Surface Water and Groundwater Resources in Turkey
Surface water
Turkey is divided into 25 basins that correspond with its hydrological features. Most rivers originate in Turkey and there are more than 120 natural lakes, 293 dams and 1,000 small dam resorvoirs.[1]Annual average flow in the basins is 186BCM. Possessing 28.4% of Turkey’s water potential, the Euphrates-Tigris River Basin is the largest basin in terms of both surface area and water potential.[2]
Groundwater
As mentioned above, Turkey’s total usable water potential is 112BCM, of which 98BCM is surface water and 14BCM is groundwater.[3] Approximately 20-25% of Turkey’s irrigable area is irrigated with groundwater. The share of groundwater use in industry is 48%.[4]
Groundwater resources are legislated by the Groundwater Law of 1962. In accordance with this law, groundwater resources fall under the jurisdiction of the state. The protection, research, registration and use of these waters are also covered by this law.[5] Every well has to be registered, but unlicensed well digging is hard to control. As in other places around the world, groundwater resources in Turkey are used for irrigation to a great extent.
Name of the Basin | Catchment Area (km2) | Mean Annual discharge (billion m3) | Contribution to total discharge (%) |
(21) Euphrates - Tigris River Basin | 184,918 | 52.94 | 28.4 |
(22) East Black Sea Basin | 24,077 | 14.90 | 8.0 |
(17) East Mediterranean Basin | 22,048 | 11.07 | 6.0 |
(09) Antalya Basin | 19,577 | 11.06 | 5.9 |
(13) West Black Sea Basin | 29,598 | 9.93 | 5.3 |
(08) West Mediterranean Basin | 20,953 | 8.93 | 4.8 |
(02) Marmara Basin | 24,100 | 8.33 | 4.5 |
(18) Seyhan River Basin | 20,450 | 8.01 | 4.3 |
(20) Ceyhan River Basin | 21,982 | 7.18 | 3.9 |
(15) Kizilirmak River Basin | 78,180 | 6.48 | 3.5 |
(12) Sakarya River Basin | 58,160 | 6.40 | 3.4 |
(23) Coruh River Basin | 19,872 | 6.30 | 3.4 |
(14) Yesilirmak River Basin | 36,114 | 5.80 | 3.1 |
(03) Susurluk River Basin | 22,399 | 5.43 | 2.9 |
(24) Aras River Basin | 27,548 | 4.63 | 2.5 |
(16) Konya Closed Basin | 53,850 | 4.52 | 2.4 |
(07) Buyuk Menderes River Basin | 24,976 | 3.03 | 1.6 |
(25) Van Lake Basin | 19,405 | 2.39 | 1.3 |
(04) North Aegean Basin | 10,003 | 2.90 | 1.1 |
(05) Gediz River Basin | 18,000 | 1.95 | 1.1 |
(01) Meric - Ergene River Basin | 14,560 | 1.33 | 0.7 |
(06) Kucuk Menderes River Basin | 6,907 | 1.19 | 0.6 |
(19) Asi River Basin | 7,796 | 1.17 | 0.6 |
(10) Burdur Lake Basin | 6374 | 0.50 | 0.3 |
(11) Akarcay Basin | 7,605 | 0.49 | 0.3 |
TOTAL | 779,452 | 186.86 | 100 |
Table 3. Catchment area and annual discharge of Turkey’s 25 river basins. Source: DSI 2014
In order to monitor groundwater extractions and prevent overuse, a groundwater measuring regulation was enacted in 2011.[8] Effective implementation of this regulation faces several challenges such as the existence of unlicensed wells, the difficulty of preventing illegal use of wells and changing climate and precipitation patterns. Despite these challenges, the regulation is a major step forwards in the protection and management of groundwater resources.
Name of the basin | Groundwater management reserve (MCM/year) |
(01) Meriç-Ergene Basin | 498.2 |
(02) Marmara Basin | 205.0 |
(03) Susurluk Basin | 585.1 |
(04) North Aegean Basin | 212.9 |
(05) Gediz Basin | 248.0 |
(06) Küçük Menderes Basin | 179.2 |
(07) Büyük Menderes Basin | 728.7 |
(08) West Mediterranean Basin | 316.7 |
(09) Antalya Basin | 526.3 |
(10) Burdur Lakes Basin | 89.5 |
(11) Akarçay Basin | 182.1 |
(12) Sakarya Basin | 1,535.7 |
(13) West Black Sea Basin | 412.2 |
(14) Yeşilırmak Basin | 579.0 |
(15) Kızılırmak Basin | 1,332.1 |
(16) Konya Closed Basin | 2,005.4 |
(17) East Mediterranean Basin | 70.5 |
(18) Seyhan Basin | 651.8 |
(19) Asi Basin | 304.5 |
(20) Ceyhan Basin | 533.5 |
(21) Euphrates-Tigris Basin | 2,789.2 |
(22) East Black Sea Basin | 435.6 |
(23) Çoruh Basin | 20.0 |
(24) Aras Basin | 204.0 |
(25) Van Lake Basin | 148.2 |
Total | 14,793.2 |
Table 4 – Groundwater Management Reserves [6]
Operating reserve | 14.7 billion m3 | |
Allocation | 13.5 billion m3 | |
Irrigation cooperatives TIGEM*, Recruitment to surface water | 4.11 billion m3 | |
Licensed utilization by private | 3.43 billion m3 | |
Municipal and industrial usage | 6.01 billion m3 |
*TİGEM: General Directorate of Agricultural Enterprises
Table 5- Groundwater operating reserve and allocation[7]
[1] ICOLD Large Dam Definition: dams with a height of 15m or more from the foundation of dams with a height 5-15 m having a resorvoir volume of 1hm3 or more
[2] DSİ, Water and DSİ, 2013, Ankara, p.21; FAO, 2009; Irrigation in the Middle East Region in Figures, FAO, Rome, p.358;
[3] Aysegul Kibaroglu, Annika Kramer, Waltina Scheumann (eds.), 2011, Turkey’s Water Policy: National Frameworks and International Cooperation, Springer, London, p.30
[4] Aysegul Kibaroglu, Annika Kramer, Waltina Scheumann (ed.), 2011, Turkey’s Water Policy: National Frameworks and International Cooperation, Springer, London, p.99.
[5] Yeraltı Suları Hakkında Kanun, Law on Ground Waters.
[6] Cengiz Sagnak, Ülkemizin Yeraltısuyu Potansiyeli, Kullanımı ve Sınıraşan Akiferler, 17 April 2013, Orman ve Su İşleri Bakanlığı, Hizmet İçi Eğitim, Akçakoca, Bolu.
[7] Cengiz Sagnak, Ulkemizin Yeraltısuyu Potansiyeli, Kullanımı ve Sınıraşan Akiferler, 17 April 2013, Orman ve Su İşleri Bakanlığı, Hizmet İçi EGitim, Akçakoca, Bolu.
[8] Official Gazette, 07 June 2011, , No. 27957, DSİ Yeraltısuları Teknik Yönetmeliğinde Değişiklik Yapılmasına Dair Yönetmelik.