Dead Sea Level Falling Due to Water Use in Jordan and Syria, Study Finds

Decline has accelerated from 70 centimeters a year four decades ago to 1.2 meters over the past two decades.

Gil Cohen-Magen

The main reason for the rapid drop in the Dead Sea’s water level in recent decades is the increased pumping of water from the Jordan River’s tributaries in Jordan and Syria, and not the potash industries in Israel and Jordan, as previously thought, a new study has found.

The goal of the study, conducted by Nadav Lensky and Elad Dente of the Geological Survey of Israel, was to ascertain why the drop in the Dead Sea’s water level hadn’t slowed even though its surface area has shrunk by about 20 percent in recent decades. The shrinking surface raises the concentration of salt in the water, and higher salt concentrations ought to slow evaporation and therefore slow the drop in the water level. Instead, the decline has accelerated from an average of 70 centimeters a year four decades ago to 1.2 meters over the past two decades.

There were two possible explanations. One was growing use of Dead Sea water by the potash industries in Israel and Jordan. The other was a decline in the amount of water entering the sea from the Jordan River and its tributaries, some of which lie in Jordan and Syria. The researchers considered the possibility that the amount of water entering the Jordan had declined because of lower precipitation, but found that in fact, the amount of precipitation in this region has been fairly stable for the past four decades. Despite this, the sea level no longer rises during the winter rainy season, as it generally did three decades ago.

They also found that the drop in the sea level over the summer has remained stable over the decades, even though that is when most of the water used by the potash industry is pumped. Thus even if this industry is using more water, that isn’t the cause of the falling sea level, they said.

The researchers therefore concluded that the accelerating drop in the sea level must be due to the construction of dams along the Jordan River’s tributaries in Syria and Jordan. These dams can store up to 500 million cubic meters of water, and both countries use much of that water. Syria alone has built more than 40 dams that shut off the flow of water in the Rukad and Yarmouk rivers.

These dams account for much of the increased annual shortfall in the Dead Sea’s water intake, which stood at 400 million cubic meters 30 years ago but has risen to 700 million cubic meters over the last decade, the study said.