Salton Sea

The Salton Sea is a shallow, landlocked, highly saline body of water in Riverside and Imperial counties at the southern end of the U.S. state of California. It lies on the San Andreas Fault within the Salton Trough, which stretches to the Gulf of California in Mexico. Over millions of years, the Colorado River had flowed into the Imperial Valley and deposited alluvium (soil), creating fertile farmland, building up the terrain, and constantly moving its main course and river delta. For thousands of years, the river alternately flowed into the valley or diverted around it, creating either a salt lake called Lake Cahuilla or a dry desert basin, respectively. When the Colorado River flowed into the valley, the lake level depended on river flows and the balance between inflow and evaporative loss. When the river diverted around the valley, the lake dried completely, as it did around 1580. Hundreds of archaeological sites have been found in this region, indicating possibly long-term Native American villages and temporary camps. The current lake was formed from an inflow of water from the Colorado River in 1905. Beginning in 1900, an irrigation canal was dug from the Colorado River to the old Alamo River channel to provide water to the Imperial Valley for farming. The headgates and canals sustained a buildup of silt, so a series of cuts were made in the bank of the Colorado River to further increase the water flow. Water from spring floods broke through a canal head-gate diverting a portion of the river flow into the Salton Basin for two years before repairs were completed. The water in the formerly dry lake bed created the modern lake, which is about at its widest and longest. A 2023 report puts the surface area at 318 square miles (823.6 km2). During the early 20th century the lake would have dried up, except that farmers used generous amounts of Colorado River water for irrigation and let the excess flow into the lake. In the 1950s and into the 1960s, the area became a resort destination, and communities grew with hotels and vacation homes.