Saltier Than the Pacific, California’s Inland Sea’s Salinity Increases by About 1% Per Year

Deep in the desert of southern California sits one of the worst environmental sites in America, a former tourist destination that has turned into a toxic soup: the Salton Sea. The sea is one of the most unique bodies of water on earth.

Located directly on the San Andreas Fault, the Sea was created by a flood in 1905 in which water from the Colorado River flowed into the area. While it varies in dimensions and area with fluctuations in agricultural runoff and rainfall, the Salton Sea averages 15 mi (24 km) by 35 mi (56 km). It is the largest lake in California.

The lake’s salinity, about 44 g/L, is greater than that of the waters of the Pacific Ocean (35 g/L), but less than that of the Great Salt Lake (which ranges from 50 to 270 g/L). The concentration increases by about 1 percent annually.^[1]

The sea was born by accident 100 years ago when the Colorado River breached an irrigation canal.  Then,  for the next two years the entire volume of the river flowed into the Salton Sink, one of the lowest places on Earth. The new lake became a major tourist attraction, with resort towns springing up along its shores. Yet with no outflow, and with agricultural runoff serving as its only inflow, the sea’s waters grew increasingly toxic. Farm chemicals and ever-increasing salinity caused massive fish and bird die-offs. Use of the sea for recreational activities plummeted, and by the 1980s its tourist towns were all but abandoned.

The skeletons of abandoned structures are still there; ghost towns encrusted in salt. California officials acknowledge that if billions of dollars are not spent to save it, the sea could shrink another 60 percent in the next 20 years, exposing soil contaminated with arsenic and other cancerous chemicals to strong winds. Should that dust become airborne, it would blow across much of southern California, creating an environmental calamity.

In the picture below, dead tilapia float in the Salton Sea near Salton Sea Beach, California, in January 2011. Erosion and high toxicity levels from farm runoff has left the Salton Sea increasingly contaminated, causing massive fish die-offs, and lake-side towns to become all but deserted.