FEATURE Great Salt Lake: To Be or Not To Be? Nicholas von Stackelberg and Jake Vander Laan
THE GREAT SALT LAKE (GSL) , the vast body of water that stretches north and west of the capitol city of Utah, has significant economic, ecological, and cultural importance to the region and beyond. However, it faces an array of stresses common to saline lakes throughout the world that challenge its ability to fulfill its uses and values, and threaten its very existence. Fortunately, awareness of the lake’s importance and susceptibility is increasing, and collaborative efforts are underway to protect the lake into the future. The GSL is one of the last, best open spaces proximate to the rapidly growing urban corridor where the majority of Utahns live. A place where you can witness an impossibly long vista of the Basin and Range, commiserate with birds on layover from all reaches of the hemisphere, and experience a million dollar sunset from a secluded shoreline. The strangeness of the place draws one to its unique intrigues: a lunar landscape with reddish-purple water and white-capped domes in the North Arm, open waters with just the right salinity to support a thriving brine shrimp fishery in the South Arm, and freshwater wetlands teeming with waterfowl along its eastern
strongly to a changing climate. The GSL resides entirely within one state, but its watershed extends into three states. This means the lake has been managed largely without the federal and regional resources typically associated with such a large body of water. As such, it has not received the scale of national and international attention and resources bestowed upon other critically important water- bodies such as the Great Lakes or Chesapeake Bay. The lake faces several challenges and threats that have made its future viability a growing concern. The Salt Lake City and Provo metropolitan area continues to experience high population growth, projected to push Utah’s population above 5 million by 2050. Since peaking in 1986, lake elevation has steadily declined, achieving a near-record low in 2018 (Figure 1). Historical diversions and consumptive use of water for agricultural, municipal and industrial purposes was estimated by one study to have lowered the lake 11 feet from natural levels, with proposals to increase diversions in the future. Several large-scale mineral extraction activities enhance evaporation of water. Given the lake’s large surface
shores. The intrepid visitor who ventures into the water will float weightlessly on the effervescent hypersalinity. A salinity driven density stratification results in portions of the lake being underlain by a monimolimnetic deep brine layer. There are several engineering marvels, including the Lucin Cutoff (a 102- mile railroad causeway), land-fill causeways that subdivide the lake into four distinct-yet- connected entities, the West Desert Pumping Project (which briefly created a second salt lake in the 1980s), and the Behrens Trench, a 21-mile underwater canal that ingeniously uses density gradients to convey water to evaporative ponds. The bottom of a terminal basin, GSL
Figure 1. Surface water elevations for Gilbert Bay of Great Salt Lake since 1960. The historic low lake elevation of about 4191 feet occurred in the fall of 1963. A historic high of nearly 4212 feet was subsequently observed spring of 1986. Since 1986, lake elevation has steadily declined. The lake nearly hit a new historic low in the fall of 2018. Lake elevation data from USGS NWIS database (https://waterdata.usgs.gov/nwis).
aggregates and reflects back to us the human activities within its watershed. Year over year, it sums the ledger of diversions and consumptive water use for agriculture, industry, and society. It remembers and only slowly forgets the pollutants discharged to its waters and the years of untreated sewage and industrial wastes disposed there during the pre-Clean Water Act era. The diminutive remnant of Lake Bonneville, evaporative losses from its large surface area react
area, evaporation is expected to accelerate with increased temperature under climate change. Water quality is also of concern, with the potential for increased loads of toxic compounds and nutrients.
16 | VOLUME 21 • NUMBER 5
Water Resources IMPACT
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