The main source of water for the sea is the Jordan River, but other smaller rivers empty into the sea also. The Jordan River empties an average of six million tons of water every twenty-four hours into the sea. Despite this and the fact that the sea has no outlet, the surface does not rise more than ten to fifteen feet. The reason for this lies in the rapid evaporation of the water because of the heat and acidness of its location below sea level.
This plus other geographical factors gives it a salt content which is approximately five times the concentration of the ocean. This makes it one of the world's saltiest. It also causes a condition where no form of marine life can live even though some fish have reportedly been found in adjacent less salty pools. The surrounding land area can support vegetation and life, however. These features of the Dead Sea plus its location in an hot and arid area inspired the biblical writers to use it as an example of a life apart from the law of God.
Bob Sheffield