water, often for residential and commercial landscape irrigation.
This human-driven water deficit is compounded by climate change and prolonged drought. Increased air temperatures accelerate evaporation from the lake’s surface and the surrounding watershed. Reduced mountain snowpack, the main source of the lake’s water supply, results in lower stream flows. This combination of increased water leaving the system and decreased water entering creates a severe imbalance.
Far-Reaching Environmental and Health Consequences
The ecological stability of the Great Salt Lake is threatened by rising salinity, which jeopardizes the entire food web. The endemic brine shrimp and brine flies, which require a specific salinity range, are experiencing population declines, with signs of collapse observed in 2022. These species are the main food source for millions of migratory birds, including eared grebes, phalaropes, and avocets, that use the lake as a stopover point on the Pacific Flyway.
The primary public health concern stems from the exposed lakebed, which is rich in contaminants. The dried sediments contain heavy metals and pollutants, including arsenic, lead, copper, and mercury, accumulated from natural sources and industrial activity. When high winds sweep across the exposed playa, this fine particulate matter becomes airborne, creating dust storms that degrade air quality along the Wasatch Front, where over two million people reside.
This dust poses respiratory and long-term health risks, as the particles are small enough to be inhaled deep into the lungs. The economic fallout affects multiple sectors, including the local mineral extraction industry, which relies on the lake’s brine for harvesting salt and magnesium. Recreation and tourism suffer, as shrinking waters limit boating and impact wetland habitats surrounding the lake.
Water Management and Conservation Strategies
Addressing the decline of the Great Salt Lake requires a coordinated effort focused on conserving and dedicating water to the lake. State lawmakers have initiated policy changes and allocated funding for conservation efforts, recognizing the urgency. However, researchers suggest that current measures only represent a fraction of the conservation needed to return the lake to a stable level.
A major focus involves modernizing agricultural irrigation practices, which hold the greatest potential for water savings. High-efficiency systems, such as drip irrigation, can reduce water consumption compared to traditional methods. Legislative actions have begun to challenge the long-standing “use it or lose it” water rights doctrine, allowing users to conserve water without forfeiting their rights.
Municipal conservation measures, such as turf removal programs and restrictions on outdoor watering, are being implemented in cities along the Wasatch Front. Water companies and industrial users, including salt harvesting operations, have agreed to dedicate water rights and reduce consumption to increase flow to the lake. These actions are part of the complex challenge of balancing the water demands of a growing population with the ecological imperative of preserving the lake.