Israel Water Context

4.  The Water Sources

The Israeli water economy, which today consumes ~2000 million m³/yr, relies mainly (85%) on natural water sources – surface waters (~560 million m³/yr) and groundwater (~1200 million m³/yr). However, with the increase in demand for water, and in view of the full exploitation of the natural sources of water, a need to find other sources was created. Thus, purified sewage waters that are utilized for the agricultural sector (15%) and a scant amount of desalinized waters from various sources are exploited. Beginning in 2005, a large amount of desalinized water from the Mediterranean Sea is also being supplied, which according to the forecast will constitute around 22% of the water consumption foreseen in 2020.

Distribution of the water sources of the Israeli water economy
  according to type (before the beginning of desalinization).

Surface Water

Surface waters are mainly exploited in northern Israel, in the catchment basin of Lake Kinneret. The surface waters flow from the Galilee and Golan mountains to the northern part of the Jordan River (~460 million m³/yr) and to Lake Kinneret, lying at an altitude of -200 m. It should be noted that the amounts of surface water depends directly on the amounts of precipitation each year, and therefore there are large perennial changes. From the Kinneret the waters are pumped to the national water carrier, which transports the water westward and southward, regulating the supply on its way by means of large reservoirs. The quality of the water of the Kinneret basin is good to medium, but requires mechanical, biological and chemical treatment to bring it up to drinking-water standard.

In a large number of the streams flowing to the Mediterranean Sea and to the Dead Sea the floodwaters (the winter swellings) are collected and exploited. In the Taninim stream, for example, around 2/3 of the surface runoff water (~12 million m³/yr out of ~18 million m³/yr ) is caught, and  penetrated through boreholes into the coastal aquifer in order to enrich it. The quality of the waters in the reservoirs is medium to poor, and their use is accordingly limited to agriculture and to enriching the aquifers.

Groundwater

The main groundwater reservoirs (aquifers) of Israel are the coastal aquifer and the mountain aquifer. The mountain aquifer is divided into a number of basins: Shekhem (Nablus)-Gilboa; Yarqon-Taninim; and the eastern mountain basins. In addition to these there are several  smaller basins (from north to south): eastern Galilee and Golan (Kinneret); western Galilee; Karmel (Carmel); and Negev-Arava. The flow direction in each of these basins is dictated by the geologic structure and end drainage: the Jordan Valley in the east or the Mediterranean Sea in the west.

Map of the main groundwater basins.

Exploitation of the groundwater from the aquifers is based on the perennial forecast, and thus it is relatively stable. The waters are exploited through many boreholes, most of them by the national water company "Mekorot," and the rest of them, by private wells. The quality of the groundwater is for the most part high to very high, and is of drinking quality after chlorination and fluorination (addition of chlorine to purify the water and the addition of fluorine for dental health), as required by law. In the 1990s there was a decline in both the quality and in the level of the water in some of the aquifers, and today the Water Commission is carrying out a plan to rehabilitate them.

Average annual recharge to each of the different basins.

Reuse of treated water

The state of Israel is numbered among the countries in which purified sewage water is intensive. Today, around 40% of the domestic-urban sector consumption is restored (recycled), whereas the maximum exploitation potential is around 60-65% of the consumption. Most of the treated water is supplied to agriculture, and a little of it, that of a good quality and up to the standard, is discharged to nature. Treatment of the sewage is carried out in more than 120 purification plants that are scattered throughout the country, the newer ones using the reactive sludge method. The largest plant is located close to Rishon LeZiyyon and recycles the sewage for the Dan metropolitan area, in which around 1.5 million inhabitants live, and industrial sewage in the range of ~10 million m³/yr. Additional large plants recycle the sewage of Haifa (~40 million m³/yr) and Jerusalem (~20 million m³/yr). The restored purified sewage water must meet the standards of the Ministry of Health and today its quality is considered only good for irrigation. This water is transported through separate pipelines to the agricultural areas.

Desalinization

Up to the year 2005 water was desalinized only for local use and in minimal quantities, except by the desalinization installation in the city of Elat. Beginning in 2005, desalinization of water from the Mediterranean Sea was also started on a large scale, in one of four installations planned at this stage. The volume of annual production from the four installations is expected to reach ~300 million m³/yr, that is, an addition of around 14% to the water economy of Israel.