The Importance of Irrigation

  • The regions known as “cradles of civilization” have always been founded on the banks of rivers and close to water sources since ancient times. Throughout history, it has always been societies that have had the opportunity to benefit from rivers and streams which have established the most advanced civilizations of their era, and societies that did not have this chance had to migrate to other places, leaving their lands when they faced droughts. Ancient inscriptions and relics prove that the first civilizations founded cities in ancient Mesopotamia, today known as the “fertile crescent”, on the fertile lands between the Tigris and Euphrates rivers, where the world’s very first inscriptions were discovered and agriculture began. Mesopotamia owes this position to the abundant waters of the Tigris and Euphrates. It is believed that in 3000 B.C., the Tigris and Euphrates rivers were connected to each other by a canal system constructed by the Sumerians, who benefited from these rivers more functionally.

  • Since fresh water resources are not sufficient to meet the increasing demands of world population, water is regarded as a strategically important commodity. In the future, the most important factor affecting the use and quality of water resources will be population. In 2000, the world population was 6 billion and it is estimated that it will be 8.3 billion by 2025. In other words, the world population will increase 35% by 2025. Total annual food production in the world today seems to be on a satisfactory level in terms of meeting world food consumption needs. However, there are differences in the amount of food production per capita among the regions of the world. In developed countries, less than 7% of the general population is active in the agricultural sector, and a farmer and his family, besides thei own needs, can meet the food needs of 50 people who are active in non-agricultural sectors. Nevertheless, in developing countries, more than half of the population is engaged in the agriculture sector, but a farmer and his family can provide for only 2 people.

    • Another function of the agricultural sector is to provide finance for economic development. The agricultural and industrial sectors have a mutual relationship in economic development. By demanding the produced inputs and consumer goods of non-agricultural sectors, developing agriculture helps non-agricultural sectors to develop. On the other hand, non-agricultural sectors help the agricultural sector to develop by demanding agricultural goods. Thus, the agricultural and industrial sectors are two markets that are in a bilateral relationship continuously and support each other mutually. Neither of the two sectors can be neglected in economic development.
    • Almost one third of Turkey’s total area (78 Mha) is arable land (28 Mha). Comprehensive studies pointed indicate that 8.5 million ha of the arable land is economically irrigable in Turkey. As of 2005, 4.9 million ha of an 8.5 million ha area have been equipped with irrigation facilities, this being 2.8 Mha developed by DSİ, 1.1 Mha developed by the GDRS, and about 1.0 Mha by small- scale privately owned irrigation schemes. Moreover, 6.5 million ha of 8.5 Mha land have been envisaged for development by DSİ, 1.5 million by other state agencies, and 0.5 million ha by small- scale privately owned irrigation schemes by the year 2030.
    • As of 2005, irrigation projects the total area of which is 2.8 million ha developed by DSİ constitute one third of total irrigable area (8.5 Mha) of Turkey. When we look at the figures achieved so far, DSİ’s development of 2.8 Mha means that 10% of the total agricultural area of 28 million ha and 57% of Turkey’s irrigated area of 4.9 million ha. are being irrigated. It is estimated that the irrigation area to be developed by DSİ by 2030 will increase to 6.5 million ha (76%) . Turkey, with its present irrigation development of 58% (4.9 Mha of 8.5 Mha), aims at reaching the 8.5 million ha which is technically and economically viable in today’s conditions in order to meet food requirements, to grow agricultural products for industry in a balanced, stable and continuous manner, to solve the unemployment problem of the population working in the agricultural sector, and to raise living standards. Thus, completion of the remaining irrigation projects of 3.6 million ha is of big importance for the above-mentioned purposes.

    Approximately 94% of the total area is irrigated by using surface irrigation methods such as furrow, border, and wild flooding. The remaining part is irrigated with pressurized irrigation methods, i.e sprinklers and drips. An area of about 200,000 ha is equipped with sprinkler irrigation systems consisting of portable pipes, which are widely used among farmers in Turkey. In DSİ irrigation projects, an area of more than 80,000 ha. has been irrigated by sprinkler irrigation (mainly for sugar beet, cereals, clover, sunflower, melon, and vegetables). 

    DSİ has developed a 11,000 ha area in which mainly citrus fruits, vineyards, strawberries, and vegetables are cultivated by using drip irrigation. Water is one of the most important inputs in agricultural development. It provides moisture for plants in the soil and thus increases yield, and also makes the agricultural sector free from climatic conditions, creates additional employment, improves income distribution in rural areas, makes fertilizer use possible, increases a variety of production, and results in yields of more than one crop, depending on the length of the growing period. By 2030, when areas equipped with irrigation infrastructure by DSİ will reach 6.5 million ha, it could provide additional employment for 2 million people. In addition to this economic contribution, irrigated agriculture halts migration to the big cities and brings about social benefit.

Irrigation Increases Per Capita GDAP (Gross Domestic Agricultural Product) approximately 5-fold

  • Irrigation increases GDAP (Gross Domestic Agricultural Product) approximately five times. According to 2004 data, agricultural income was 600 YTL (375 USD) per ha in pre-irrigation conditions. However, the figure is now 3,100 YTL (1,950 USD) per ha in post-irrigation conditions.
  • Realization and success of irrigation projects depend on various factors. Firstly, land has to be suitable for irrigation; secondly, the irrigation source has to be adequate and water quality has to be appropriate for irrigation. After these two main conditions, an irrigation scheme to convey water to the irrigation area for farmers’ use and a drainage system to take excess water away from the irrigation area has to be constructed. All these physical facilities have to be complete and perfect. However, these factors alone may not be adequate for successful irrigation. Since irrigation is a vigorous activity, success of irrigation depends on the knowledge and skills of farmers as well as good management by responsible authorities.

Priority Determination Criteria of Irrigation Projects

  • When preparing investment programs, DSİ evaluates prospective irrigation projects according to the following requirements:
  • Farmers’ demand for irrigation water;
  • Land fertility together with climatic suitability;
  • Water resource availability;
  • Type of water supply and transmission (gravity is preferred to pumping);
  • Completion of land consolidation works.
  • The first and crucial step in irrigation projects is that farmers’ comprehension of irrigation is expressed by forming an organization to demand irrigation schemes, together with participatory irrigation management by accepting the cost recovery of irrigation investments. The best examples of this step could be seen at Groundwater Irrigation Cooperatives (GWICs).
  • Fertile lands and suitable climatic conditions can give satisfactory results in obtaining more than one crop in the same year.
  • Dams may have more than one purpose, including flood protection, energy generation, irrigation, and domestic and industrial water supply. If the water source is a dam or a small dam, farmers will have safe and clean water throughout the irrigation season for their irrigated agricultural activities.
  • Gravity irrigation investment cost is cheaper than pumping irrigation investment cost, as well as less of a financial burden on farmers during the operation process since electricity costs account for the biggest share of operational costs. It even constitutes up to 80% of the budget of a Water User Organization (WUA) using a pumping irrigation system.
  • After land consolidation, optimal and efficient operation conditions could be provided since expropriation and other investment costs decrease in consolidated lands. Therefore, prepared areas in terms of land consolidation are preferred for irrigation investment.
  • Because of the high population growth rate and fragmentation of lands by inheritance, farms are continuously shrinking, and problems arise in obtaining the expected benefit from irrigation projects. To solve these problems, land consolidation activities performed by other institutions (GDRS and the General Directorate of Agricultural Reform) should be supported and harmonized with DSİ’s agenda. Land consolidation activities bring about efficient use of modern technologies in agricultural production, optimum construction of irrigation and transportation networks for agricultural lands, and legal prohibition of further division of land. Land consolidation eliminates expropriation costs and decreases construction, operation and maintenance costs to a large extent in irrigation projects. Due to continuously increasing agricultural land prices, expropriation expenses in some areas may be equal in cost to the project budget, or even more. The application of modern pipeline irrigation distribution systems providing technically and economically high standards in irrigation projects contributes considerably to the prosperity of farmers and the national economy.

DSİ’s Targets on Completion of Irrigation Projects

  • Recently, the state investment budget has decreased and so has the share of DSİ in this budget. Inadequacy and decline in public funding for irrigation projects have resulted in extended delays in completion of projects. Consequently, this may bring about the following: the expected benefit cannot b e obtained, trust in public agencies weakens, and some technical drawbacks may appear. A total of 169 large-scale irrigation projects which are included in the investment programme of DSİ can only be completed in 38 years with the budget allocated in 2005. The DSİ General Directorate aims to shorten this time interval to 20 years in the short term, even to 10 years by developing alternative financing models.

DSİ Irrigations and Canal Length

As of the beginning of 2005, DSİ has realized construction of 1,908 irrigation schemes and has thus equipped net 2,396,434 ha area with irrigation facilities in which DSİ operates an area of 113,158 ha (70 irrigation schemes), while it has transferred 1,860,969 ha (642 irrigation schemes) to Water User Associations (WUAs), and 15,766 ha (27 irrigation schemes) to other agencies (State Farms, Universities, etc.). Furthermore, an area of 406,541 ha (1,169 irrigation schemes) has been developed by GDRS in cooperation with DSİ for GWICs.

Irrigation Canal Types and Lengths (km) as of the Beginning of 2005 

  • As of 2005, in completed irrigation projects, canal types according to their service area are as follows: 45% classic open canals (unlined and lined), 48% canalettes, and 7% pipe systems. Canal lengths in the irrigation schemes of GWICs constructed by GDRS are not included in the above figures. A similar classification also can be made according to canal lengths.
  • Besides irrigation canals, open drainage canals constructed for taking away returning water from irrigation and excess water from the irrigation area are also operated by DSİ. Total drainage canal length is 20,716 km, 5,133 km of which is main drainage canals, 6,499 km secondary drainage canals, and 9,083 km tertiary drainage canals. In order to perform operation, management, maintenance and repair of canals, and to provide access for farmers, 38,278 km of service roads have been built. In all DSİ-developed irrigations, in order to perform operation, maintenance and repair of the above- mentioned canals, and ensure farmers’ participation, DSİ has adopted a new policy, and management responsibility for irrigation has been in the hands of farming organizations since 1993. The World Bank has supported the Irrigation Management Transfer (IMT) performed by DSİ. The IMT executed by DSİ has been so successful that the World Bank has shown it as an exemplary policy to developing countries .

Irrigation Management

  • About 80% of a gross irrigation area of 2,773,650 ha developed by DSİ has been irrigated by surface water sources, and the remaining 20% by groundwater sources. In order to realize the most appropriate agricultural production by using existing water sources in the most economical way, planned irrigation management works have been applied in these irrigations. Planned irrigation management works include preparing general irrigation planning before the irrigation season, preparing, applying, and monitoring water distribution programmes during the irrigation season, and evaluation processes after the irrigation season.
  • Investment costs as well as expropriation costs for DSİ-developed irrigation facilities are to be recovered by the beneficiaries pursuant to Law No. 6200. Up till now, cost recovery prices of investments have been determined by decree of the Prime Ministry. The most recent annual investment cost recoveries have been between 0.15 YTL -0.75 YTL/da according to Decree of the Prime Ministry of 7 th May 2001. The average repayment period is about 11 years.
  • Sediment accumulation and vegetation are two factors making water conveyance in earth drainage canals difficult. Mechanical control methods in particular are used to solve these problems.
  • One main element of irrigation management is to prepare the physical structures of irrigation facilities (hydraulic structures such as canals, checks, gauges heads, etc.) for irrigation before the season. For this purpose, the necessary maintenance and repair works (painting, canal cleaning, canal repairs, fitting fallen canalettes, waterproofing with bitumen, etc.) have to be completed..
  • Cereals are generally grown in rainfed agricultural areas but crop patterns vary and diversify greatly after irrigation. Crop patterns have been identified by recent studies in DSİ irrigation schemes as follows; 20% cotton, 19% cereals, 17% maize, 6% sugar beet, 6% vegetables, 3% legume, 6% fruit, 3% citrus, 3% sunflower, 3% forage crops, 3% vineyards, and 11% other crops. The crop yields with irrigation are shown as follows: cotton 384 kg/da, cereal 391 kg/da, maize 958 kg/da, sugar beet 5,329 kg/da, legumes 261 kg/da, citrus 3,968 kg/da, sunflower 236 kg/da, forage crops 1,055 kg/da. Yield increments of crops with irrigation are shown as follows: 137% for cereals, 151% for legumes, 70% for sugar beet, 212% for cotton, 416% for maize, 129% for fruits, 152% for citrus and 203% for vegetables.
  • Since water resources are scarce and different sectors increase water demands continuously for other purposes apart from irrigation, water- saving is required, especially in the irrigation sector, which accounts for the greatest share in water consumption. A typical example is the Southeastern Anatolia Project where long tunnels, expensive conveyance canals, and pumps at high altitudes to convey water to irrigation areas have increased the cost of the water so much that water- saving has become compulsory. Since water will be of greater importance in the future, it has to be used more carefully. The water amount consumed in one growing season is an average of 10,000 m³/ha in DSİ irrigation schemes.
  • Farm efficiency in traditional irrigation systems such as in border or furrow irrigations is about 60%. If leakage, evaporation, and operational losses are included, efficiency becomes 50%. In other words, to provide the necessary 1 cubic meter of water for a crop, 2 cubic meters of water are consumed, resulting in waste of limited water resources, construction of drainage schemes with bigger capacities, thus increasing costs, and additional power consumption if the system includes pumping.
  • Water efficiency is a very important issue in irrigation as well as other sectors. Since crop water requirements cannot be reduced to any great extent during irrigations, water- saving can only be achieved during water conveyance, water distribution, system operation and field water application. In order to use the water effectively, DSİ has shifted its policy from classic open- channel distribution networks to more water -saving systems. The proportion of pipeline distribution network has increased by up to 40% in projects that are under construction, while it is 6% in schemes already developed. In open canal systems, there are 10% operational (conveyance) losses consisting of 5% from main canals and 5% from branch canals. It includes evaporation, overflows and leakages. Decreasing these losses is of greater importance, especially in large irrigation schemes. Water savings increase in pressurized pipe networks. Because of this, closed pipelines are encouraged in modern irrigation systems. Furthermore, on-farm water losses constitute the major proportion of total water losses in irrigation, and the main source of losses are farming practices. Therefore, the most important factor is to increase farm efficiency. When sprinkler and drip irrigation methods are utilized instead of traditional methods, efficiency increases from 60% to 80-90% respectively. It means 20-30% water saving at on-farm level alone.

Irrigation Management Transfer (IMT)

  • Transfer of operation, maintenance, and management responsibilities of irrigation systems from DSİ to Water User Organizations (WUOs) has gained momentum since 1993. While small and isolated projects were being transferred before 1993, transfer activities began to include large-scale irrigation systems after 1993. WUOs assume the responsibility for operation rights of the project; they do not take the ownership rights away from DSİ.

Main Reasons and Targets of IMT


The Use of Water Resources in DSİ Irrigation Facilities
81% Surface Water Resources
13% Pumping
68% Surface Gravity
19% Groundwater Resources
3% DSİ Groundwater Irrigations (DSİ GWIs)
16% Groundwater Irrigation Cooperatives (GWICs)

  • Irrigation ratios and irrigation efficiencies are used in order to determine performance criteria of irrigation facilities. The irrigation ratio and irrigation efficiency have been 65% and 45% respectively. These average figures have been deduced from recent DSİ irrigation operations.
  • The reasons for low irrigation ratios can include the following: leaving the land to fallow (13%), adoption of rainfed cropping (28%), inadequacy of water resources (4%), insufficient irrigation structures (6%), high watertable (2%), salinity and alkalinity (2%), inadequate maintenance (2%), topographic conditions (4%), economic and social problems (22%), and other reasons such as occupation of agricultural lands for industrial and settlement purposes (17%). These figures have been obtained from irrigation networks of over 1,000 ha.developed by DSİ. Steps are being taken to increase irrigation efficiencies up to 50% in DSİ’s open canal surface irrigation systems.
  • To manage irrigation activities successfully, the following conditions must be observed:
  • 1:5000 scale operational maps;
  • The required number of trained staff;
  • The necessary machinery for maintenance and repair;
  • Estimation of water requirement of irrigation project before the irrigation season and making a comparison of the water demand with the water supply;
  • Transportation vehicles (cars, motorcycles, etc.); and
  • Communication means (wireless, telephone, etc.).
  • Law No. 6200 states that the whole of actual operation and maintenance expenditures incurred by DSİ for irrigation investments are subject to repayment by the beneficiaries as operation and maintenance charges (‘irrigation fees’ as farmers say). Operation and maintenance charges are determined each year by Council of Ministers’ decree. Law No. 6200 also authorizes the Council of Ministers to make discounts in operation and maintenance charges. Recent evaluations indicate that irrigation charges are about 3-5% of agricultural production values.
    • Decrease in budget and other assets;
    • The reality that users often perform services more economically, more systematically , and more swiftly
    • Similar approaches in the world.

    Targets :

    • Farmer participation and local management;
    • Sense of ownership; and
    • Self-control.

    Benefits :

    • Decrease in operation and maintenance expenditures (personnel, energy, maintenance, and repair costs);
    • More equitable, reliable, and adequate water distribution; and

    Solution of problems in each locality.


    Water User Organizations (WUOs)

    • WUOs can be in several forms. If an irrigation network goes through one local authority area, the management of the irrigation network can be transferred to that authority. However, the majority of irrigation networks go through more than one local authority area or serve more than one administrative unit. So they could be transferred to WUAs established according to Law No. 1580 and Law No. 442, and to Irrigation Cooperatives (ICs) established according to Law No. 1163. Irrigation schemes, which serve the area of only one administrative unit could be transferred to ICs, as well as to the Municipalities and Village Authorities. The transfer ratio of DSİ has reached 94%, which indicates the success of these transfer activities. This figure does not include the transfer of Groundwater Irrigation Cooperatives (GWICs), which were set up jointly by DSİ and GDRS. In GWIC groundwater irrigation schemes, well-drilling, electrification, and pumping are carried out by DSİ and irrigation schemes are completed by GDRS. 

    Participatory Privatization of Irrigation, Management, Investment Project (PPIMIP)

    • PPIMIP has been developed to make financial contributions for purchase of machinery and equipment needed by WUAs, which take over the responsibility for operation and maintenance services of irrigation facilities developed by DSİ. In order to benefit from the PPIMIP project, irrigation organizations have financed 60-80% of the purchasing value of equipment from their own sources, and then the PPIMIP project has supplied the remaining 20-40% finance of the purchasing value. 17 WUAs have performed modernization and rehabilitation, either in the whole or in some parts of their schemes on the basis of 50% participation in the cost. A loan of US$ 20 million, provided by the World Bank was used between 1998-2004.

    Groundwater Potential

    • Groundwater investigations have been carried out since 1956. According to the studies performed until 2005, the exploitable groundwater resources of Turkey are 13.66 km 3/year, excluding the discharge of springs feeding surface water resources. At present, 11.44 km 3/year of the groundwater reserve has been allocated, 6.24 km 3/year of which is for irrigation (including private use of 2.34 km 3/year) and 5.20 km 3/year of which is for domestic and industrial purposes.
    • Works relating to groundwater in Turkey are executed by DSİ on behalf of the State according to Groundwater Law No. 167. The number, location, depth, amount of pumping water, and other characteristics of wells that will be drilled are determined by DSİ. Borders, structures, and characteristics of groundwater areas are determined according to the 3 rd article of Groundwater Law No. 167. These areas are declared “Groundwater Operation Areas” by the respective Ministry, based on DSİ’s proposal. Searches for and use of groundwater (more than 10 m depth) inside and outside of proclaimed groundwater operation areas are subject to permissions given by DSİ according to the 8 th article of the same Law. In the same manner, permission documents for rehabilitation and alteration are also granted by DSİ.

    Groundwater Consumption

    • Groundwater in Turkey is used for domestic supply, industrial purposes and irrigation. Groundwater irrigation activities are jointly carried out by DSİ and GDRS.

    Groundwater Irrigations

    Groundwater irrigations can be divided into two types; State Supported Groundwater

    State Supported Groundwater Irrigations

    • These irrigations are performed in three types; DSİ Groundwater Irrigations (DSİ GWIs), Public Groundwater Irrigations (Public GWIs), and Groundwater Irrigation Cooperatives (GWICs).

    DSİ Groundwater Irrigations (DSİ GWIs)

    • These types of groundwater irrigations are developed mainly to supplement surface water irrigations constructed and operated by DSİ. There are also the groundwater irrigation facilities constructed and operated by DSİ using only groundwater. As of 2005, 78,145 ha area has been irrigated using groundwater. In recent years, the operating rights of most of these irrigations have been transferred to irrigation organizations.

    An Example of Groundwater Irrigation 

    Public Groundwater Irrigations (Public GWIs)

    • Public institutions, mostly Agricultural Enterprises, demand groundwater irrigation. For that purpose, groundwater wells are drilled and irrigation schemes are constructed by DSİ on the basis of cost payment (by DSİ). Operation of these projects is performed by the respective organizations or institutions. As of 2005, an area of 16,140 ha area has been irrigated by groundwater in 25 projects of public organisations, with 342 wells.

    Groundwater Irrigation Cooperatives (GWICs)

    • The irrigation area of GWICs constitutes the greater part of groundwater irrigations in our country. GWICs irrigations were established in 1966 in accordance with Law No. 1163 Regarding Cooperatives. There has been intensive demand for such schemes from farmers for the past 37 years. As a result, GWICs have multiplied. These irrigations were first launched by cooperation between DSİ and the Soil-Water General Directorate under the name of “Agricultural Irrigation, Soil Conservation, and Land Reclamation. Soil and Water Cooperative with Restricted Responsibility”. Later, in 1984, the Soil and Water Organization was abolished, and the General Directorate of Rural Services (GDRS) was founded. Subsequently, GDRS and DSİ together have continued these activities to develop the organizations known as “Irrigation Cooperatives with Restricted Responsibility”.
    • In order to encourage establishment of GWICs, to construct facilities and to perform activities, these activities have been realized according to Cooperation Protocol dated 3 rd .3. 1966 and to the Revised Protocol dated 31 st .12. 1973, which were signed by DSİ, the Soil-Water Organization, and the Agricultural Bank. DSİ’s duties are to realize preparation of technical and economic feasibility reports for facilities to be constructed by DSİ, drilling of groundwater wells, preparing projects for electrification facilities for wells, constructing wells and determining suitable pumping motor types for wells, as well as procurement and installment of suitable pumping motor types.
    • GWICs’ duties are to take over the responsibility of facilities constructed by DSİ, to perform maintenance and repair work, and to operate these groundwater irrigation facilities.
    • Small irrigation canal constructions and services provided by GDRS for GWICs are free of charge. However, the costs of well drillings, electrification of the wells as well as purchase and assembly of pump equipment, which are incurred by DSİ, are subject to repayment. The cost of facilities has been calculated with no interest, and the DSİ-prepared Transfer Agreement pursuant to the Decision of the Council of Ministers has transferred facilities to GWICs. The Transfer Agreement used to provide for a 30-year operational period, the first 5 years being a grace period, and the next 25 years with cost recovery. During this period, operational drilling wells used to be renewed once only, and pumping engines used to be renewed twice by DSİ. However, with a Prime Ministry Decree dated 26 th .06. 1997, the Transfer Agreement was amended. For facilities constructed after that date, cost recovery has been decreased to 15 years; the first 3 years being a grace period, and the remaining 12 years, a repayment period with equal instalments. Owners of facilities constructed before this date have legally retained prior rights and are exempted from the cost of well and pumping engine charges for renewals. For constructions realised after the above- mentioned date, wells and engines have not been renewed free of charge. If renewals are needed and requested by the GWICs, renewals can be done by way of cost return.
    • As of 2005, 406,458 ha area have been irrigated by GWICs. There are about 1,000 active GWICs in our country. These cooperatives are mainly concentrated in the Konya, Isparta, Eskişehir, Kayseri, Edirne, Samsun, and İzmir DSİ Regional Directorates.
    • Groundwater irrigation facilities are transferred to GWICs in accordance with Law No. 6200. As of 2005, 8,543 wells and their premises, constructed by DSİ and irrigating an area of 358,313 ha. have been transferred to a total of 1,577 GWICs.
    • As of 2005, a net area of 500,743 ha has been irrigated by groundwater from 11,778 wells by DSİ Groundwater Irrigations (DSİ GWIs), Public Groundwater Irrigations (Public GWIs) and Groundwater Irrigation Cooperatives (GWICs). The irrigation area of GWICs among the State Supported Groundwater Irrigations has the biggest share, with 80%.
    • The area of DSİ GWIs accounts for 20% of the total irrigation area of DSİ.

    State Supported Groundwater Irrigations by Years 

    Individual Farmer Groundwater Irrigations

    • Individual farmers are granted irrigation licences in accordance with the Law No. 167. As of 2005, 111,513 user licenses have been granted for individual irrigations and domestic and industrial water purposes. 2.23 km 3 of water has been allocated for individual irrigations.


    Southeastern Anatolian Project (GAP)

    • The Southeastern Anatolian Project (Güneydoğu Anadolu Projesi, or GAP), is a very important integrated project for the economic and social development of the Region. The project includes active farming with extensive irrigation systems and electricity generation.
    • The project area covers the lower parts of the Euphrates and Tigris Rivers and 9 provinces in the Region. These are Gaziantep, Adıyaman, Kilis, Şanlıurfa, Diyarbakır, Mardin, Siirt, Batman, and Şırnak. A total of 6.47 million people live in these provinces according to the population census held in 2000.
    • The project is one of the biggest investments of the last century undertaken by DSİ and contains 13 projects, 7 of which are in the Euphrates Basin and 6 of which are in the Tigris Basin.
    • Within the scope of these 13 projects, 27 billion kWh hydroelectric energy will be produced annually with 7,500 MW installed capacity and 1.82 million ha of land will be irrigated with the construction of 22 dams and 19 HEPPs. Within the GAP project, the level of realization of energy projects is 75% and that of irrigation projects is 12%.
    • The Karakaya, Atatürk, Birecik and Karkamış dams and HEPPs on the Euphrates River, and the Batman, Kralkızı, and Dicle dams and HEPPs on the Tigris River have been completed and hydroelectric energy is being produced in all HEPPs. The Hancağız and Çamgazi dams have also been completed on the Euphrates River, but these are without HEPPs.

    GAP Irrigations in Operation (ha)


    Euphrates Basin

    Şanlıurfa Harran-----------123,392

    Adıyaman Çamgazi----------2,000

    Hancağız---------------------- 6,945


    Individual Irrigations

    Nusaybin Çağçağ------------8,600

    Akçakale Groundwater----10,255

    Ceylanpınar Groundwater- 9,000


    Derik Dumluca---------------1,860

    XV. Region Small Scale------900

    XX. Region Small Scale----4,939

    Tigris Basin :

    Kralkızı-Tigris Pumping----4,758

    Individual Irrigations


    Silvan I and II-----------------8,790

    Silopi Nerdüş------------------2,740

    Çınar Göksu ------------------4,234

    Garzan Kozluk----------------3,973

    X. Region Small Scale ------3,258

    Grand Total 213,924 ha

    • Being an integrated development project, GAP aims to raise the income level of the Region and to affect socio-cultural development positively. The main factor that would increase the general income level will be achieved by means of the investments to be realized by DSİ, especially investments in the agricultural sector. For this reason, the Government has decided that GAP will be completed by 2010 and has announced this with Letter No. 98/11231 dated 04.06.1998, stating that all relevant organizations will revise their programmes accordingly. The DSİ General Directorate also conducted a study in this direction in 1998 to finish its own program by 2010, and the annual amount of budget required for the 1999-2010 period has been determined and submitted to associated organizations. However, it is clear from the amounts of the 1999-2004 period investment budgets that funds reserved for GAP are not sufficient to realize targets. If the above- mentioned target (2010) were still to be valid, an optimum annual construction amount would be taken into account and implemented accordingly.
    • Individual projects involving a total area of 110,485 ha are included within the total GAP irrigation area of 1,821,048 ha. Among these individual projects realized by DSİ Regional Directorates, 71,229 ha are in operation.

    Water User Organizations (WUOs)

    Name of the Organization


    Unit Rate (%)

    Area (ha)

    AreaRate (%)

    Village Authority