Great Salt Lake formed following the evaporation of the enormous Ice Age-Lake Bonneville. Fresh water flows into the lake from the Bear, Weber and Jordan rivers.
The water in the Great Salt Lake has no outlet, so once there it evaporates and leaves behind minerals and salt, which is why the lake is one of the saltiest in the world. How salty? Depending on the location, it is two to nine times more briny than the ocean.
The Great Salt Lake is vast and shallow: 75 miles long and 35 miles wide at its widest point. Its average depth is 14 feet. It’s deepest point is 34 feet.
The economic value of the lake from mineral extraction, brine shrimp cyst production and recreation is $1.32 billion/year.
The lake's shores and food web provide sustenance, rest and nesting grounds for up to 10 million birds a year, making it one of the world’s most important migratory stopovers.
The Great Salt Lake has dropped to the lowest level on record, to an elevation of 4,190 feet. Its volume and area has shrunk by about 50 percent. It needs 8 to 15 more vertical feet of water—the equivalent of two Bear Lakes—to be healthy.
To get back to healthy state, flows to the lake would have to increase by 29% a year. At the same time, Utah is one of the fastest growing states and has the second highest per capita water use in the country. Climate change is projected to reduce runoff in the Great Salt Lake basin and increase lake evaporation.
The lake level changes naturally from fluctuations in precipitation and streamflows, but those natural changes can’t account for the recent loss of 40 percent of flow to the lake, say Utah State University researchers, who found the lake would be 11 feet higher without human consumption since the Mormon Pioneer era. The bulk of the water (63%) has gone to agriculture.
Sources: Friends of the Great Salt Lake, The Nature Conservancy, Utah State University research, Great Salt Lake Institute
