Iraq is generally divided into three river basins: the Tigris, the Euphrates, and the Shatt Al-Arab. The average annual flow of the Euphrates as it enters Iraq is estimated at 30 km3 and that of Tigris at 21.2 km3. While 50% of the Tigris water comes from within Iraq, more than 90% of Euphrates water comes from outside the country. Unlike the Euphrates, the Tigris has few tributaries all located on its left bank including the Greater Zab which generates 13.18 km3 at its confluence with Tigris, the Lesser Zab which generating 7.17 km3, the Al-Adhaim generating 0.79 km3 and Diyala river generating 5.74 km3. The total length of the running rivers in Iraq is about 4,773 km, with the Tigris and Euphrates accounting for 1,290 km and 1,015 km, respectively.
The gross irrigation water requirements, estimated at 75 billion m3 annually, are usually supplied from surface water resources, namely the Euphrates and Tigris rivers and their tributaries. In order to increase the water transport efficiency, minimize losses and water logging, and improve water quality, the Saddam River was constructed. the river functions as a main out-fall drain collecting drainage waters between the two main rivers the Euphrates and the Tigris for more than 1.5 million ha of agricultural land from north of Baghdad to the Gulf. It has a watercourse of 565 km and a total discharge of 210 m3 per sec. Other watercourses were constructed to reclaim new lands or to reduce water logging. Major watercourses are also under construction including East Al-Gharraf Drain and Tigris East Drain originating from south of Hila and south of Al-Kut respectively; both ending in Nasseriyah.
The recent severe shortage in rainfall in the basin areas of Iraq's major rivers and lack of snow cover over the catchments areas of these rivers, in addition to the reduction in water released downstream from dams constructed in the riparian state in Turkey has altogether diminished the volumes of water flowing in the Iraqi rivers. The total flow in all Iraqi rivers recorded during 98/99 and 99/00 was about 40% of the general total average. Consequently, irrigated cropping areas were diminished for the two growing seasons with production and productivity severely affected.
Good quality subterranean water has been found in the foothills of the mountains in the north-east of the country at 5-50 meters depth, where the aquifer discharge is estimated at about 10 to 40 m3/sec, and was also found in the area along the right bank of the Euphrates at a depth up to 300 meters. The estimated aquifer discharge stands at 13 m3 per sec. In other areas of the country groundwater is also found, but always with a salinity level higher than 1 mg/l. The salinity of aquifers on the right bank of the Euphrates River varies between 0.3 and 0.5 mg/l, while water salinity increases towards the south-east of the country reaching about 1 mg/l.
Currently, ground water resources provide an estimated 0.9 billion m3 of water annually covering the needs of 64,000 ha of agricultural land in areas where traditionally surface water resources are not available or supplemented by ground water supplies, namely in the Governorates of Al-Anbaar, Ninewa, Tameem, Salah El-Din, Kerbela'a, Najaf, Samawa and Basrah.
Thousands of deep wells have been drilled so far, by the State Company for Water Wells Drilling, at rural sites where the surface water network is not available. The wells are of multi-purpose and used for supplementary irrigation in winter, irrigating the vegetables in summer, watering the livestock and for domestic needs. Most recently, 1500 wells of up to 15 l/sec capacity each have been drilled in Ta'meem governorate alone. Other batteries of deep wells are drilled to supply water directly to both urban and rural population such as those in Condos (Ta'meem) and Qarah Tuba (Diyala).
Almost 70% of the country's cultivated area is under irrigation while the remaining 30% are under rain fed cultivation. In some areas supplementary irrigation is used to complement rainfall, the entire natural rangeland relies solely on rainfall. Of the areas under irrigation, 62.8% receives water through gravity irrigation projects, 36% pumped from rivers and major channels and 1.2% from ground water aquifers and springs.
The total irrigated area during the period from 1995 to 1997 ranged between 3.055 to 3.404 million ha, accounting for 30.6% of the total arable land, and 73% of the medium-to-high suitable land. The main irrigated crops are wheat, barley, rice, maize, vegetables and dates. The Tigris and Euphrates rivers have exerted a significant influence in the evolution of agricultural zones in Iraq. For instance, the estimated irrigation potential was increased by 29.41% from 1976 to 1990, which has been attributed to the development of water storage facilities for water received from the two rivers. In 1990, 63% of the irrigated land was in the Tigris basin, 35% in the Euphrates basin, and 2% in the Shatt Al-Arab basin. The latter refers to the part of downstream of the confluence of the two rivers.
A comprehensive network of sub-surface tile drains and surface drainage canals collect the drainage water from the agricultural fields and dispose it through the Saddam River's main out-fall drain to the Shat Al-Arab, thus keeping the irrigated lands free of salinization and water logging problems. Drainage water pumping stations are used to lift the effluent water to the main out-fall and onwards by gravity to the Arabian Gulf. Almost all land reclamation and development projects contain both irrigation and drainage components.
It is vital that adequate water supplies are ensured, through the development and management of Iraq's surface and ground water resources. Regular maintenance of existing irrigation infrastructure, construction of new irrigation schemes and emergency repair to any irrigation facility that might be damaged during an advent of war should all be catered for in a short term plan. In addition, special attention should be given towards undertaking precautionary measures for ensuring sustainable water supplies for irrigating the crops, watering the livestock and for domestic use in case of any future droughts. Interventions required could be concentrated on:
Maximum utilization of the available surface and ground water supplies. Efforts undertaken to achieve this goal required the rehabilitation of those old and worn out water pumping units and electric motors at irrigation and drainage pumping stations, and drilling and developing the tube wells in areas depending on ground water resources.
Minimizing water losses in the water channels conveyance networks. This involved proper cleaning of irrigation and drainage networks from weeds and sediments, routine cleaning of sub-surface tile drains, concrete lining of selected earth canal.
Improving the efficiencies of water diversion, conveyance and on-farm irrigation water application. This could be achieved through the regular maintenance of water diversion and distribution structures and equipment while constructing new ones, expansion in land reclamation suitable for surface irrigation as well as introduction of modern overhead sprinkler irrigation and localized drip irrigation systems at farmer's fields.
Iraq has an extensive and well-established irrigation infrastructure. The Ministry of Irrigation through its 17 affiliated State Companies and Commissions has constructed these facilities. Huge dams such as Derbandikan, Doukan, and Saddam are used for hydroelectric purposes; other smaller ones such as Dahouk, Dibbs, and Hamreen are used for irrigation water storage. Diversion structures such as Sameraá, Hindiyah, and Samawa are used to check the water flowing in the main rivers and divert it into main canals and distribution networks. Numerous pumping stations at rivers side with capacities up to 12 m3 per sec deliver water directly into water treatment plants, such as Diyala plant, or irrigation canals and onwards by gravity to farmer's fields. Interception or delay action dams such as Obayed, Khowlan are used to harvest rain water and use it locally for farming communities need. Irrigation and land reclamation projects are mainly scattered all over the centre and south region of Iraq. There main aim is to increase the cultivable and irrigated land area for sustainable agricultural production.
All Incoming irrigation inputs are received at eleven central distribution points warehouse stores of State Companies and Commissions of the Ministry of Irrigation in Baghdad. These are:
state company for machinery and equipment repair located in Doura;
state company for water wells drilling located in Al-Khadra;
al-nasr state company for irrigation projects maintenance located in Owaireej;
state commission for irrigation projects maintenance located in Saqlawiyah;
state company for water wells drilling located in Jarf al-Naddaf;
al-furat state company for irrigation projects studies and designs located in Al-Ameriyah;
state commission for dams and reservoirs located in Tel Mohammed;
Al-Qadissiyah state company for irrigation projects maintenance located in Zeidani;
Al-Fao state company for irrigation and reclamation projects located in Al-Shila'a;
Al-Rafidain state company for dams construction located in Al-Taji; and
state commission for irrigation and reclamation projects located in Mjaileh.
From the central warehouses, inputs are distributed to 16 affiliated state companies and commissions with head offices in Baghdad. These are listed below:
state commission for irrigation projects operation;
state commission for Saddam River operation;
state commission for dams and reservoirs;
state commission for irrigation and reclamation projects;
state commission for survey;
Al-Furat state company for irrigation projects studies and designs;
Dijla state Company for Irrigation Projects Studies and Designs
state company for water resource & soil researches;
state company for water wells drilling;
Al-Faw state company for irrigation and reclamation projects;
Al-Qadissiyah state company for irrigation and reclamation projects;
Al-Hadba' state company for irrigation projects maintenance;
Al-Nasr state company for irrigation projects maintenance;
Al- Fafidain state company for dams construction;
state company for machinery and equipment repair; and
Al-Muthana state company for rivers dredging.
After completion of the irrigation projects, all are handed to the ministry's 15 Directorates of Irrigation for follow up maintenance and operation. These directorates are based in the capital city of each governorate including Ninewa, Tameem, Salah Al-Deen, Diyala, Anbaar, Baghdad, Babylon, Kerbalaá, Najaf, Qadessiya, Muthana, Thi Qaar, Kut, Samawa and Basrah.
On the other hand, the Ministry of Agriculture is entrusted with providing farmers with small size booster pumps to lift the rationed surface irrigation water from nearby canals and rivers or open surface wells onto their flood irrigated fields. In addition, the Ministry of agriculture is also entrusted with providing individual farmers with on-farm irrigation equipment such as overhead irrigation sprinkler systems and localized drip irrigation systems. Thousands of centre pivots, linear moves, big boom guns, portable sprinkler irrigation systems and localized drip irrigation systems have already been provided to farmers for efficient on-farm water application through the Ministry's state Agriculture Supply Company.
Prior to the Gulf War in 1990, Iraq had one of the highest per capita incomes in the region and was able to import large quantities of food, medicine, agricultural items and other inputs that covered a large portion of its local requirements. But under the sanctions Iraq's ability to earn foreign currency needed to import essential inputs were severely constrained. Thus, many sectors were seriously affected including the agricultural sector, with production and productivity plunging to a low level and consequently critical shortages of food were experienced all over the country.
Under the Oil-for-Food programme, FAO has provided a considerable contribution to the rehabilitation of the Water Resources and Irrigation sector. On the basis of a comprehensive groundwater assessment, and using drilling equipment procured under the programme, a programme for sustainable exploitation of the groundwater resources is being implemented. Simultaneously traditional surface irrigation schemes are rehabilitated and upgraded, while water-saving irrigation equipment is being introduced to the small farmers and returnees. At present, about 90 to 100,000 HA are under irrigation.
In the Centre/South of the country, responsibilities for irrigated agriculture are shared by two Ministries. Water resources development as well as construction, maintenance and operation of the irrigation infrastructure falls under the Ministry of Irrigation, whereas the Ministry of Agriculture is responsible for on-farm irrigation. Observer reports of the irrigation and machinery sub-sectors in the South show that over 1.5 billion US$ of equipment have already been supplied through the UN Oil-for-Food Programme. Major procurements for MOI include replacements for worn-out components of irrigation and drainage pumping stations, heavy machinery used for canal cleaning (drag lines, dredges), earth movement and construction equipment (excavators, scrapers, shovels, bulldozers, graders, trucks, concrete plants, etc.), irrigation machines for 40,000 HA, well drilling equipment (drilling rigs, casing pipes), deep well pumps etc. Under the MOA programme almost 50,000 irrigation pumps and 10,000 irrigation systems (centre pivot, sprinkler) have been procured. Large amounts of spare parts were also provided.
About 70% of the funds allocated for the agriculture sector under the Oil-for-Food Programme were earmarked for the procurement of irrigation equipment for both the rehabilitation of the irrigation infrastructure and for the on-farm irrigation equipment requirements for farmers. To date, almost 82% of the inputs that arrived in Iraq under the "Oil-for-Food" program were equitably distributed among all regions of the country and were effectively utilized for the rehabilitation and maintenance of the irrigation projects.
Agricultural production in major parts of Iraq relies heavily upon irrigation. Thus the existing governmental irrigation projects are extremely important particularly in the centre and southern Iraq. In these regions a large part of the population depends on water supplies from the projects for irrigating the crops, watering the livestock and for domestic use. Therefore, it is vital that adequate water supplies are ensured, through regular maintenance of the existing irrigation infrastructure, and through the emergency repair to any irrigation facility that might be damaged during the war. The following are some measures to achieve this objective:
maintenance of water diversion equipment at head works structures;
rehabilitation of pumping units at irrigation and drainage pumping stations;
cleaning of irrigation and drainage surface conveyance networks from weeds and sediments;
dredging of rivers intakes to pumping stations and other water channels;
maintenance of water distribution facilities at canal networks;
excavation of new irrigation canal networks and concrete lining of existing earth canals;
routine cleaning of sub-surface tile drains;
laser land levelling for surface irrigation systems;
introduction of efficient overhead sprinkler irrigation systems for field crops at farm level;
introduction of efficient localized drip irrigation systems for vegetable crops and fruit trees;
drilling and development of deep wells in rural areas;
provision of deep well pumps and generating sets for wells at farmers fields;
construction of new delay action storage small dams at potential watershed sites;
completion of the main Saddan River section between Nasseriyah and Basrah;
completion of the storage dams currently under construction including Makhool, Al Adheem and Al Tharthar dams; and
completion of all land reclamation projects already started in the 15 center and southern Governorates including Al Haweejah, East al Gharraf, Hor Rajab, Lattiffiyah, ...etc.
Any serious damage to the country's dams (in both North and South/Centre) would seriously jeopardise agricultural production. Reduction of the dam storage and flow regulation capacities would result in reducing the irrigated area, increase flood risks and erosion problems, and in some cases affect hydropower production. Effects would be long lasting, as repair would be difficult, expensive and time-consuming. It would involve major contracts with specialised companies.
Any serious damage to weirs, canal intakes, headwork of irrigation systems would have serious effects on the downstream command area by reducing or cutting the irrigation flow, or provoking canal siltation. Effects would be less or longer lasting, and more limited in space and time. Damage to canal sections or bunds could temporarily disrupt irrigation activities. However, repair works should not be too complicated and would not involve very special equipment. Lack of maintenance on the canals (desalting, dredging) would result in reducing the irrigated areas, flooding, etc. Damage to drainage infrastructure would increase water-logging and salinity problems.
It is assumed that many of the major pumping stations for water supply as well as for drainage are operated by electricity-driven low head / volumetric pumps. Apart from direct damage to the pumping stations, irrigation or drainage would thus be disrupted in case of electricity cut-off.
Small size pump irrigation schemes (either groundwater or pumping from rivers) both in north and South / Central Iraq make use of diesel pumps or electric pumps + generators, and would thus be disturbed by fuel shortages. A large number of fixed central pivot systems are being installed in the Centre/South. They are delivered with pump and generator, and connected to deep wells. Their operation would equally be affected by fuel shortages.
Traditional small-size gravity irrigation schemes (North) would not be affected as long as farmers would stay in their fields.
Mechanical repairs and spare parts. Whereas in the northern Governorates, there is a constant supply of spare parts in the open market and private repair workshops are available, a possible conflict could have serious consequences in the Centre / South where repair facilities and spare part supplies are still partly organised through the State Companies.