4.3 Water-resources development and management
The United Nation's partition proposal of 1947, which divided Palestine into Jewish and Arab states, ignored water problems. The 1948 Arab-Israeli war aggravated the difficulties of cooperative water development and management. The failure of negotiations to develop a multilateral approach to waterresources development and management reinforced unilateral action. Though the Unified Plan (see Appendix C) was not ratified, both Jordan and Israel undertook to operate within their allocations. Their two major projects undertaken were the Israeli National Water Carrier and Jordan's East Ghor Main Canal.
The design of the East Ghor Main Canal (EGMC) was begun in 1957; its construction began in 1959, and the first phase up to Wadi Zarqa was commissioned in 1966. The King Talal dam, situated on the Zarqa River, with a storage capacity of 56 million m³, and an 18-km extension of the EGMC were completed in 1977 at a cost of US$52 million (fig. 4.2).
Smaller dams were built on the rift-side wadis from the late 1960s, including the Kafrain dam (3.8 million m³) and the Wadi Ziqlab dam (4.3 million m³). The rift-side dam scheme on the Wadi Shueib was intended to store winter flows for downstream irrigation; however, it could not effectively store the design volume, owing to substantial leakage through a gravel formation and limestone geology in and around the reservoir. The reservoir has never been filled with water up to the design high-water level since the completion of the dam.
The Wadi Arab dam, completed in 1987, has a total storage capacity of 20 million m³ and cost US$50 million.
Present surface water consumption is estimated at 336 million m³ per year, almost all of which is for irrigation, including approximately 102 million m³ for upland irrigation and 229 million m³ for irrigation in the Jordan valley. Of this, approximately 110 million m³ is diverted from the Yarmouk River through the EGMC, and about 119 million m³ comes from the rift-side wadis.
Owing to topographic and hydro-geotechnical problems, the construction of storage dams in Jordan is extremely costly. New investment in storage dams in Jordan can be justified only for the supply of municipal and industrial water or for the irrigation of high-value, highyielding crops using water-conserving technologies.
The water shortage in Jordan is most noticeable in domestic use. The Deir Alla pumping station, which has an installed capacity to pump, treat, and convey 45 million m³ of water per year from the EGMC, was completed in 1988. The scheme involves pumping water up about 1,300 m, and the operating costs are excessively high to sustain the quality for drinking purposes. Due to priority use in the irrigation sector, the system is not allowed to supply precious water during the summer season, and consequently only about 28 million m³ of water are being pumped a year.
The government strategy up to the present has been to use groundwater resources for both M&I and agriculture use, and to use surface water primarily for irrigation. Domestic water supply depends exclusively on the groundwater supply, owing to its better quality and the higher elevation of the water body than that of the surface water resources. Groundwater pumping amounted to 155 million m³ per year in 1985, which exceeded the safe yield in some wellfields, including the Amman-Zarqa aquifer. Almost all the renewable groundwater resources have been excessively developed, lowering the piezometric level and causing deterioration in the quality of water in some aquifer systems. The Disi is the only remaining significant aquifer. It is, however, a fossil aquifer, with an estimated safe yield of about 110 million m³ per year over a 100-year period.
When Jordan's last major potential water sources, Disi groundwater and the Al-Wuheda dam, are fully developed, there will be no alternatives except the use of non-conventional water resources and/or importation of water from other countries.
4.3.1 Surface water resources
Surface water resources are dominated by the Yarmouk and Zarqa Rivers, which provide the majority of the irrigation water for the Jordan valley. Irrigation in the Jordan valley in the past has been made possible only by largescale public investments in water diversion such as the East Ghor Main Canal and water storage dams, including the King Talal and the Wadi Arab, to utilize the potential of surface water resources. The King Talal dam on the Zarqa River was completed in 1979 to collect not only natural flows in the river system but also sewage effluents, both treated and untreated, from the population centres of Amman and Zarqa. Sewage effluents constitute an increasing proportion of the water stored behind the dam, and the amount of treated sewage in northern Jordan is expected to increase from 29 million m³ in 1985 to 116 million m³ in 2005 and 165 million m³ in 2015 (World Bank 1988). Although the water quality of the reservoir is still good and suitable for the cultivation of most crops through drip irrigation except for leafy vegetables, use of King Talal water for M&I, even after treatment, has to be avoided on account of the health risks.
Small dam schemes have been implemented to provide embankment dams with heights of 30-38 m on small streams in the rift-side wadis, including the Ziqlab (4.3 million m³ of storage), the Shueib (2.3 million m³), and the Kafrain (3.8 million m³) since 1968. As mentioned earlier, the dam on the Wadi Shueib was intended to store winter flows for downstream irrigation, but it could not effectively store the design volume owing to substantial leakage through the gravel foundation and limestone geology in and around the reservoir.
The Wadi Arab dam was originally planned to store 30 million m³ of spring flow per year. However, the flowing spring suddenly stopped because of groundwater development in the adjacent wellfield in the wadi in 1985. The dam design had to be amended to store increased winter flow from the EGMC by pumping up 100 m for M&I water supply during the summer season. This was made possible by raising the dam height and changing the supply objectives, including the M&I use. The combined capacity of the King Talal and Wadi Arab dams was increased to 130 million m³ when the dam heights were raised at the end of the 1980s.
WATER-RESOURCES DEVELOPMENT TN THE YARMOUK BASIN The Yarmouk River, which has a mean discharge of 400 million m³ per year, provides almost half of Jordan's surface-water resources. The water in this river, after allowing some 17 million m³ per year for downstream users in neighbouring countries, is diverted through the EGMC, an irrigation canal that runs along the Jordan River to serve agricultural water needs in the Jordan valley. The shortage of groundwater resources to meet growing municipal and industrial water demands in north Jordan has required the conveyance of 45 million m³ of water per year from the EGMC to Amman by pumping an extremely high head of 1,300 m from the Deir Alla treatment and pumping station (200 m below sea level) to the terminal reservoir (1,100 m above sea level). The schematics of water-transport systems in north Jordan are shown in fig. 4.3.
THE AL-WUHEDA (MAQARTN) STORAGE DAM SCHEME. The AlWuheda dam, first conceived as early as 1956, is soon to be constructed in the northern area of Maqarin, about 20 km north of Irbid, to store the waters of the Yarmouk River.
The estimated stream-flow at the Maqarin gauging station is 273 million m³ per year on average, which includes the flood waters that are discharged downstream without any use. On the basis of the riparian agreement between Syria and Jordan in 1988, preliminary work for an 800-m-long diversion tunnel was completed at the end of 1989. The reservoir is to have a gross capacity of 225 million m³, with an effective storage volume of 195 million m³ annually. The water would irrigate an additional 3,500 ha in the Jordan valley and supply 50 million m³ of water a year to the Greater Amman area and the eastern heights. A power station near the dam would generate an average of 18,800 kWh of electricity a year. Syria will use part of the water and 75% of the total hydroelectric power generated. The project was stopped, however, by opposition from Israel, which wanted more water in the Yarmouk River downstream.
4.3.2 Groundwater resources
Groundwater has been exploited extensively in northern Jordan because the population was originally concentrated in this region. Groundwater has been used exclusively for M&I water supply, owing to its better quality and higher elevation than any of the surface water resources.
The Amman and Zarqa wellfields, which were developed to supply water for the municipalities of Amman and Zarqa, had the capacity to provide 16-17 million m³ per year in the 1950s to supply 50% of the demand. Azraq oasis, 100 km east of Amman, was developed to supply M&I water for Amman municipality. To meet the increasing demand for M&I use in the 1980s, both the Amman-Zarqa and Azraq wellfields were over-developed, lowering their piezometric heads, which caused deterioration in their quality.
Two important artesian wellfields, the Mukheiba and the Wadi Arab wells, were exploited in the mid-1980s in north-west Jordan. The Mukheiba wells, near the Adasiya intake site of the EGMC, are currently used for irrigation in the Jordan valley through an 11.5-km canal with a capacity of 3 m³/sec. The sustained yield of the wellfield is estimated to be 20-25 million m³ per year, and its quality is suitable for drinking purposes. The Mukheiba wells represent the best available source for incremental supply of M&I water to the Jordan uplands. The Wadi Arab wellfield, located just upstream of the Wadi Arab dam and reservoir, has been developed to tap the aquifers in the Amman formation (B2) with an estimated safe yield of 10 million m³ per year. The highly confined groundwater in the Amman formation is believed to supply a group of springs in the wadi beds which were the source of base flow of the Wadi Arab; abstraction of the artesian water from the formation has substantially reduced the base flow of the Wadi Arab and the Wadi Arab reservoir. The Wadi Arab dam is now largely dependent on pumping from the EGMC for recharge and storage.
Two other wellfields, the Wadi Ajib (15 million m³ of safe yield per year) and the Wadi Dhuleil (20 million m³ of safe yield per year), situated to the north and north-east of Amman, have been exploited for the purpose of local upland irrigation and M&I use (World Bank 1988). The Wadi Ajib wellfield is being over-developed to abstract 14 million m³ per year for M&I water supply and 14 million m³ for irrigation, while the Wadi Dhuleil wellfield is developed exclusively for irrigation purposes. The quality of the aquifer below the irrigated land has suffered progressive deterioration from over-pumping and contamination by irrigation return flows.
The Disi aquifer (350 km south of Amman) is the most precious and extensive aquifer in Jordan. It is being exploited both for M&I use for Aqaba and for arid-land irrigation. Greatly enlarged areas of land have recently been developed for agriculture or are being planned for, which implies much higher extraction rates. As the aquifer is extremely expensive to develop for irrigation because of its depth, irrigated agriculture is unlikely to be economical. Furthermore, Disi as a typical fossil groundwater, source, which with the AlWuheda dam, represents Jordan's last substantial unexploited fresh water resource, should be regarded as a strategic water reserve.
Owing to the scarcity of rainfall and water resources, the potential for hydropower generation is quite small. Since priority is given to irrigation and M&I purposes, most of the energy produced cannot be dependable. There are only two existing mini-hydro-power plants, which were completed in 1987: two 2 MW units installed at King Talal dam, and a 375 kW unit at Wadi Arab dam. For the Wadi Arab plant, the water is pumped from the EGMC for storage of surplus water (1.2 m³/sec) and released back into the canal during times of deficit (1 m³/ see). The annual potential energy generation of these two plants (12 million kWh) represents only 0.2% of the expected total power generation in Jordan in 1990. The only future hydro-power plant foreseen would be associated with the Al-Wuheda dam and have an installed capacity of 15 MW. The recent riparian treaty between Jordan and Syria envisages that 75% of the electricity produced would be consumed in Syria.
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