The Salton Sea is the largest lake in California. It is located in the southeastern corner of the state; it spans across Riverside and Imperial counties in one of California’s most scenic desert areas. As part of the Colorado Desert ecosystem, the Sea demonstrates unique features that contribute to both its appeal and to its future.
The Sea occupies the lowest portion of a structural basin called the Salton Trough. Mountains, including the Santa Rosa Range to the west, Orocopia Mountains to the north and the Chocolate Mountains to the east, surround the closed basin. By virtue of its location, the Sea is a terminal lake, meaning that it has no outlets.
The Sea is not the first lake to occupy the Salton Basin. In fact, there have been many “Salton Seas,” dating back to the time when the Colorado River deposited enough sediment across from its prehistoric mouth at Yuma to create a berm that divided the northern Gulf of California (stretching from approximately Brawley to Indio) from the southern Gulf. The fickle Colorado changed course frequently, running sometimes north into the Salton Basin and sometimes south to what became the Mexican Delta. In the last 2000 years, at least three large lakes filled the basin for hundreds of years, with many more small lakes in between. Some scientists think the Colorado flowed into the Salton Basin more often than it flowed to the present Gulf.
When the basin filled completely, the lake that formed would be six times the size of the present Sea, stretching over 100 miles. The ancient shoreline and mollusk and other remnants can be seen around the Sea.
The current Salton Sea stretches out over a length of 35 miles along a northwest/southeast axis and spans a width of 15 miles. (See map with dimensions) Its southern half is broader than the northern half, and the Sea encompasses 376 square miles of surface area. The Sea’s current elevation is about 227 feet below mean sea level, its maximum depth is 51 feet and its total volume is about 7.5 million acre-feet (maf).
The present water level of the Sea is sustained by agricultural runoff and, to a lesser extent, by municipal effluent and storm water that flows into the Sea through rivers and creeks in the Imperial, Coachella, and Mexicali Valleys. Annual Sea inflow is 1.36 million-acre-feet per year.
Inflow comes from sources such as the Whitewater, Alamo, and New rivers, bringing with it salt from the Colorado River. The salinity level of the Sea is 44 parts per thousand (ppt) - an estimated 500 million tons of salt presently. Because its salt content causes vessels to be more buoyant, surface travel on the Sea is known to be the fastest in the nation. The concern, on the other hand, is that rising salinity levels could upset the delicate balance of biological systems at the Sea.
The Salton Sea is part of the Colorado Desert ecosystem, where annual precipitation rarely exceeds three inches. The meager rainfall supports such drought-tolerant vegetation as desert scrub, creosote bush, saltbush, and tamarisk; the area’s streams and springs, which ultimately drain into the Salton Sea, support cottonwood, willow, and other plants in freshwater marshes. The botanical landscape also includes acres of agricultural lands, with crops that owe their existence almost solely to water imported from the Colorado River to the east.
The Sea and the wetlands along its shoreline are a critical part of the Pacific Flyway (a major migratory avian corridor) providing permanent habitat and seasonal refuge to millions of birds, representing hundreds of species.
Besides fishing and bird watching, the Salton Sea offers many other opportunities for recreation and is a popular destination for those seeking the serenity of the desert and the seemingly endless vistas of water, land and sky. The Sea is so large that the distant shores are not visible in some areas due to the Earth’s curvature. The Salton Sea State Recreation Area occupies the northeast shoreline while the Sonny Bono Salton Sea National Wildlife Refuge, operated by the U.S. Fish and Wildlife Service, spans the southern shoreline.