|Hydropolitics along the Jordan River. Scarce Water and Its Impact on the Arab-Israeli Conflict (UNU, 1995, 272 pages)|
|2. Hydrography and history|
Natural system: Surface water
The Jordan River watershed drains an area of 18,300 km2 in five political entities Lebanon, Syria, Israel, Jordan, and the West Bank (Naff and Matson 1984, 21) (see appendix I, maps 1-4).
Three springs make up the northern headwaters of the Jordan: the Hasbani, rising in Lebanon with an average annual flow across the border of 125 MCM/yr, the Banias in the Golan Heights, averaging 125 MCM/yr, and the Dan, the largest spring at 250 MCM/yr and originating in Israel. The streams from these springs converge 6 km into Israel and flow south to the Sea of Galilee at 210 m below sea level (Inbar and Maos 1984; Kolars 1992) (see table 2.1).
The Yarmuk River has sources both in Syria and Jordan and forms the border between those countries before it adds about 400 MCM/yr to the Jordan, 10 km south of the Sea of Galilee. Beyond this confluence, the Jordan picks up volume from springs and intermittent tributaries along its 320 km meander southward along the valley floor of the Syrio-African Rift. At its terminus at the Dead Sea 400 m below sea level, the Jordan River has a natural annual flow of 1,470 MCM/yr.
Table 2.1 Water balance of the Jordan River system
|Estimated How (MCM/yr)a|
|North Jordan System|
|Hasbani River (Lebanon)||
|Dan Spring (Israel)||
|Banias River (Golan Heights)||
|Local run-off (Upper Valley)||
|Irrigation-return flow (Huleh Valley)||
|Subtotal to Lake Tiberius||
|Spring flow (salty)||
|To National Water Carrier||
|Subtotal to Lower Stem of Jordan|
|River (N. Jordan)||+ 70||570|
|The Yarmuk River||(Al-Fataftah) |
|Flow from Syria||+ 400b||495b||400|
|Syrian irrigation||- 90||- 250'|
|Syrian return flow||+ 20||+ 50 (est.)|
|To East Ghor Canal||- 158b||- 150b|
|To Israel (via Tiberius)||- 100b||- 80b|
|Subtotal to Lower Stem of the Jordan River (Yarmuk)||+ 72||+ 65||970|
|Lower stem of Jordan River|
|Lower Jordan spring flow||+ 185||185|
|Zarqa River and Wadis||+ 322||+ 539||322|
|East Ghor return flow||+ 32|
|Total||+ 611b||+ 604d||1,477|
Source: Kolars (1992).
a. Million cubic metres in an average year; climatic variations can change the values by ± 30%.
b. Conflicting sources of data account for these variations.
c. Smaller values from the Johnston Plan; 1991 evidence indicates as many as 20 small diversionary dams have been built on the headwaters of the Yarmuk in Syria. Larger withdrawal values reflect such possible diversions.
d. Once in the main stream, this water is unusable owing to high salt concentrations.
The salinity of the water rises greatly even as its flow increases, because much of the Jordan's flow is below sea level and the small springs that contribute to its flow pass first through the salty remains of ancient seas. Though the headwaters at the Hasbani, Banias, and Dan have a salinity of 1520 parts per million (ppm), levels at the south end of the Sea of Galilee are 340 ppm. This is diluted to some extent by the Yarmuk, which has a salinity of 100 ppm, but increases significantly downstream, reaching several thousand parts per million by the Allenby Bridge near Jericho. The Dead Sea, a terminal lake, has a salinity of 250,000 ppm, seven times that of the ocean (Naff and Matson 1984).
The river flows through the transition zone from the Mediterranean subtropical climate of Lebanon and the Galilee region in the north to the arid conditions of the Negev Desert and the Rift Valley to the south. Similarly, rainfall patterns vary spatially, with decreasing rainfall generally from north to south and from west to east.
Natural system: Groundwater
The hills along both banks of the Jordan serve as recharge areas for extensive aquifer systems in the West Bank, Israel, and Jordan. Rain that falls on these mountain ridges and does not evaporate or run off as surface water, percolates down to the water-table and then flows laterally, albeit extremely slowly, through the pores and cracks of the underlying rock layers. One measure of an aquifer's utility is its "safe yield," or the amount of water that can be pumped without adverse effects to the water left in storage. This is usually considered to be equal to the annual recharge rate.
There are three principal aquifer systems west of the Jordan (Kahan 1987; Nativ and Issar 1988; State of Israel, Office of the Comptroller 1990) (see appendix I, map 5). Based on the current working assumptions of water managers in Israel, the aquifers have the following safe yields: the north-east basin, which recharges in the northern West Bank and discharges in Israel's Bet She'an and Jezreel valleys, has a safe yield of 140 MCM/yr; the western, or Yarkon-Tanninim, basin, which also recharges in the hills of the West Bank but discharges westwards towards the Mediterranean coast in Israel, has a safe yield of 320 MCM/yr; the eastern basin, which is made up of five separate catchment areas in the West Bank, all of which flow east toward the Jordan Valley, has a combined safe yield of 125 MCM/yr.
The coastal aquifer, another major groundwater source in Israel but without hydrologic connection to those listed above, provides a safe yield of about 280 MCM/yr. The Gaza aquifer, with connection to the coastal aquifer, provides an additional yield of 60 MCM/yr.
Groundwater replenishment within Jordan totals about 270 MCM/ yr in 12 different aquifers, mostly in the Zarqa, Yarmuk, and Jordan catchments (Ghezawi 1991; M. Bilbeisi in Garber and Salameh 1992).
It should be kept in mind that these streamflow and groundwater recharge values are for average annual values in the natural system. The actual amounts are highly variable and depend both on seasonal fluctuations (75 per cent of precipitation falls during the four winter months) and on annual variations in rainfall, which can be as high as 25-40 per cent (Stanhill and Rapaport 1988). Furthermore, the natural system has been dramatically altered by large-scale diversion projects, as is discussed later.
Current water use (see tables 2.2 and 2.3)
Israel has a renewable annual water supply of approximately 1,600 MCM/yr. Of this, 60 per cent is groundwater and 40 per cent is surface water, almost entirely from the Jordan River system. Its water budget is augmented by about 200 MCM/yr from waste-water reclamation and non-renewable groundwater. The 1,800 MCM/yr total is allocated to agriculture (73 per cent), personal consumption (22 per cent), and industrial use (5 per cent). Israel irrigates 66 per cent of its cropland, and has a population of 4.2 million and an annual population growth rate of 1.6 per cent (excluding immigration) (Poster 1989a; State of Israel, Comptroller 1990).
The 800,000 Palestinians on the West Bank consume about 115 MCM/yr, 90 per cent of which is groundwater. Of this total, about 90 MCM (78 per cent) is for irrigation and the rest is for personal use.
Table 2.2 Population projections for countries the Jordan River watershed: Populations and growth rates (without immigration)a
|Entity||1991 Population||Annual growth rate (%)||Extrapolated 2020 population|
Sources: World Resources Institute (1991); Bank of Israel (1991) (Soviet
immigrants); Heller (1983) (West Bank Immigrants).
a. Immigration: Israel anticipates 1 million additional Soviet Jews over the next 10 years; Jordan is absorbing 300,000 refugees from the Gulf War; the West Bank might absorb 600,000 Palestinian refugees in the context of "right of return."
Table 2.3 Current water use and availability
|Percentage to Agr/Dom/Inda|
Sources: World Resources Institute (1991); Israel: Naff and Matson (1984),
State of Israel (1988); Jordan: Garber and Salameh (1992); West Bank and Gaza:
a. Water in the region is allocated between agriculture (Agr), domestic use (Dom), and industry (Ind), with by far the largest share going to the former.
b. Israeli natural potential of about 1600 MCM/yr is augmented through waste-water reuse, some desalination, and, until 1991, a 200 MCM annual groundwater overdraft.
c. Jordan's budget includes 170 MCM/yr of planned use of fossil (non-renewable) aquifers.
d. Gaza budget includes approximately 35 MCM/yr aquifer overdraft which is leading to serious problems of salt-water intrusion.
The 70,000 Israeli settlers use an additional 35 MCM, 95 per cent of which is for agriculture (Kahan 1987,113). The residents of the West Bank, Arab and Jewish, irrigate 6 per cent of the cultivatable land and have a population growth rate of approximately 3 per cent (Poster 1989a, 14).
Gaza, with a population of about 600,000 growing at 3.4 per cent annually, is probably in the most desperate situation hydrographically. Although the Gazans are completely dependent on the 60 MCM/yr of annual groundwater recharge, they currently use approximately 95 MCM/yr. The difference between annual supply and use is made up by overpumping in the shallow coastal aquifer, resulting in dangerous salt-water intrusion of existing wells and ever-decreasing per capita water availability (already the lowest in the region).
Jordan has a total renewable annual water supply of 700 MCM, of which 50 per cent is surface water (mostly from the Yarmuk River). These sources above are augmented by about 170 MCM nonrenewable groundwater per year. Of the total water budget of 870 MCM/yr, 85 per cent is allocated for agriculture, 10 per cent for personal consumption, and 5 per cent for industrial use. Jordan irrigates 10 per cent of its cropland and has a population of 3.3 million, which is growing at a rate of 3.5 per cent per year (Poster 1989a; Garber and Salameh 1992).
Lebanon and Syria are relatively minor consumers of water from the Jordan River, with the former using about 35 MCM/yr from the Hasbani and the latter about 250 MCM/yr from the Yarmuk, each for local irrigation projects near the respective headwaters. Their major sources are the Litani and Euphrates rivers, respectively. The Litani, with an average flow of 700 MCM/yr, lies wholly within Lebanon but, because it flows to within seven kilometres of the Hasbani, it has been included in several planned diversion schemes in conjunction with the Jordan system. Lebanon irrigates 29 per cent of its cropland, and has a population of 2.6 million, and an annual rate of population growth of 2.1 per cent. Syria irrigates 11 per cent of its cropland, and has a population of 10 million, which is growing at a rate of 3.8 per cent per year (Poster 1989a).