The historically low water levels in the Sea of Galilee have been caused by overuse, not climate change-induced drought, researchers from Ben-Gurion University said in a study published this week.
Researchers from BGU’s Geomorphology and Fluvial Research Group said in the September issue of an industry journal that agriculture and flow diversion were the primary reasons for the steady diminishment of Israel’s major source of fresh water.
“Climatic factors alone are inadequate to explain the record shrinkage of the Sea of Galilee,” Prof. Jonathan Laronne and Dr. Michael Wine wrote in their paper published by the Science of the Total Environment.
“We found no decreasing trends in inflow from the headwaters of the Upper Jordan River located primarily in Lebanon and northern Israel,” they said.
Rather, Laronne and Wine said the declining water levels in the upper Jordan River corresponded to a period of expanded irrigation agriculture in which the the rate of groundwater being pumped was doubled.
The researchers said that while an overall increase in temperature would cause water to evaporate, leading to a decrease in water levels, the temperature changes recorded in the Sea of Galilee were not significant enough to explain the observed decrease in water levels.
The researchers said their results demonstrated that to rehabilitate the Sea of Galilee, Israel must stop pumping fresh water from the lake and nearby streams.
According to the Israel Water Authority, the ongoing five-year drought has plunged water tables to the lowest level in at least 98 years, since scientists first began taking taking measurements in 1920.
Northern Israel’s worst drought in a century left the country’s water tables with a deficit of 2.5 billion cubic liters of water, compared to non-drought years.
That deficit is the equivalent of one million Olympic-size swimming pools, water that would normally flow through Israel’s streams and underground water tables toward the Sea of Galilee and other water sources.
In June, Prime Minister Benjamin Netanyahu announced an emergency drought recovery program in an effort to rehabilitate seven streams in northern Israel that would see desalinated water flow directly to the Sea of Galilee.
The NIS 105 million ($30 million) plan aims to pump up to 100 million cubic meters of desalinated water into the lake within four years.
The Sea of Galilee is currently at 214.2 meters (703 feet) below sea level, more than half a meter below the danger zone of the lower red line, and just below the even lower black line.
The black line is a dangerously low level that can create irreversible ecological problems, including an increase in the water’s salinity and algae blooms that can do permanent damage to the water quality, and flora and fauna. Last year, the Water Authority had to pump 17,000 tons of salt out of the Sea of Galilee to ensure that the lower water levels did not cause the water to get too salty.