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Ilisu Dam And Hepp, Investigation Of Alternative Solutions

Congress: 2015
Author(s): Emrah Yalcin, Sahnaz Tigrek
Middle East Technical University1

Keyword(s): Sub-theme 10: Management of water resources,
AbstractEmrah Yalcina,*, Sahnaz Tigreka

aDepartment of Civil Engineering, Middle East Technical University, 06800 Ankara, Turkey

*Corresponding author Emrah Yalcin

Introduction The Ilisu Dam and HEPP Project, located on the Tigris River in South-eastern Anatolia Region of Turkey, has been under the debate more than half century due its possible adverse effects on the environment. Especially, the inundation of the archaeological sites around Hasankeyf has been receiving loud criticism from national and international platforms. On the other hand, Ilisu Dam has been defended by the government and governmental agencies on two bases. The first one is the increasing need for local energy sources and the second; it is one of the primary components of the South-eastern Anatolia Project (GAP). The flow regulation capacity of the Ilisu Project enables Cizre Dam to supply water for the Silopi and Nusaybin-Idil-Cizre irrigation schemes that cover an area of 121000 ha [7, 10]. Up to now, not a few articles and reports reviewing the project's environmental, social and economic impacts have been presented by scientists, unions, nongovernmental organizations and professional associations [1-4, 6, 8, 9, 12, 14]. However, a technical solution that would minimize the effects of Ilisu has not been developed considering continuing construction on the dam axis. This study is an assessment of a hydraulic solution not only rescues Hasankeyf with countless ancient monuments from inundation but also supplies the foreseen energy production of the Ilisu Dam and HEPP Project.
Methods/Materials In this evaluation, there are two constraints that could not be changed. Firstly, there has to be a dam on the existing axis in the alternative formulation because of the continuing construction works. Secondly, all the upstream projects such as dams and weirs which are in operation, in construction or in planning stage have to be considered while designating locations and maximum water levels of any alternative schemes. Within the context of these constraints, the crest elevation of Ilisu Dam was lowered from 530 m to mean elevation around the historical town, 459 m [13]. This decrease in the maximum water level of the project is ample to rescue the monuments from inundation. After that, other alternative dam locations providing the largest possible storage with the smallest possible fill volume were searched in the narrow valley sections at the upstream of Hasankeyf and the upper tributaries of the Tigris River. Thus, a hydraulic solution composed of five dams on the Tigris River and its branches was developed as a result of the conducted hydro-meteorological, water potential, flood analysis and optimization studies together with considering the topographical and geological characteristics of the proposed dam sites. The primary reason of the administration's insistence on construction of the Ilisu Dam and HEPP Project is its energy production capacity. This capacity was officially declared as 3833.5 GWh/year, composing of 2459.4 GWh/year firm energy and 1374.1 GWh/year secondary energy. However, this calculation was made under the existing upstream conditions at that time that only the Devegecidi Project, the Batman Diversion Scheme and some minor local irrigations were in concern [11]. Today, by means of the rapid development of the upstream watershed with the projects developed by incorporated companies in addition to the planned and operated schemes of State Hydraulic Works (DSI), there are 29 dam and 8 pond projects that are supposed to supply irrigation and domestic water together with hydroelectricity [5]. All those additional activities in the upstream of Ilisu will affect the energy production directly. After construction of these projects, while the presence of reservoirs will increase the firm energy ratio in production due to rise in the regulated inflows, there will be a considerable decrease in the total energy production because of the irrigation and domestic water abstractions. Therefore, the announced capacity of this project is not realistic if one considers the full upstream development. In order to re-calculate the foreseen energy production of Ilisu Dam and investigate the energy potential of the five-dam system, a joint operating policy was formulated at each branch for the stage corresponds to full development of the irrigation and domestic water supply schemes in the Tigris Basin.
Results and Discussion . It was seen in this study that there is no possibility of producing 3833.5 GWh/year energy by means of the Ilisu Project for the stage corresponding to full development of the upstream watershed. While the existing project has an energy production capacity of 3094.3 GWh/year, the proposed one is capable of providing 3139.1 GWh/year with a smaller installed power, in spite of a slight decrease in the produced firm energy. Although there is a 10014.6 hm3 reduction in the storage due to decrease in the crest elevation of the existing project from 530 m to 459 m, the reservoir volume becomes 4426.1 hm3 together with other four dams. This storage appeared ample to enable Cizre Dam to supply water for the Silopi and Nusaybin-Idil-Cizre irrigation schemes. The minor differences in terms of water usage ratio and firm energy against a 54 percent decrease in the active storage illustrate the effect of upstream dams on flow regulation and the needlessness of such an enormous reservoir.
Conclusion Moreover, if the whole basin is re-evaluated with an integrated basin management strategy instead of optimizing projects in themselves, different solution opportunities can be provided. Although it is obvious that an optimized basin model is just a mere imagination because of the projects developed by incorporated companies within the elevation allotment policy of DSI, a catchment-based operation optimization can be applied. 1. Balfour Beatty. (2001). Balfour Beatty withdraws from Ilisu Dam Project: No clear prospect of resolution of environment, commercial, and social complexities. Retrieved from (accessed 15 October 2009).
2. Basgelen, N. (2006). A unique global heritage starting to count its remaining days: Hasankeyf and Tigris Valley. Archaeology/Monument-Environment, 17, 114-119.
3. Bosshard, P. (1998). The Ilisu Hydroelectric Project (Turkey): A test case of international policy coherence. Berne Declaration. Retrieved from (accessed 3 May 2010).
4. Doga (Doga Dernegi). (2006). Review of the environment impact assessment report submitted for the Ilisu Dam and Hydro-Electric Power Project. Ankara:Doga Dernegi.
5. DSI (General Directorate of State Hydraulic Works). (2010). Retrieved from (accessed 23 May 2014).
6. Eberlein, C., Drillish, H., Ayboga, E., & Wenidoppler, T. (2010). The Ilisu Dam in Turkey and the role of export credit agencies and NGO network. Water Alternatives, 3, 291-312.
7. GAP (The Southeastern Anatolia Project Regional Development Organization). (2010). Retrieved from (accessed 15 May 2014).
8. Gumus, B., Dalkilic, N., & Toprak, Z. F. (2006). Ilýsu Barajý ve HES'in çok yönlü olarak deðerlendirilmesi [Multidimensional evaluation of Ilisu Dam and HEPP]. Diyarbakir: Dicle University.
9. Hildyard, N., Tricarico, A., Eberhard, S., Drillisch, H., & Norlen, D. (2000). If the river were a pen... the Ilisu Dam, the World Commission on Dams and export credit reform. London: The Corner House.
10. Ilisu Environment Group. (2005). Ilisu Dam and HEPP environment impact assessment report with enclosures. Ilisu Environment Group: Hydro Concepts Engineering, Hydro Quebec International and Archeotec Incorporated.
11. Ilisu Hydropower Consultants. (1983). The Cizre Dam and HEPP Project feasibility report. Ilisu Hydropower Consultants: Binnie & Partners, Gizbili Consultancy Engineering, James Williamson & Partners, Kennedy & Donkin and COBA.
12. KHPR (Kurdish Human Rights Project). (1999). The Ilisu Dam, a human rights disaster in the making, a report on the implications of the Ilisu Hydroelectric Power Project. Batman: Kurdish Human Rights Project.
13. Olus, M. A. (2003). Hasankeyf: üç dünyanýn buluþtuðu kent [Hasankeyf: a city three worlds meet] Istanbul: Is Kultur Publications.
14. Ongur, T. (2006). Ilisu Baraji kusurlu bir projedir [Ilýsu Dam is a defective project]. Retrieved from (accessed 18 May 2009].
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