Hydrogeological and hydrochemical investigations of lake bafa: Sustainable water resource management

This study includes hydrogeological and hydrogeochemical assessment and investigation of the flow and contamination relationships between surface water and groundwater of the Lake Bafa and its western part. Menderes Massif rocks form the basis of the geological structure in and around the study area. Jurassic-Cretaceous marbles belonging to the Menderes Massif, overlying Neogene lacustrine carbonates and Quaternary alluvium are the aquifer forming units. Groundwater is exploited from many wells and springs. Lake Bafa and geothermal fluid with conductivity values of 23400 and 56000 µS/cm are Na-Cl dominated waters, respectively. Seawater mixing percentages have been calculated for saline waters. Lake Bafa is recharged by geothermal water affected by seawater intrusion, rainwaters and Büyük Menderes River. Low-temperature saline karstic waters supplied from the marbles belonging to the Menderes Massif in the northwest of the Lake Bafa are used by fish farmers in the region. Groundwater with about 2 m /sec is discharged to the Lake Bafa or Büyük Menderes River after usage. Processes, which determine the chemistry of the lake, are mixture of these water and effect of evaporation. The seawater intrusion is controlled by the Akköy Fault extending from the sea to the Lake Bafa. Salinity of the Lake Bafa is not a sign of contamination, but the result of natural geological evolution. However, geothermal waters containing high dissolved ions discharged into the Lake Bafa negatively affect the ecosystem of the lake. Geothermal waste water should be removed from ammonium and reinjected into the marble unit. This implementation has been determined as the most suitable method for the continuity of the reservoir and ecosystem. The suitability of the waters for drinking, livestock and fish farming has been examined. The surface water and groundwater relationship is determined in and around of the Lake Bafa, and the results are interpreted by evaluating organic-inorganic chemical analysis. Solution suggestions for sustainable water resource management of the Lake Bafa are presented in detail.