Salton Sea, California: regional study
The Salton Sea was formed when in 1905 the Colorado River burst through irrigation controls south of Yuma, Arizona, flooding the Imperial Valley in Southern California. Flooding continued for two years until a line of protective levees were built by boxcars dumping boulders from Southern Pacific tracks. By 1907, the newly named Salton Sea covered about 400 square miles and was California’s largest lake. Today Salton Sea is approximately 35 miles by 15 miles across with an average depth of 29.9 feet and 51 feet at its deepest, and over 100 miles of shoreline; it is located 228 feet below sea level
The Salton sea has no outlet, meaning the only way water escapes is through evaporation, it contains 7.3 million-acre feet of water and evaporates 1.3 million acre feet each year. But rather than evaporating away in a few years as would be expected, the sea has remained due to constant agricultural runoff from the surrounding irrigated farms. The agricultural runoff that reaches the lake often contains concentrations of DDT, selenium and mercury, which becomes concentrated as the water evaporates, causing a danger to fish and birds. Salinity is currently 25% higher than the Pacific Ocean. It is estimated that if the concentrated salt level of the Sea increases another 2%, all the fish, except the Tilapia (a salt water shrimp), will die off. Several proposal have been put forward to save the sea, the most prominent involves creating a levee to split the lake into two halves (north and south), one half would be allowed to salinate the other would be cleaned up for recreational use and as wildlife sanctuary, this solution is estimated to cost around two billion dollars and is seeking federal and state funding.