Fresh water is a limited resource. It is constantly renewed, but it is not unlimited. This is especially an issue in arid and semiarid areas, such as in the area of Israel and its neighbors. One of the concerns that triggered the 1967 Six Day War, in which Israel captured the Golan Heights from Syria, the West Bank from Jordan, and the Sinai Peninsula from Egypt, was the possibility that the Arabs would cut off much of Israel’s fresh water supply.
The Dead Sea itself is not only the lowest place on the surface of the Earth, it is also one of the saltiest bodies of water. Its waters are nearly saturated with magnesium chloride, potassium chloride, as well as a bit of the more familiar sodium chloride. This salty mix is what makes it the “dead” sea; nothing can live in it except a few salt-loving bacteria.
The Dead Sea is shrinking. Most maps in the back of Bibles show the shoreline as it existed in the 1950s:
Moody Bible Institute map from the back of my ESV Bible
The Dead Sea has no outlet, and its only consistent source of water is the Jordan River. The Jordan and its tributaries, however, have been diverted upstream for a variety of agricultural, industrial, and domestic uses. The result is that the Jordan is often reduced to a trickle by the time it reaches the Dead Sea. In past decades, the elevation of the surface has dropped from -395 m (-1295 ft) to -418 m (-1371), and it continues to drop at up to one meter per year. The image below, from NASA Worldwind, shows the present shoreline, with salt evaporators occupying the southern portion of the basin.
The governments of Israel, Jordan, and the Palestinian Authority have held talks on the possibility of pumping sea water from the Red Sea into the Dead Sea basin in order to stabilize the Dead Sea. This could include the generation of hydroelectric power, which could be then used to desalinize some of the sea water.
BBC News Article: Obstacles to Peace: Water
Grace and Peace