Located in the rim of a desert belt, Israel has always suffered from water scarcity. Archaeological discoveries reveal that thousands of years behind the inhabitants of the region were already worrying for the water conservation, as they it demonstrate a variety of so much systems destined to join and to store the rainwater as to transport it back and forth.
The annual whole of renewable water resources amounts to nearly 1.700 million cubic meters, of which about 65 % is used for the irrigation and the rest for urban and industrial intentions. The water sources of the country include the river Jordan, the Lake Kinéret, and a few small rivers. There are used also natural sources and reservations of groundwaters, which development is controlled to prevent his depletion and the increase of his salinity. All the fresh water sources having been exploited to the maximum, are developing methods to make use of marginal water resources, by means of the recycling of the served waters, the sowing of clouds and the desalination of the sea water.
The National Aqueduct
To overcome regional disparities in the water availability, most of the sources of fresh water of the country has joined in an integrated network. His principal artery, the National Aqueduct, finished in 1964, transports the water from the north and the center, by means of a network of gigantic pipes, aqueducts, open channels, reservoirs, tunnels, dams and stations of pumping, on the semi-arid south.
The chronic problem of the water in Israel
The water scarcity is a fact of the daily life in Israel, where the industry, the agriculture and the modern urban life compete between themselves for the limited water resources of his environment, largely semiarid. The rainfall is not distributed uniformly in the country and the raining season is short. The annual quantities change between almost 1.000 mm. in the north end of the country and 31 mm. in his most southern point. The raining season lasts four months, from November until February, with a rainfall that changes of year in year.
The water consumption, which uses up to the limit the basic supply, has had to Israel to construct an elaborated system of storage and water distribution and to look for additional water sources. This search, which has been closely related to the development of the country from the decade of thirty, has driven to find ways of transporting the water to the arid areas, as well as to not conventional solutions and new methods to increase the existing resources. The problems are tackled by innovative spirit, developing agricultural water saving methods, "he sows of clouds" and use of purified wastes water.
I give of water
The entire quantity of water that is practical and economically suitable for the use - call "the water balance" - is estimated in approximately 1.700 million cubic meters a year. This quantity also represents the due drinking water maximum autorrenovable. Another 200 million cubic meters of brackish water it can be used after happening for desalination processes.
Although the entire rainfall of Israel is several times major than the "balance of water", only one third of this one is usable. Approximately 0 per cent evaporate and 5 per cent flow towards the sea and it is too difficult or costly to recover it. 35 remaining per cent filter towards the subsoil, accumulating in natural aquiferous deposits.
Israel is provided with two principal tanks of fresh water - one under the central saw that crosses the north country on south, and other along the coastal flatness - and several smaller aquiferous deposits. The saw of Judea and Samaria is the area of natural replenishment of several of the biggest and most important underground deposits. The rainwater that accumulates in the exposed rocky surfaces of the hills filters across several substrata, flowing in all directions as groundwaters. The region of Judea and Samaria contributes to the underground currents in the substrata from the Vale of Beit Sheán in the north to Beer Sheva in the south. Approximately half of the resources of drinking water of the country (650 m3 per year) comes from this area.
Nowadays Israel uses more than 95 per cent of his balance of fresh water and foresees that he will need major quantities in the future (to see Table). The consumption in the whole country during 1994 was almost 2.000 millions of m3. The difference between this consumption and the water balance of 1.700 millions of m3 was covered pumping in excess groundwaters and using wastes water purified for the irrigation. The excessive pumping produces a deficit that will have to be re-supplied possibly, and a series of dry years in the decade of eighty increased the deficit to a magnitude equivalent to a finished year of consumption. Later efforts of conservation and the active replenishment of the aquiferous deposits have supported to streak the problem.
An extensive water distribution system allows to the country to overcome the limitations in the supply of several areas. The system began with regional aqueducts and expanded to interregional systems. Since then there has developed a national network centred on the National Aqueduct. Constructed in a period of 10 years, the aqueduct trasporta water of the regions of the north and the center of the country on the semiarid south, using gigantic pipes, aqueducts, dams, tunnels, reservoirs and pumping stations. Most of the aqueducts previously independent have got connected to him, forming a network integrated from Metula in the north to Eilat in the south, and from the river Jordan up to the Mediterranean Sea.
Considered like one of the most developed and versatile of the world, the system distributes in one hour the same quantity of water provided in every 1937, and in one day the entire quantity distributed in 1948. His 6.500 kilometers of tubes come to all the corners of the country and fulfill all the needs.
Not conventional solutions and new possibilities
After using almost all his water resources and in spite of promoting energetic conservation programs, the basic quantity of water of the country keeps on being scarcely sufficient. Therefore, Israel for time considers to be a national mission the suitable use of the existing resources and to look for new sources for the future. These efforts have centred on the following aspects:
Use of the exceeded waters of the winter rains: these waters gathered in artificial lakes (of which 120 were contruidos in the last decade), are used for the irrigation and, when it is possible, to re-supply the aquiferous deposits. The lakes also retain the purified wastes water and waters in transit of one region to other one. The refueling of the aquiferous deposits also helps the evaporation to prevent and, in the coastal areas, the intrusion of sea water. Once under ground, the water is available for his pumping when it is necessary.
Recycling of purified residential and industrial wastes water: of approximately 300 million of m3 per year, this is the biggest source of water that still has not developed entirely. More than one third of this quantity is used nowadays in the agriculture, especially for the cotton cultivation and fruits, products that do not lie straight in the ground. The rest is used to re-supply groundwaters or simply it allows to move up to the rivers and the seas due to the absence of facilities of deposit.
Desalination: Israel is provided with approximately 30 desalination plants, most of them in the field of Eilat. The biggest use the process of inverse osmosis to treat 27.000 m3 brackish water newspapers, fulfilling this way half of the demand of Eilat. Quite the available brackish water in the Eilat-Aravá region is desalted nowadays. The future of the desalination centers on the sea water like source and depends on that find ways of doing that the process is efficient as regards the cost.
Increase of the rainfall: the clouds sowing with glazing of silver yoduro, carried out on the basin of the Kineret from 1976, has increased the annual rainfall in the area in 0 to 18 per cent. The World Meteorological Organization mentioned the Israeli program as the only one in the world that demonstrates as per statistics a significant success.
Conservation: being the most reliable and less costly method to increase the water resources of the country, the challenge that it represents is being faced in all the sectors.
In the agriculture, the advances in the technology of the irrigation, like the irriagación for dripping and the microsprinkling cans, they have reduced the water loss in up to 20 per cent. The irrigation using administration methods computarizados increases these achievements.
In the industry, special recycling facilities are interfering gradually and there are being re-designed by conservation ends the facilities of cooling and other devices of big water consumption. These measurements have done of the industry a leader in the water conservation, with an increase of studied industrial consumption of 100 millions of m3 in 1989/1990 to 130 million cubic meters in the year 2.000.
In the municipal government, the conservation efforts center on the progress of the administrative effectiveness, the repairs and the control of the municipal systems of water. The parks were put under a diet of conservation that includes the selection of plants that need less water, the night irrigation and often minim and the system use of irrigation tending to the conservation. The conservation measurements are applied in all the public institutions under municipal jurisdiction, including to the schools.
In the hearths, central and municipal institutions urge the citizens to save water. The slogan "to waste not even a drop" is known in every hearth in Israel, underlining the dependency on Israel of one of his most limited resources.
Mekorot Ltda. is the national company of water of Israel, person in charge for the administration of the water resources of the country, the development of new sources and he assures the regular water supply to all the places and for all the intentions. Founded in 1937 and with head office in Tel Aviv, Mekorot has dug 1.300 wells, has installed 700 pumping stations (more than 3.000 bombs in operation), he has constructed 00 reservoirs and has stretched 6.500 kilometers of tubes. Also, it controls the water quality in his biological laboratories, constructs and produces plants of desalination and fluoridation, and realizes operations of sowing of clouds.
Source: MFA - Foreign Office of Israel