The Shrinking Great Salt Lake

October 29, 2020


Photographer: Ray Boren
Summary Author: Ray Boren

As with other closed-basin endorheic, or terminal, lakes around the world — often in arid or semi-arid climates, from Africa’s Lake Chad to central Asia’s Aral Sea — North America’s Great Salt Lake is out of balance and shrinking in size and storage. This is due in part to climate change but more particularly, hydrologists and other researchers say, because of human damming and upstream diversion of its water sources for agriculture and urban uses.

One result, as shown in this photograph, looking west from near the top of Utah’s Wasatch Range on July 26, 2020, is a depleted Farmington Bay. The lagoons in the middle of the picture are primarily diked fresh-water impoundments of Utah’s Farmington Bay Waterfowl Management Area, a key habitat for migrating and nesting birds. Otherwise, a small and sinuous river of lake water winds through the desiccated eastern lake bed and mudflats toward Antelope Island, the lake’s largest isle and a state park. Deeper water is visible beyond the island in Great Salt Lake’s central Gilbert Bay.

According to the US Geological Survey, the average surface elevation above sea level of Great Salt Lake — itself a remnant of the Pleistocene’s much larger Lake Bonneville — is 4,200 ft (1,280 m), at which point it covers about 1,700 sq mi (4,403 sq km). In the mid-1980s, as a result of several years with above-average precipitation, the lake elevation surged to 4,211.6 ft (1,283.7 m), with a much-expanded surface area of 3,300 sq mi (8,547 sq km). It was at its lowest historic surface elevation in 1963, when it dipped to 4,191 ft (1277.4 m) and covered only 950 sq mi (2,460.5 sq km) — a status Great Salt Lake has again approached in recent years. In September 2020, the USGS recorded the lake surface elevation at 4,193 ft (1,278 m) above sea level. In addition, the National Oceanic and Atmospheric Administration reported this summer that 68 percent of the Western United States, including Utah, is again in drought.

Photo Details: Camera NIKON D3200; Exposure Time 0.0020s (1/500); Aperture ƒ/11.0; ISO equivalent 360; Focal Length (35mm) 105.