Evaluation of underground dams in the Central Anatolian closed basin

This thesis examines the applicability of subsurface dams, an alternative water storage method, in the Central Anatolia Closed Basin in the face of the growing global water crisis. Turkey's annual average precipitation is 643 mm, which remains below the global average. The country's annually available freshwater potential is approximately 112 billion m³, while the per capita water availability is about 1,300 m³. These indicators reveal that Turkey is among the countries experiencing significant water stress. Within the scope of this research, the definition, historical development, construction techniques, and application areas of subsurface dams were evaluated. In particular, under the "100 Subsurface Dams Project" initiated by the General Directorate of State Hydraulic Works (DSİ) in 2019, it was determined that by 2023, 88 dams had been completed, providing the storage of approximately 30 million m³ of water and enabling the irrigation of nearly 150,000 decares of agricultural land. These findings demonstrate the considerable potential of such structures for enhancing agricultural productivity and water management. Assessments conducted in the Central Anatolia Closed Basin show that the region's annual average precipitation ranges between 350–400 mm, and aquifer levels have declined by 10–12 meters over the last two decades. Furthermore, about 25% of Turkey's irrigated farmland is located in this basin, highlighting the region's increasing dependence on water resources. Geomorphological and hydrogeological analyses in Çankırı, Ankara, and Kırıkkale indicate that the basin possesses favorable conditions for the construction of subsurface dams. In conclusion, it is suggested that with appropriate site selection and effective management strategies, subsurface dams can be expanded as a sustainable, cost-efficient, and environmentally friendly alternative within Turkey's water management system.