The Great Salt Lake in northern Utah faces a significant environmental challenge as its water levels rapidly decline. This unique body of water is experiencing unprecedented shrinkage, threatening the region’s ecological balance and human communities.
The Lake’s Identity and Changing Levels
The Great Salt Lake is the largest saline lake in the Western Hemisphere, a remnant of ancient Lake Bonneville. As a terminal lake, it has no outflow, losing water primarily through evaporation. This concentrates its mineral content, resulting in high salinity. This distinct characteristic supports a specialized ecosystem and holds considerable ecological and economic importance for Utah.
Historically, the lake’s water levels have fluctuated, with records dating back to 1847. It reached a high of 4,211.65 feet in 1986, covering approximately 3,300 square miles. However, a sustained decline brought levels to a record low of 4,188.5 feet in November 2022. This rapid shrinkage signals a deeper underlying issue.
Key Factors Contributing to Decline
A primary reason for the Great Salt Lake’s decline is extensive water diversion from its tributary rivers. Water from the Bear, Weber, and Jordan rivers, which are the main fresh water inputs to the lake, is redirected for human use. Agriculture accounts for the largest share, consuming 64% to 80% of the diverted water in the Great Salt Lake Basin. Municipal and industrial sectors also draw water, significantly reducing the lake’s inflow. These diversions have lowered the lake’s elevation by approximately 11 feet.
Climate change exacerbates the issue through increased evaporation rates from the lake’s surface. Rising regional temperatures intensify water loss. Prolonged droughts also reduce snowpack in surrounding mountains, the primary source of the lake’s freshwater inflow. The combined effect of diminished natural water supply and increased evaporative loss leads to the lake’s shrinking volume.
Impacts of a Shrinking Lake
The diminishing size of the Great Salt Lake has far-reaching consequences, particularly for its unique ecosystem. The lake serves as a habitat for millions of migratory birds, with 7.5 to 10 million individuals from over 330 species relying on it for resting and foraging along the Pacific Flyway. The lake’s specific salinity levels are essential for brine shrimp and brine flies, which form the base of the avian food web. In 2022, the southern arm’s salinity reached 19%, approaching the upper tolerance limit for brine shrimp, whose healthy range is 13-15%. As water levels recede, islands that once provided safe nesting grounds for birds become connected to the mainland, exposing birds to predators.
The exposure of vast dry lakebed areas threatens air quality and public health. Exposed sediments contain accumulated heavy metals like arsenic, cadmium, lead, copper, mercury, and lithium, originating from industrial, agricultural, and metropolitan pollution. Wind events can lift these fine particulates into the air, creating dust storms that impact local communities. Inhaling this dust is linked to respiratory and cardiovascular ailments, posing a health risk to the population in the Wasatch Front.
Economically, the shrinking lake affects several industries. It supports a $1.3 billion to $1.9 billion annual economy, including mineral extraction (magnesium, salt), the brine shrimp industry, and recreation. The brine shrimp industry alone provides 35% to 45% of the worldwide supply of brine shrimp cysts, used as aquaculture feed. The lake also influences regional weather patterns, contributing to lake-effect snow that benefits the ski industry, generating millions in revenue. Continued decline could lead to billions in economic losses, impacting jobs and local revenue.
Current Efforts for Preservation
To address the lake’s decline, various conservation and water management strategies are being implemented. Initiatives focus on reducing overall water consumption, particularly in the agricultural sector, which is the largest water user. Promoting efficient irrigation techniques and encouraging practices like fallowing fields are key. Residential users are encouraged to reduce outdoor watering and adopt drought-tolerant landscaping.
Policy and legislative measures are underway to protect the Great Salt Lake. The Utah Legislature has enacted bills, such as H.B. 453, which reevaluates water use by mineral extraction companies and ensures conserved water reaches the lake. Other legislation, like H.B. 61, focuses on enhancing water flow measurement to track usage and conservation. The creation of a Great Salt Lake Commissioner and dedicated funding supports these efforts.
Ongoing research and monitoring contribute to understanding the lake’s dynamics and informing conservation strategies. Scientific studies track water levels, salinity, and ecological responses to changing conditions. This data is essential for developing effective long-term solutions and adapting to the lake’s evolving challenges.