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Great Salt Lake Elevations
The United States Geological Survey (USGS) has been collecting water-surface-elevation data from Great Salt Lake since 1875 and continuously since October 1902. The north part of the lake has been monitored since April 1966.
In July 2021, the southern portion of the Great Salt Lake reached a new historic low, with average daily water levels dropping about an inch below the previous record set in 1963, according to U.S. Geological Survey information collected at the SaltAir gage.
Get current and historical lake levels.
Read more about the new historic low in July 2021.
Great Salt Lake differs in elevation between the south and north parts. The Union Pacific Railroad causeway divides the lake into two parts. The water-surface elevation of the south part of the lake is usually higher than that of the north part because most of the inflow to the lake is in the south part.
Therefore, two gages are used to monitor the different lake levels. The gage at the boat harbor at Saltair Beach State Park measures the elevation of the water in the south part. It has been operated since October 1938. The gage at the Little Valley Boat Harbor, northwest of Saline, Utah meaures the elevation of the water in the north part. It has been operated since April 1966. A third gage was operated at Promontory Point (north end of the south part) from October 1986 to September 1999.
These gages record the elevation of the lake every 15 minutes and the data are transmitted to a satellite every 4 hours. These data are captured by a satellite downlink and entered into the USGS computer system. Mean daily elevations are computed and made available to the public. Wind and seiche effects may cause substantial short-term changes in elevations, which are not shown in the mean daily values.
Note: Discrepancies in the lake elevations led to revisions of the base datum and the water-level record from April 16, 1984, to April 30, 2001. The Great Salt Lake Datum Correction has a detailed explanation of these corrections.
Elevation area-volume curve for Great Salt Lake
Great Salt Lake is located on a shallow playa. Consequently, small changes in the water-surface elevation result in large changes in the surface area of the lake. This is particularly evident when the lake spills into the west desert at an elevation of about 4215 feet, greatly increasing its area.
At the historic average (1847-1986) surface elevation of 4,200 feet the lake covers an area of about 1,700 square miles. At the historic low elevation of 4,191.35 in 1963, the lake covered only 950 square miles. The drop of about 8.5 feet in elevation resulted in a loss of about 44 percent in surface area.
At historic highs during 1986 and again in 1987, the lake reached an elevation of 4,211.6 feet and had a surface area of about 3,300 square miles. The relation between water-surface elevation and corresponding surface area and volume of the lake is shown on an elevation-area-volume curve, also called a hypsographic curve (from the Greek, hypsos, meaning height).
The hypsographic curve shown below can be used to determine area and total volume of Great Salt Lake (Gilbert and Gunnison Bays) by using the water-surface elevation from the Saltair Boat Harbor USGS gage located at the south end of Gilbert Bay. The data include diked areas for salt extraction located at the south end of Gilbert Bay.
(Includes ponds at Magnesium Corporation of America)