Great Salt Lake supports a rich and dynamic biological system of regional, national, and global importance. The amazing abundance of bird life at Great Salt Lake has earned its designation as a Western Hemisphere Shorebird Reserve Network site (1991). Birds of regional, national, and international significance are drawn to its 1,700 square miles of various water environments, remote islands, and shorelines, and about 360,000 acres of wetlands. Every year ten million birds from 338 different species rely on the Lake to feast during their thousand mile or more migrations. While there, they enjoy a unique and safe sanctuary that supports numerous breeding populations. Great Salt Lake's ecology is an extraordinary example of the rich web of relationships between land and water, food and survival.
Great Salt Lake is a terminal lake with no outlet. Over time lake levels and salinity change dramatically depending on the quantity and quality of freshwater inputs from the Bear, Weber/Ogden, and Jordan River systems in tandem with seasonal evaporation rates. The geography of the Lake combined with man-made causeways, create a diversity of lake environments varying from the extremely salty North Arm (about 28%), to the nearly freshwater Farmington Bay. Such diverse water environments are connected to expansive playas, shorelines and uplands to create excellent habitats for innumerable plants, invertebrates, reptiles, amphibians, mammals, and birds.
This animation captures the changing elevations of Great Salt Lake over a period of 46 years (1972-2018). During this time, the Lake’s elevation fluctuated from a 12 foot increase (1972-1986) to a 17.1 foot decrease (1989-2018). Because Great Salt Lake's average depth is only 15 feet, each foot of elevation change translates into a huge difference in surface area.
In October 2021, Great Salt Lake's surface elevation dropped to 4,190.2 feet above sea level, superseding the 1963 historic low of 4,191.35 feet. In November 2022, it reached another new record low elevation of 4,188.5 feet above sea level.
As water levels decline, the Lake's salinity concentrates. A healthy salinity range for Gilbert Bay (Great Salt Lake's South Arm) is between 13-15%. In 2022, Gilbert Bay reached 19% salinity, approaching the maximum threshold that brine shrimp and brine flies are able to tolerate. Both declining water levels and rising salinity threaten the Lake's food web and the millions of migratory birds who depend on this ecosystem.
A drying Great Salt Lake has local and regional consequences including increased dust, worse air quality, reduced snow, reduced Lake access, habitat loss, island bridges, more invasive plant growth, and negative economic consequences to the state. By protecting the Lake, we help our economy, environment, wildlife, and future.
Basic Lake Facts
- At an average elevation of 4,200 feet above sea level, Great Salt Lake's surface area is 1,700 square miles with a maximum depth of 33 feet. At the 2022 record low elevation of 4,188.5 feet, Great Salt Lake's surface area was approximately 888 square miles. Current Lake elevation information is available from USGS for gauges at Saltair (South Arm) and Saline (North Arm). Explore the USGS Great Salt Lake Hydromapper for more water level and salinity data.
- Water enters Great Salt Lake via direct precipitation, the Bear, Weber, and Jordan Rivers, and internal springs. The Great Salt Lake watershed is over 21,000 square miles.
- Water entering Great Salt Lake carries dissolved minerals, including salts. When the water evaporates, it leaves those minerals behind, resulting in salty water.
- The Union Pacific Railroad Causeway divides Great Salt Lake into North and South Arms with vastly different ecosystems on either side. The Lake's North Arm (Gunnison Bay) is cut off from most freshwater inflows and is about twice as salty as the South Arm. Only halophilic bacteria and archaea can survive in this hypersaline environment, and their reddish pigment can make the water appear pink.
- Salinity varies across the Lake and in response to water levels. A healthy salinity range for Gilbert Bay (Great Salt Lake's South Arm) is 13-15%, about 3-5 times saltier than an ocean. In 2022, Gilbert Bay reached 19% salinity, approaching the maximum threshold that brine shrimp and brine flies can tolerate.
- The notorious "Lake Stink" is produced by bacteria living in lakebed sediments. These bacteria play an important role in the ecosystem, breaking down and recycling nutrients like nitrogen. Much of the smell we experience is the result of human-caused nutrient loading in Farmington Bay. Water flowing into Farmington Bay contains excessive nutrients from agriculture, industry, and sewage treatment which fuel algal blooms. Decomposition of that algae in turn fuels bacterial growth and their production of hydrogen sulfide gas.
Ecology
- 10 million migratory birds visit Great Salt Lake each year to rest, refuel, and breed.
- Over 330 species visit the Lake during migrations each year.
- As many as 5 million eared grebes, at times 50 to 90% of the North American population, rely on the Lake.
- Over one-third of the world’s population of Wilson’s phalaropes rely on Great Salt Lake. Roughly 600,000 Wilson’s phalaropes visit the Lake each year, making it the largest staging concentration in the world.
- Great Salt Lake is home to the largest breeding colony of American white pelicans west of the continental divide.
- Great Salt Lake supports 80% of Utah’s valuable wetlands.
- Brine shrimp and brine flies are a critical food source that help birds build up fat reserves for migration.
Economy
- Great Salt Lake contributes $1.9 billion to Utah’s economy each year.
- The Lake's mineral extraction, recreation, and brine shrimp industries provide over 7,700 jobs.
- The Lake contributes 5-10% of Utah’s famous snow and extends ski season by 5 to 7 weeks.. The ski industry includes another 20,000 jobs and an additional $1.2 billion.
- Great Salt Lake produces all the primary magnesium in the U.S. and 14% of the world’s supply (used in beverage cans, aircraft, computers, car parts, stadium benches and more).
- Great Salt Lake leads the western hemisphere in the production of sulfate of potash (specialty fertilizer for high-value crops).
- Great Salt Lake produces 40% of the world’s brine shrimp eggs (essential to aquaculture production).
- New technologies are underway to extract lithium from the lake to power cars and cellphones.
Environment
- Water diversions and overconsumption upstream are the primary cause of the Lake's decline, accounting for 11 feet of lost elevation. Extreme drought, rising temperatures, and growing demand for water have accelerated the Lake's decline.
- Utah is the fastest-growing state in the nation. We need to use our water more efficiently to stretch the supply.
- Declining Lake levels have exposed about 800 square miles of lakebed.
- Exposed lakebed creates dust that can contain arsenic and other metals, creating a potential public health hazard.
- Dust can affect farm production and decrease property values.
- Dust also reaches the snowpack, making it melt sooner, shortening the ski season, and disrupting water supplies.
Actions Underway
The 2022 legislative session saw a record number of water conservation bills and appropriations totaling nearly $500 million, including:
- $40 million to establish a water trust that will acquire and deliver water to the Lake
- Updated water law to ensure water in Great Salt Lake is considered a beneficial use
- $250 million to install meters on secondary irrigation systems
- Increased water conservation, including the nation’s first statewide grass removal rebate program
- In an unprecedented agreement, Weber Basin Water Conservancy District and Jordan Valley Water Conservancy District sent 30,000 acre feet to the lake to help stabilize levels.
- Passed legislation that integrates land use and water planning, which will help better plan for growth and development with less water
- Cities are adopting water efficiency standards and working toward their regional conservation goals
- $70 million in grants to promote agricultural optimization
- Developing the Great Salt Lake Watershed Integrated Water Assessment and other studies
- Working with federal and state leaders on policy and funding solutions
Recommended Emergency Measures
A 2023 report by more than 30 scientists, management experts, and conservation advocates warns that the policy progress made in 2022 is not yet resulting in additional water to reverse the Lake's decline and ongoing ecosystem collapse. Without a dramatic increase in water flow to the lake in 2023 and 2024, the Lake's disappearance could cause immense damage to Utah’s public health, environment, and economy. This briefing provides background and recommends emergency measures. The choices we make over the next few months will affect our state and ecosystems throughout the West for decades to come.
Emergency measures needed to rescue Great Salt Lake from ongoing collapse
Additional Lake Fact Sheets
Utah Department of Natural Resources One-Pager
10 Myths About Great Salt Lake
Physical Features of Great Salt Lake
Biotic Features of Great Salt Lake
Great Salt Lake Level Matrix
Science-Informed Management
The Utah Division of Forestry, Fire and State Lands, part of the Utah Department of Natural Resources, has jurisdictional responsibility for managing the Lake sustainably for future generations. The system is a hotbed of potential research opportunities that can help inform effective management decisions toward that end.
What follows are examples of some of the resources that are in place to help identify research needs and fund proposals that generate valuable science and insights about the system. These serve to increase our understanding so we can work to protect Great Salt Lake.
Meetings for these standing bodies are open to the public. We encourage you to attend these meetings and share your voice. In addition to good science, good management is informed by a well-educated community.
Visit our Additional Resources page to view more organizations working with Great Salt Lake.