Utah Lake is a freshwater lake in the U.S. state of Utah. It lies in Utah Valley, surrounded by the Provo-Orem metropolitan area. The lake's only river outlet, the Jordan River, is a tributary of the Great Salt Lake. Evaporation accounts for 42% of the outflow of the lake, which leaves the lake slightly saline. The elevation of the lake is legally at 4,489 feet (1,368 m) above sea level. If the lake elevation goes any higher, the pumps and gates on the Jordan River are left open.

The first European to see Utah Lake was Father Silvestre Vélez de Escalante in 1776. He stayed with the Timpanogots band of Ute Tribe for three days. The Timpanogots were later moved out or integrated with the Mormon settlers between the 1850s and 1870s. The fish of the lake were overharvested by the settlers and restocked with non-native species.

Although thirteen species of fish are native to the lake, only the Utah sucker and the critically endangered June sucker remain. The dominant species in the lake is the common carp, introduced in 1883 as an alternative to the over harvested native fish. The carp is now estimated at 90% of the biomass of the lake and is contributing to a decline in native fish populations by severely altering the ecosystem. Pollution has also caused problems with the lake's ecosystem. Raw sewage was dumped into the lake as late as 1967. Pollution problems still remain; the lake's phosphorus and mineral salt levels are in violation of the Clean Water Act.

en.wikipedia.org/wiki/Utah_Lake