Shortage of water is perhaps the most crucial environmental and development problem in Israel. This deficit is exacerbated by the deteriorating quality of water resources due to demographic, industrial and agricultural pressures.
Israel’s water sources are limited by the country’s geography, geology and climate. Seventy-five percent of annual rainfall is concentrated into the four winter months, with at least six hot, rainless months. Most of the annual precipitation falls in the northern part of the country, leaving the south largely unarable. Israel’s semi-arid conditions and the unpredictability of rainfall necessitate a water management policy which is based on the maintenance of a long-term reserve for water regulation and use, the ability to cut allocations for water use in drought years, and the development and use of unconventional water sources.
About two-thirds of Israel’s annual renewable water sources (from rain) are collected in the three major reservoirs the coastal aquifer, the mountain aquifer, and the Sea of Galilee. The rest is collected in other groundwater reservoirs, flows in streams or gushes from springs.
Groundwater flows in two major aquifers: one along the coast and the other further inland. The coastal aquifer’s average annual replenishment rate is about 280 million m3, while the inland, or mountain, aquifer has an annual refill of about 350 million m3.
The Jordan River system is the most important surface water resource in Israel. It is divisible into two major subsystems. The upper Jordan includes the river’s sources and northern tributaries, the Hula Valley, and the Sea of Galilee. The lower Jordan begins at the southern tip of the Sea of Galilee, and ends where the Jordan flows into the Dead Sea. The two subsystems are different in their characteristics and in the changes made in them since the Jordan waters were first used on a national scale.
The upper Jordan is noted for the high quality of its water (with salinity never exceeding 20 mg chloride/liter). The flow of water in the different parts of this system is as plentiful now as in the past. The draining of Lake Hula helped reduce water loss from evaporation in this part of the river by about 60 million m3.
The Sea of Galilee (Lake Kinneret), which divides the upper and lower portions of the Jordan River system, is the only fresh water lake in Israel. It is located about 209 m below sea level. The area of the Sea of Galilee is 170 km2; its maximum depth is 43 m, and its maximal volume is about 4.3 billion m3. The water level, fluctuating in accordance with its use in the national water system and the amount of precipitation and inflow, varies between 213 and 208.9 m below sea level.
In the lower Jordan, annual water flow used to be approximately 1.25 billion m3 (500 million m3 each from the Sea of Galilee and the Yarmouk River, and 250 million m3 from other tributaries). Today, the flow is greatly reduced because the water is impounded in the Sea of Galilee and the Yarmouk. In future, this exploitation is expected to reduce flow in the lower river to 200 million m3 yearly. The quality of water in the lower part of the Jordan is affected by seasonal changes in salinity, especially as a result of the diversion of saline springs away from the Sea of Galilee in order to reduce salination, and by industrial and domestic effluents.
Israel’s widely dispersed water resources have been consolidated into an integrated water supply network serving all but the extreme southern region of the country. The National Water Carrier forms the principal leg of this system: it is composed of canals, tunnels, pipes and reservoirs. All regional supply networks are linked to the National Water Carrier, which conveys water from the north, where it is most plentiful, to the south, where it is scarce. The Sea of Galilee serves as the principal storage reservoir of the system, but groundwater pumped from aquifers is added to the main stream of the Carrier as it flows southward. When water demand is low due to rainfall, water from the Carrier is used to artificially recharge groundwater sources.
Shortage of water is reflected in Israel’s per capita water potential 350 m3 per annum, among the lowest in the world. United States per capita water potential is, for example, 100 times larger, and that of New Zealand nearly 300 times greater than Israel’s potential. Many Middle Eastern countries also enjoy a much greater water potential: Syria and Turkey ten times larger; Lebanon and Egypt three times Israel’s per capita water potential. Of neighboring states, only Jordan is poorer in water resources than Israel (Figure 20).
The total renewable water potential of Israel is less than 2,000 million m3 per year, a quantity sufficient to irrigate about 10% of the gross area. By the year 2000, total water resources are expected to reach 2,150 million m3 52% groundwater and fresh water springs, 31% surface water from the Jordan watershed, 12% marginal water, and 5% floodwater. The increase of 150 million m3 will come from treated wastewater, rainfall-increasing techniques which could boost rainfall by 15%, and desalination (Figure 21).
Water resource development and consumption have grown rapidly since the establishment of the State of Israel. Today, all feasible resources are exploited, including springs, groundwater reservoirs, phreatic and artesian aquifers, and the Jordan river system. This latter resource, which provides close to a third of Israel’s annual water supply, is heavily tapped. However, pumping from the Sea of Galilee cannot be increased without the risk of increased salinity due to saline springs on the lake bottom. Increased pumping could also adversely affect water quality by creating an unbalanced growth of algae. The fresh water streams of the coastal plain have been drained to the point of nonexistence, due to tapping the water at the source and integrating it into the national network.
Moreover, the last two decades have witnessed a net loss in renewable water. Withdrawal of water exceeding the natural recharge rate in Israel’s coastal, sandstone aquifer has led to sea water intrusion; Israel’s inland aquifer, a deeper, karstic limestone system, has also been penetrated, although to a lesser degree, by saline water. In recent years, annual water consumption has nearly equalled over-withdrawal, making restoration a very long-term, difficult goal.
Pollution of Water Sources
Under conditions of water scarcity, on the one hand, and intensive development, on the other hand, the degradation of water quality becomes a critical problem. Curbing the process of water quality deterioration is one of the central challenges confronting the environmental administration in Israel.
– The Coastal Aquifer
About one-third of Israel’s population and a major portion of its industry and agriculture are concentrated in the region overlying the coastal aquifer. Chemical and microbial pollutants, salination, nitrates, heavy metals, fuels and toxic organic compounds all threaten to contaminate the aquifer. Salination of the coastal aquifer has resulted from the intrusion of sea water and from the slow accumulation of dissolved salts from natural sources. Overpumping further exacerbates groundwater deterioration, since lowered groundwater levels prevent the flushing of pollutants and salts into the sea. In the last 20 years, chloride concentrations in the coastal aquifer have increased from 100 mg/liter to 155 mg/liter on average an average increase of 2 mg/liter a year. The import of saline water from the Sea of Galilee for irrigation and groundwater recharge and the use of effluents for irrigation compound the problem. Today, the salinity level of the coastal aquifer endangers such crops as citrus, avocado, vegetables and flowers. The Hydrological Service estimates that by 1992 some 20% of the wells in the coastal aquifer will reach a salinity level exceeding 250 mg/liter, unsuitable for agricultural irrigation.
Nitrate concentrations in the coastal aquifer have increased considerably because of intensive use of fertilizers in agriculture. Nitrate pollution also results from the use of treated effluents for irrigation. Over the last two decades, nitrate concentrations have doubled from 25 mg/liter to 50 mg/liter. The anticipated rise in nitrate concentrations at an average rate of 0.2 – 1.0 mg/liter per year will further exacerbate the problem. The Ministry of the Environment has prepared regulations on effluent irrigation, limiting nitrate concentrations in the irrigation of areas overlying the northern and central parts of the coastal aquifer.
Contamination by heavy metals is minimal and is limited to areas surrounding industrial areas. Due to the slow transit rate of heavy metals through the ground, the problem will become more evident in future years. The Ministry of the Environment has prescribed limitations on heavy metal concentrations in effluent water used for irrigation of areas overlying the coastal aquifer. Regulations proposed by the ministry also prohibit the establishment of waste disposal sites in areas where the risk of groundwater contamination is high.
Contamination of groundwater by fuel was discovered at five sites during 1990. A special team is responsible for various aspects of the problem, including prevention, cleanup and surveys. The Ministry of the Environment is upgrading its involvement in this issue through cooperation with the team, promulgation of relevant regulations, and surveys to assess the scope of the problem.
Data on organic micro-pollutants in water sources have only recently started to accumulate but standards have not yet been set by the Ministry of Health. The Ministry of the Environment has commissioned a number of research studies on the subject. The data have revealed relatively high levels of organic micro-pollutants, many of them suspected carcinogens, in some of the wells of the coastal aquifer. A survey conducted recently by the national water company, Mekorot, revealed that wells contaminated with heavy metals from industrial areas were also contaminated with synthetic organic chemicals. Contamination was also discovered at other wells but at levels below international upper limits. In its draft regulations on effluent irrigation, the Environment Ministry prohibits irrigation with water containing tri-halo-methanes in levels and in areas which threaten to contaminate drinking water.
In contrast to the dearth of data and tests available on chemicals in drinking water, tens of thousands of tests on the microbiological quality of drinking water are conducted each year. These surveys show that some bacterial pollution exists, especially in the north. To solve the problem, several measures must be adopted, including separation of wells from pollution sources, chlorination or other disinfection means in the short and medium terms, installation of treatment systems, and on-line monitoring in sensitive areas. Israel’s regulations on drinking water quality set a limit on the types and concentrations of microbes in drinking water, and specify requirements for sampling and testing.
– The Mountain Aquifer
Because of the deterioration in both quantity and quality of the water in the coastal aquifer, the mountain aquifer now constitutes the main supplier of drinking water in the country. This deep limestone aquifer is especially prone to contamination due to its karstic nature and because of the quick transit of pollutants through it. The potentially rapid rate of saline water infiltration to the aquifer from surrounding saline water sources – – some with a salinity level higher than seawater constitutes a real danger.
– The Sea of Galilee
During the last 50 years, several changes made in the catchment basin of the Sea of Galilee have modified the balance of the lake’s ecosystem. Draining of the Hula Lake in the 1950s caused sediments and nutrients to flow directly into the lake. Increased population, industry and agriculture in the lake’s watershed area led to contamination of the Sea of Galilee by several different pollutants.
In light of the above, the need to oversee the environment of the Sea of Galilee and its watershed and to protect it from nutrient overload, agriculture, grazing, sewage, and even tourists, led to the organization of an effective management system including coordination of research with practical administration and long- range comprehensive planning. A number of steps have been taken in recent years to prevent the introduction of sewage and fish pond water into waterways leading into the Sea of Galilee, resulting in marked decreases in salination levels, bacterial and dissolved nitrogen concentrations, and number of incidents of pesticides reaching the reservoir. On the other hand, a gradual rise in total nitrogen concentrations, a clear decrease in zooplankton growth, and an increase in algal biomass have been noted. Proper management, accompanied by additional pollution-prevention activities, is expected to halt these negative trends and even improve the quality of the water. Water from the Sea of Galilee will meet new, stricter drinking water standards of no more than one turbidity unit only when filtered. The new standards are scheduled to come into effect in 1996.
Management of the Sea of Galilee is largely in the hands of the Kinneret Authority. The Authority was established in 1971 to implement the recommendations of the Kinneret Limnological Laboratory. Together, the Authority and the Laboratory have proven invaluable to the well-being of the Sea of Galilee. The Kinneret Authority works to preserve water quality by keeping effluents out of the lake, preventing incursion from the peaty soils of the Hula Valley, regulating agricultural activities in the catchment basin, controlling farm runoff, and balancing the fish population to prevent unwanted algae growth. Shore development is also managed by the Kinneret Authority. The case of the Sea of Galilee serves as an excellent example of what effective water quality management can achieve.
– Streams and Rivers
The coastal rivers are the most seriously degraded of Israel’s natural systems. Few contain natural water, and some have dried up completely. Others carry sewage of various grades of treatment, industrial effluents, and agricultural run-off. Large quantities of silt have built up on river bottoms. Although the rivers are flushed out by floods every few years, this rids them of only some of these pollutants.
River rehabilitation and pollution prevention figure heavily in the Ministry of the Environment’s planning. Administrative complexities sometimes make action on this front difficult, as rivers are usually located under the jurisdiction of several different local authorities and various public bodies are responsible for them. The location of heavy pollution sources on or close to river banks adds to the problem.
An example of successful rehabilitation of a badly polluted river is the work now in progress on the Yarkon River. The 27- kilometer long Yarkon River, originally fed by springs which have been diverted through the National Water Carrier into the Negev, flows through Israel’s most populated area. In an effort to improve the state of the river, the Yarkon River Authority was set up in November 1988, with the goal of carrying out immediate cleanup activity, restoring the Yarkon to its former beauty, and developing recreation and holiday spots along the river. In recent years, extensive efforts have been made to remove accumulated trash and debris from the river and to clean the river banks. Administrative and legislative measures are being taken to ensure that sewage is not dumped into the river and monitoring is undertaken to ensure that vegetation and fish are not damaged. Rehabilitation plans are currently being formulated for additional rivers.
Sewage Treatment, Effluent Reuse and Use of Marginal Water
The combination of severe water shortage, contamination of water resources, densely populated urban areas and highly intensive irrigated agriculture, make it essential that Israel put wastewater treatment and reuse high on its list of national priorities. The well-documented climatic and geographic constraints facing Israel led its engineers and agronomists to begin research on water reuse as soon as the State was established.
Wastewater production has more than doubled since the mid- 1960s, reaching about 320 million m3 annually in recent years. This figure will increase to at least 410 million m3 by the turn of the century with growth in both population and industry.
By law, no industrial plant which produces industrial wastewater can be approved until it ensures adequate treatment of its wastewater prior to discharge into the municipal sewage system. Thus, many factories have plants of their own for treatment of industrial effluents. Better control and monitoring are needed to ensure the law is enforced.
A national program for sewage was drawn up in 1970: by 1973, the Israel Sewerage Project went into effect. Over $160 million were invested in the program, which comprised a large scheme for the densely populated Tel Aviv metropolitan area, two regional projects and forty-four smaller-scale municipal projects.
A 1989 survey on the collection, treatment, and utilization of effluents showed that 90% of the wastewater is seweraged, 80% is treated and 70% is reused. The significant increase in treated sewage is attributable primarily to the operation of the Dan Region (Metropolitan Tel Aviv) Wastewater Plant, where the quantity of treated wastewater rose by 328% between 1982 and 1989, from 24.6 million m3 (33.7% of the total quantity of raw sewage) to 80.9 million m3 (100% of the raw sewage). In the rest of the country, the quantity of treated wastewater rose by only 35% during the same period.
The Dan Region Wastewater Project is a sophisticated system serving an area of 220 km2 encompassing the large metropolis of Tel Aviv-Jaffa and seven other municipalities, with a population of 1.78 million. Ninety percent of the wastewater processed comes from households, 10% from industry. The Dan Project provides for biological treatment of wastewater followed by chemical treatment. The secondary effluent is then recharged into the groundwater aquifer by means of spreading basins for additional polishing and long-term storage. The water is eventually pumped and used for unrestricted irrigation in Israel’s arid Negev desert. An extensive hydrological and water quality monitoring program, carried out by means of a network of observation wells and recovery wells surrounding the recharge basins, has confirmed the high quality of the reclaimed water.
The objectives of the Dan Project, to prevent year-round pollution along the Tel Aviv shoreline, and to reclaim the wastewater for agricultural irrigation purposes, are being met.
In the Haifa region, another sophisticated, large-scale project treats about 30 million m3 of wastewater yearly. After chlorination, the effluent is piped eastward 30 km to irrigation reservoirs that serve the Jezreel Valley. Numerous smaller municipal and local wastewater treatment systems exist. The success of the Dan Project and these others should be taken as models for those parts of the country where adequate sewage treatment is still lacking.
Apart from the usual motives for sewage treatment sanitation, public health, environmental quality and protection of water resources the incentive for extensive effluent reuse in Israel has been the need for an additional, unconventional water source for agricultural irrigation. Effluents constitute the most readily available and cheapest source of additional water, and provide a viable solution to Israel’s water scarcity problem. By the year 2000, over 400 million m3 of effluent may be reused for irrigation in agriculture, replacing fresh water allocations for that purpose.
Today, over 70% of all treated wastewater in Israel is reused in agriculture. As 65% of all Israeli water is allocated to agriculture, this represents an enormous savings in terms of fresh water. Increased demand for good quality water for domestic and industrial consumption from 33% today to over 50% of water consumed by the year 2000 will further accelerate the transition to reclaimed water for agricultural use in designated areas (Figure 23). Studies on the human health consequences of permissible wastewater irrigation have shown that no negative effects have resulted from the massive reuse of treated wastewater practiced in Israel over the last thirty years.
The Ministry of Health maintains a permit system designed to ensure that irrigation with effluents is limited to crops such as cotton, corn for fodder, etc. Only highly treated effluents, after chlorination, are used for irrigation of orchards and other edible crops for human consumption.
With the increasing severity of water shortage in Israel, and taking into account the fact that essentially all naturally replenishible water sources are now being fully utilized, wastewater reuse remains a major potential source of water for agricultural use.
The only remaining potential water sources, once wastewater is fully utilized, are implementation of cloud seeding on an even larger scale, and desalination of brackish and sea water. Desalination techniques, especially reverse osmosis, are already being used in some areas to increase Israel’s water potential. Extensive research on desalination is carried out, and desalinated brackish water forms a major part of the water supplied to Eilat, at the southern tip of Israel.
Water conservation is an essential element in overall water resource management. In the agricultural sector, substantial savings have been achieved through technological improvements in irrigation methods, including micro-sprinklers, drip irrigation, computerized, automated control systems, etc. Furthermore, Israeli research on agricultural techniques has led to the introduction of crops requiring a minimal amount of water, or able to thrive on brackish water without diminished yield.
In industry, water is conserved by the recirculation of cooling water and steam, pressure reducers, and reuse of treated industrial wastewater. Notably, despite the accelerated growth in industrial activity in Israel, industrial use of water has not increased substantially.
In the urban sector, municipalities have undertaken improved watering techniques for public lawns and gardens (night-time sprinkling, for example), and replacement and maintenance of pipes to prevent leaks and explosions.
A highly successful public education campaign has been undertaken by the Water Commission, based on the motto "Don’t waste water every drop counts." Citizens are encouraged to use water saving devices in homes and gardens, to repair leaky faucets, and to report leaks in the public sector promptly. Water conservation is now integrated into the school curriculum, ensuring that Israeli youth grow up with an awareness of the problem of water scarcity in their country, and the knowledge and the tools they need in order to conserve this precious resource.
Responsibility in matters pertaining to water quantities, production and supply is entrusted to the Minister of Agriculture, who appoints a Water Commissioner to manage the country’s water resources. The Ministry of the Environment is responsible for water quality in all natural resources. The Ministry of Health is responsible for the quality of drinking water in the pipeline.
The Water Commissioner allocates water to local authorities and other large users. The local authorities are in turn responsible for developing, maintaining and operating the water supply systems within their boundaries. This includes metering residential, public, commercial and industrial use, levying progressive water charges, and publishing information designed to encourage efficient water use.
Several other public bodies also play a role in water administration. These include the Water Board, the Water Planning Committee, the Water Tribunal, and other bodies which help ensure public participation in water affairs, and provide a forum for appeal against any unreasonable, unjustified or miscalculated decisions taken by the Water Commission or local authorities.
Supervision and authority over wastewater treatment is divided among four government ministries: Interior, Environment, Health, and Agriculture. Local authorities are responsible for collection, treatment and disposal of wastewater. While local authorities are required by law to install sewage systems, wastewater is treated to varying degrees by different municipalities. In the past, opposing considerations frequently guided the numerous bodies responsible for sewage, especially with regard to location of treatment plants, level of treatment, and utilization of the effluent for agriculture. Recently, a decision has been taken to appoint a national administration on sewage, composed of representatives of government ministries and supported by a professional advisory committee, whose role will be to review sewage plans from a professional point of view. This committee will assess large-scale or problematic sewage plans, including inter-regional plans, prepare sewage plans in areas in which the local authorities have failed to do so, and prepare a national masterplan for sewage treatment and effluent reuse.
Legal Framework for Water Protection
Soon after the establishment of the State, Israel’s government declared state ownership of all water resources. The first water laws were enacted in 1955. Today, the Water Law of 1959 is the principal law regulating fresh water in Israel. The law regulates, among other things, the flow of pollutants into the State’s water arteries.
In 1971 the law was amended to include prohibitions against direct or indirect water pollution, regardless of the state of the water beforehand. The amendment provides that no person may throw or cause to flow into or near a water resource, any liquid, solid or gaseous substance, or deposit any such substances in or near the water resource. The Ministry of the Environment is responsible for a significant portion of these provisions.
Israel’s regulations on drinking water set a limit on the types and concentrations of microbes in drinking water, and specify requirements for sampling and testing. Recent amendments to these regulations, promulgated within the framework of the Public Health Ordinance, define water as unfit for drinking if routine microbiological tests reveal more than three coliform microbes or one faecal coliform in a water sample of 100 mm. Regulations promulgated under the same Ordinance specify the treatment required for wastewater, and list the crops on which effluent can be used after receiving various levels of treatment.
In 1991, an amendment to the Water Law was approved. The amendment is designed to facilitate more effective enforcement by such means as significantly harsher fines ($62,500 as opposed to less than $2,000 previously), and obligatory cleanup by polluters. Regulations promulgated pursuant to the law include provisions for the prevention of water pollution from the rinsing of chemical and or biological substances, prohibitions against aerial spraying for agricultural purposes near water sources, and regulations regarding prevention of water pollution from cesspools and septic tanks. More recently, the Ministry of the Environment has prepared regulations prohibiting the placement of sewage lines close to wells, and regulating irrigation with effluents in hydrologically sensitive areas.
The Model Local Authorities By-Law (Discharge of Industrial Sewage into the Sewerage System), 1981, charges all generators of wastewater with responsibility for adequate treatment and disposal in a manner which will avoid health and environmental nuisances and the contamination of water sources. The model by-law has been adopted by many municipalities. In addition, regulations under the Prevention of Sea Pollution (Land-Based Sources Law, 1988) forbid the discharge of wastewater into the sea.
The Local Authorities Sewage Law of 1962 prescribes the rights and duties of local authorities in the design, construction and maintenance of sewage systems. This law requires each local authority to maintain its sewage system in proper condition.
The Streams and Springs Authorities Law, 1965, empowers the Minister of the Environment to establish an authority for a particular stream or part of a stream, a spring or any other water source. The functions of such authorities include the abatement of nuisances and prevention of pollution of the stream or water source for which they are responsible.