America Built a Sea by Accident

In 1905 more than two thirds of the Colorado River turned north into a dry California basin and never came back. The Salton Sea is what it left behind. The hole that did it was cut on purpose. A bankrupt irrigation company needed a new intake before the next growing season, so in 1904 its chief engineer opened the bank of one of the largest rivers in North America, aimed it at a basin sixty metres below sea level, and installed nothing that could close it again. Record flows came in January 1905. By August the cut had widened from seventeen metres to more than ninety, water was pouring through at up to 100,000 cubic feet per second, and the new sea was rising by half a foot a day. It took the Southern Pacific Railroad two years, four dams and three weeks of rock trains dumping stone day and night to shut it. That sea should then have evaporated within fifteen years. It survived on a second accident, a century of farm drainage that nobody ever formally granted it. The 2003 Quantification Settlement Agreement moved that water toward San Diego and Coachella, mitigation deliveries ended by law on 31 December 2017, and California never built the fix it had fifteen years to build. Salinity now runs near 75 grams per litre against 35 in the Pacific. On one day in August 1999, 7.6 million tilapia died. What is emerging as the water drops is not sand. It is a century of agricultural sediment, and about 2,400 acres of it appear every year. One in five children in Imperial County has diagnosed asthma, and an October 2025 study found their lung capacity falling in step with hours of dust exposure. Beneath the southern shore sits 3.4 million tonnes of lithium that nobody has commercially extracted, and even if all of it came out, none of it would put a litre of water back. Meanwhile the beach line of the last sea that filled this basin is still visible on the Santa Rosa Mountains, thirteen metres above sea level. It has waited before. Waterwake explores the history, engineering and forgotten stories of the world's rivers, lakes, canals, dams and waterways. New documentaries regularly. Subscribe so you don't miss the next one. #SaltonSea #Documentary #Engineering #California #ColoradoRiver #ImperialValley #Geology #Geography #WaterCrisis #Lithium #History #Drought #EnvironmentalDisaster #Hydrology #Waterwake