The water level of the Sea of Galilee, on which Jesus supposedly walked, is a national obsession in Israel. Newspapers report its rise and fall next to the weather forecast. Lately the sea, which is actually a freshwater lake, has been falling. It is now a quarter empty. Small islands have emerged above its shrinking surface. 

For the past five years Israel has experienced its worst drought in nearly a century. That has reduced the flow of the Jordan river and other streams that feed into the Sea of Galilee. Less turnover in the lake’s water is leading to increased salinity and the spread of cyanobacteria (sometimes called “blue-green algae”, despite not being algae). As the pressure from fresh water eases, it allows in more salt water from subterranean streams. Climate change is expected to exacerbate these problems, perhaps one day making the lake water undrinkable.

Israel can probably cope. For most of its history the Sea of Galilee was its largest source of drinking water. But over the past decade the country has invested heavily in desalination plants and projects that allow it to reclaim effluents and brackish water. Since 2016 well over half of the water consumed by households, farms and industry has been “man-made”. Less than 70m cubic metres of water will be pumped out of the Sea of Galilee this year for consumption, down from 400m in the past. Some 50m will go to Jordan, which is also suffering from a severe drought.

In Jun 2018e the Israeli government authorised a billion-shekel ($270m) plan to pump desalinated sea water, mostly from the Mediterranean, into the Sea of Galilee. Work on a new pipeline began last month. A freshwater lake has never been replenished in this way, but the scientists monitoring the plan believe it will work similarly to rainfall and will not harm the lake’s unique ecosystem.  By 2020 the new pipeline is expected to pump enough desalinated water into the Sea of Galilee to stabilise its level. 

Excerpts from The Sea of Galilee: Walking on Desalinated Water, Economist,  Dec. 1, 2018