Reducing Climate Impacts on Karst Groundwater Resources by Constructing a Cave Dam. A Case Study from Central Taurus Karst, Türkiye

Susuz karst aquifer is a mountainous and highly karstified aquifer located at the Central Taurus karst belt, Seydişehir, Türkiye. Pınarbaşı karst spring is a major water resource of the Susuz karst aquifer which drains approximately 15 million m3 of water annually, mostly between January and July. As the Pınarbaşı spring dries up for the rest of the year, local water needs frequently emerge during the dry periods, especially for animal livestock and domestic usage. However, one major problem in the karst region is the decreasing trend in the spring discharge rate and increasing length of the dry period mainly due to the impact of climate change. For this reason, to reduce the climate impact on the karst aquifer it is essential to explore alternative engineering solutions where they are applicable. This study proposes the construction of a cave dam in the Susuz karst system to retain and store groundwater during the dry period. Based on the accumulated hydrogeological knowledge and experiences in the karst region, we first conceptualized the cave dam construction and then indicated the positive influence of the stored groundwater under changing climate considering two main climate scenarios (SSP245 and SSP585). Our findings indicate that the (proposed) cave dam potentially stores 4 million m3 of water, which equals nearly 35 % of the mean annual spring discharge under current climate conditions while this amount is also expected to rise over 50 % of the total discharge in future climate conditions.