Eco-logic

Israel's National Water Carrier: Both Boom and Bane

Fifty years after the ground-breaking project was inaugurated, it appears that its environmental damage may be irreversible.

Daniel Rosenbloom

The National Water Carrier marks its 50th anniversary this month, providing an opportunity to consider this project’s great importance, as well as the significant environmental damages it has caused to Lake Kinneret, the Jordan River and agricultural crops in various areas.

The National Water Carrier, whose construction took 10 years, was built by Mekorot, Israel’s National Water Company and designed by the Tahal Group. It consists of some 134 kilometers of large pipes, tunnels, reservoirs and 34 kilometers of open canals. Its water flows to reservoirs in the Lower Galilee and are purified and filtered in an advanced facility completed about a decade ago.

Thanks to the water carrier, Israel can channel large amounts of water from one region to another. The Water Authority can decide how to divide the water demand between the Kinneret and the groundwater reserves. The groundwater can also be channeled to the water carrier and to pipes installed between the Yarkon springs and the Negev region, which convey the water 150 kilometers further, to Mitzpeh Ramon.

For many years the water carrier channeled an average 380 million cubic meters of water a year from the Kinneret. In some years, like 2004, the amount increased to 525 million cubic meters. The large amount of water channeled from the lake to other areas lowered the Kinneret level by some two meters. The decision to use the carrier to convey drinking water as well as irrigation water turned it into a vital means of supplying water to highly populated regions.

In recent years the large desalination plants built along the coast have been providing a large part of the water for domestic consumption. Consequently, the dependence on the water carrier has decreased in many regions.

This forced Mekorot to set up a water carrying system in the opposite direction – from south to north – dubbed the new water carrier. At the end of this year 75 percent of the water for domestic consumption will be supplied by the desalination plants in Ashkelon, Hadera, Palmahim and Sorek (near Rishon Letzion).

But alongside the water carrier’s achievements, such as its help to developing farming and communities, it has far-reaching environmental impacts. Lake Kinneret, once a natural water source into which water flowed from the Jordan and emerged back into the river on the south side, turned into a reservoir whose southern exit has been dammed. The lake’s level still depends on rainwater, but also on the amount of water pumped out of it. Its ecologic system is constantly undergoing changes and fluctuations due to the sharp changes in its water level.

The southern Jordan River and Dead Sea paid the highest price. The amount of fresh water that flowed in them has diminished to less than a tenth of what it used to be, and the lake’s level is descending at a rate of one meter a year. The water carrier project has drastically dwindled the water flow in the Yarmuch River, once the Jordan’s main tributary in the south. In recent years sewage water and salt springs that had been diverted from the Kinneret were channeled into the Yarmuch, whose water quality deteriorated.

The extended use of Kinneret water also had an impact on the quality of soil and agricultural crops, since the salt concentration in the Kinneret is higher than in groundwater. A case in point is cited in a study conducted by Dr. Avner Silber of the Northern R&D, a division of the Galilee Technology Center (MIGAL). Silber compared between a banana plantation watered with desalinated water and one watered with Kinneret water. The study shows that the plantation watered with Kinneret water suffered damage to the bananas’ root system due to the salt concentration, and a larger amount of water was needed to achieve a crop similar to the one yielded by the plantation irrigated with desalinated water.

The salt damages were even greater when treated sewage water, which contains more salt due to domestic use and other sources, was used to irrigate the banana plantation.

Cutting the use of water from the National Carrier and increasing the use of desalinated water could reduce the salt damage. Some scientists believe, however, that irrigation water should also be desalinated, to prevent the salination of soil and groundwater.

As for the fate of the southern Jordan River and Lake Kinneret, it seems the desalination plants will not bring them back to their golden days. The population of Israel and the neighboring countries will continue to grow in the coming years, and experts fear that despite the added desalinated water, extended use will have to be made of rivers and groundwater.

The Water Authority has recently agreed to convey water from the Kinneret to the southern Jordan River, instead of sewage water from the area’s communities, which will be treated and used for irrigation. This will help to improve the river’s water quality, but won’t make a great difference to the situation.

As for the Dead Sea, unless the ambitious but environmentally problematic project to channel large amounts of water to it from the Gulf of Eilat is implemented, it will continue to shrivel. The bitter truth is that this lake will continue paying the price of the water carrier’s triumph and the success of the other facilities vital to human survival in the region.