The Dead Sea is fed mainly by the Jordan River, which enters the lake from the north. Several smaller streams also enter the sea, chiefly from the east. The lake has no outlet, and the heavy inflow of fresh water is carried off solely by evaporation, which is rapid in the hot desert climate. Due to large-scale projects by Israel and Jordan to divert water from the Jordan River for irrigation and other water needs, the surface of the Dead Sea has been dropping for at least the past 50 years. Environmental groups, led by Friends of the Earth, launched a Let the Dead Sea Live campaign in 2001 to preserve the lake and its unique environmental qualities. In September 2002, Israel and Jordan agreed to construct a 320-km (199-mi) pipeline that would link the Dead Sea with the Gulf of Aqaba to slow down the process of evaporation of the lakes waters. If the shrinkage is allowed to continue, it is likely that the Dead Sea might disappear altogether by 2050.
Nearly nine times as salty as the ocean, the Dead Sea contains at a depth of 305 m (1,000 ft) some 27 percent solid substances: sodium chloride (common salt), magnesium chloride, calcium chloride, potassium chloride, magnesium bromide, and many other substances. Because of the density of solids in the water, the human body easily floats on the surface. The lake contains no life of any sort except for a few kinds of microbes; sea fish put into its waters soon die.
The Dead Sea is economically important as a source of potash, bromine, gypsum, salt, and other chemical products, which are extracted inexpensively. The shores of the Dead Sea are of growing importance as a winter health resort. The lake is closely associated with biblical history; the sites of the cities of Sodom and Gomorrah are believed to lie beneath the lake.