Why the salton sea is so salty?

Answer 1

Up until about 1900, the area was usually a dry, salty (because it had been part of a former inland salt sea that dried up) basin, with an intermittent lake that formed under heavy rain conditions. It was called the Salton Sink, and there were salt mines there.

In 1900, people attempting to develop agriculture in the area built the Imperial Canal to divert water from the Colorado River to the Salton Sink to be used for irrigation. However, the Imperial Canal soon filled up with silt.

In 1905, unusually heavy rainfall caused the Colorado River to swell, and it breached its banks (it had a little help from the company trying to reopen the canal) and began to flow into the Salton Sink. Over the course of the next few years, the Southern Pacific Railroad company attempted to stop this by dumping dirt into the river, but until the flood was finally halted, at times the entire flow of the Colorado was pouring into the Salton Sink, resulting in the creation of a large lake (the Salton Sea).

The Salton Sea has no natural outlets. It lies at a lower elevation than the surrounding land, so water flows in but is only removed by evaporation. This concentrates the dissolved salts (already pretty high because there was a lot of salt in the ground). This is basically what happens with other salt lakes (Great Salt Lake in Utah and the Dead Sea, for example), except that in this case we can point to a specific date the Salton Sea was formed.

Answer 2

It was originally a freshwater lake, but is now a saline lake, so yes, it is salty.