Desert Lakes

In humid environments, ground water or streams can feed into lakes, supplying water to replace what evaporates out. In the desert, however, streams are often intermittent, and ground water is usually well below the lake bed, so that lake water leaks into the ground. That means that lakes often will dry up, forming a dry lake bed called a playa. The water evaporates, but the dissolved minerals (the salts) in the water stay behind. Over time, as the lake fills and dries many times, the water can become much saltier than you expect!