Salton Sea, California

The Salton Sea is a 40 mile long inland sea formed by accident, and is now a briny agricultural sink, in one of the most arid places in the country. Before the sea formed, the area was a dry depression, below sea level, south of which was one of the most productive agricultural areas in the state. In 1905, an irrigation canal that brought Colorado River water to the valley was overwhelmed by high water from rains along the Colorado watershed. The entire flow of the Colorado River drained into the Salton Sink, rapidly filling it up with water, before the breach could be dammed. For decades the sea served as a sink for the salty water washed off the fields of Imperial Valley agribusinesses. While this initially resulted in rising sea levels, recent reductions in runoff, by recycling water and sending it to thirsty San Diego, have created the opposite problem: expanding areas of exposed lakebed where the water has receded. Fish kills frequently occur when algae blooms suck up all the dissolved oxygen lining the shore with a layer of desiccating tilapia. Though now the water is too salty even for tilapia, and likely hardly any fish remain. As of 2019, without any water coming into the sea, it is evaporating at a rate of more than a foot a year, and may be developing into a toxic dust cloud source that would make Owens Lake look like a breeze in a park.