va®aea wi air- tf< ti +f' 1> t } r Profile: Tigris/Euphrates River Basins it III 4 M .1 I J CEWRC-IWR-P 29 May 91 Tigris-Euphrates Basin Summary *Projects in Turkey, Syria, and Iraq are expected to greatly reduce both Euphrates and Tigris stream flows and reduce water quality *Already Syria claims Tabqa Damhydropowerplants are operating at only 10%capacitybecause ofAtaturk filling *Estimates of depletion vary; one estimate is for approx. 50 % depletion of Euphrates flowsby Turkey and almost a 30 % depletionby Syria(given completionofTurkey's Gap project and projected Syrian withdrawals); the most likely date for completion of all projects (if at all) is 2040; in the 1960s, Iraq withdrew an average of about 50 % of Euphrates flows *One estimate of projected Euphrates depletions for the year 2000 is 20 % each by Turkey and Syria *Syria and Iraq may be especially affected by reduced flow during low flow years *Of more immediate concern than possible long-term reduction in flow quantity is increased pollution of inflows to Lake Assad on the Euphrates (main water supply source for Aleppo) and to the Khabur River (both in Syria) owing to irrigation return flows; both areas plan for greater use of those waters *Quality of Euphrates flows into Iraq will also beaffected *Iraq has constructed Tigris-Euphrates Outfall Drain to drain irrigation water into Shatt al-Basra and Gulf *Most water withdrawals within the basin are forirrigation;Turkey,Syria,and Iraq all are attempting to expand irrigation programs *Recent projected demands for water withdrawals for Iraq were not available for this study. If some of the projected demands (made in late 1970s) for agricultural use are still valid, there will be massive shortfalls along both the Tigris and Euphrates Rivers upon completion of the Turkish GAP projects. *The Tigris River is less susceptible to Turkish demands because of the substantial tributary inflows. EuphratesTigris *However, duringyears ofmodest of lesser flows, water needs for much of Iraq's irrigation will not be met, given implementation of all Tigris GAP projects. % basin Turkey: 29% 12 Syria: 17 0.2 Description Iraq: 40 54 other. 15 34 *The Tigris and Euphrates both flow from headwaters inTurkey;they join to form Shatt% runoff Al-Arab about200 km (river kilometers)from Persian Gulf Turkey: 88-98 40 2-12 *Tigrishas several major tributaries draining Zagros Mtns along Iraq-Iran border Syria: Iraq: 0 51 other. 9 Climate *Precipitation mostly inwinter,much assnowfall,and most in mountainsof Turkeyand Zagros Mountains *Average annual precipitation varies from less than 100 mm in muchof Iraq to 1000-1600mm or more in the high mountainheadwaters Hvdroloffy *Average annual runoff exceeds80,000MCM/yr, the Euphrates generates about33,000 MCM/yr,the Tigris about20,500 MCM;the Tigris tributaries almost29,000 MCM , *Most flow from winter rains and spring snowmelt(50% offlows during 2 months); lowest flows are in late summer toearlyfall (September-October); Euphrates mean monthly low flow about 1/6th of mean monthly high flow CEWRC-IWR-P 29 May 91 *Flow varies markedly year-to-year, low record flows (since 1920s) are lessthan 1/3average annual *Lowest flow on record (atHit, Iraq) was 94cms (about1/10th averageannual discharge) *The Tigris, during floods, can carry a 20,000 ppm silt load (5x Nile flood load); only a tenth carried past Baghdad reaches the Persian Gulf Water Quality *Headwaters are generally high quality, but lower Euphrates (and Shatt al-Arab) is prone to salination *Sixty-eights % of Iraq's irrigated lands areaffected by salinityproblems Population *Iraq has greatest population within basin (15,600,000) *All three countries have growth rates that will doubletheirpopulation within 35 yrs. *Both rural settlements and urban population are growing, but the cities are growing at a much faster rate *The largestcities inregion are Baghdad (3-4 million pop.) and Mosul (700,000), both on the Tigris; several other citiesexceed300,000population along the Euphrates; Aleppo is the largestSyriancity inthe vicinity of the Euphrates(1,500,000 pop.) Economy *Much of the population is involvedin agriculture,1/3rd in Syria andIraq, 1/2 in the basin in Turkey Water Use *Withdrawalsfor irrigationis predominant water use accounting for more than 80% in Syria and Iraq *Euphrates and Tigris(andtributaries) irrigate more than 1 million and 2 million Ha in Iraq,respectively *While Syria and Turkeyhave much lessirrigation,both have ambitious irrigation reclamation programs * As citiesgrow and modernize, per capita consumption is increasing, e.g., Mosul, Iraq is projected to increase from230 liters/capita/day to 330 l/c/d (1974 to 2000) * Iran's most expensive urban water supply project is probably Baghdad's $6.6 millionintegratedsupply and sanitationprogram;the city's population is expected to increase to 5.5 million by the year 2000 *Iraq's urban population is supplied mainly from surface waters Water Development Plans *All three countries have programs that call for increased water use Turkey * SoutheastAnatolia Project (GAP) has hydropowerand irrigation works underway.GAP doesnot include Keban Dam(compl 1974) * GAP (13projects) will irrigate about 1 million hectares in both theTigrisand Euphrates basins *With completion of Karakaya(compl1987) and Ataturk (1990), the three upstream dams (Keban included) have almost90,000 MCM storage (approx 42,000 MCMlive storage), more than 2.5 X average annual Euphrates flow; smaller dams are also underway, on the main stem and on tributaries * Tigrisdams and projects are on longerschedule forcompletion; no dams in place yet * GAP will boost Turkey's total electric supply by80%, important since it is oil poor Syria *Tabqa Dam (a.k.a. EuphratesDam,Al-Thawra) impoundsLakeAssad and is centerpiece of its power supply and source for a hoped-for vast reclamation program for irrigation * Aleppodepends onLake Assad formunicipal, industrial and irrigation needs(200 k Ha projected) *Initial plans werefor 600kHa irrigated, but after more than a decade, the projected outputs have been scale wayback; gypsum soils easily taken into solution from canal seepage, among other problems * Irrigationplans nowcall for 200-300 kHa(includingKhabur Riverdevelopment) and offstream projects; more dams are planned on theKhabur forirrigating50 to 140 kHa Iraq * A storage construction and irrigation improvement program is underway *Several dams have been constructed on both the Tigris (and tributaries) and Euphrates in the last 10 years, for hydropower, flood flow regulation, and irrigation *In 1974, Iraq started a program to line its irrigation channels and networks and apply modem irrigation techniques; the 1980s saw first substantial expansion of their irrigation system 2 CEWRC-IWR-P 29 May 91 * A very important feature is a linkage of the Tigris to the Euphrates (via the Tharthar depression and canal), to alleviate expected shortages on the Euphrates, to alleviate flooding along its most intensely irrigated lands, and to drain salts from the region in between the two rivers *In addition, Iraq has constructed the Main Outfall Drain, 500 km long to drain about 2 million hectares of irrigation waters; the drain empties into the Shatt al-Basra Projected Water Use *All three countries project increased water withdrawals commensurate with their urban development, population growth, and increased irrigation development and hydropower (especially Syria and Turkey) * Manyfutureprojectionsfor withdrawals show substantial depletion, especially in the Euphrates; full developmentof GAP andmodest developmentofSyria's plans indicate that Iraq will be hard hit to meet its own irrigation needs on the Euphrates *While the Tigris is thought to have more water and be less susceptible to depletions, full development of water projects will impact the Tigris *Both Syria and Iraq likely will not be able to meet their needs during low flow years, (unless upstream reservoir carryoverstorage is released) * Approximately 10%of Euphrates annual flows will be lost via evaporation from Turkish reservoirs alone; Euphrates basin irrigationin Turkeymay consume another30 to 40% when allprojectcome on line *While full impactsof water quantitydepletion may not befeltfor some time,water quality impacts likely are close at hand; in the future, total agricultural return flows may account for more than1/2 of flows to Iraq via the Euphrates *Iraq's problemwith already saltywaterswill only by furtherexacerbated, and they have spent much to increasetheir irrigatedagricultural output through developing drainage systems *The Khabur River (Syria) will be heavily inundated with irrigation return flows, originally diverted off- stream from Ataturk to the Urfa-Harran-Mardin Plain; this area is the upper watershed for the Khabur and Belikh Rivers; irrigation return flows may rival natural stream flow, even during "normal"runoff years; and, Syria has plans to intensively irrigate thisarea(known as the High Jezira) Competition for Water *Syria and Iraq have not agreed to Turkey's minimum flow (500 cms) suggestions *Syria believes Ataturk will cut Euphrates flow by 2/3 *Syria and Iraq consider the Euphrates River to be "international" while Turkey points to the "transboundary" nature of the river *Iraq and Syria almost clashed in 1975 when both Keban and Tabqa dams filled coincidentally, virtually cutting off Euphrates flows. Recent Efforts to Resolve Conflict * 1980 - Establishment of a tri-national Joint Technical Committee (JTC) for information exchange and to seek ways for more
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