The purpose of this study is to determine the hydrological properties, groundwater potential, and water quality of the Çürüksu basin, western Turkey, and to contribute to the efforts of providing an adequate water supply for the city of Denizli. To achieve these objectives, the study consisted of mapping the geology and hydrogeology, determining the water balance, and defining the water quality.
The basement rock units in the study area include several impervious metamorphic rock types and Mesozoic karstic limestone, which are overlain by Oligocene fluvial and lacustrine strata, Pliocene travertine and limestone, and Quaternary alluvium. The karstic limestone and the travertine and limestone strata constitute potential aquifers in the Çürüksu basin.
The discharge regimes of the 22 springs in the two basins show little change through the year. The flow systems of the springs also have a large storage capacity and drainage occurs very slowly. The discharge of the springs does not appear to be affected immediately by monthly variations in precipitation.
According to the water balance, the precipitation in the Çürüksu basin cannot provide all of the measured surface runoff. Excess runoff is 2 m3 s–1 in the Çürüksu basin, and in the adjacent Gökpınar basin the deficit in surface runoff is also 2 m3 s–1. Thus, the underground catchment area of the springs extends beyond the surface drainage area of the Çürüksu basin. Although the Pınarbaşı, Kazanpınar, and Böceli springs emerge from the karstic limestone aquifer in the Çürüksu basin, these springs are fed from the adjacent Gökpınar basin.
The spring waters emerging from karstic limestone are fresh, of the calcium bicarbonate type, soft, and potable. The spring waters emerging from the travertine and limestone aquifer are low-temperature, brackish, of the calcium sulfate type, very hard, and not potable but useful for the irrigation. The occurrences of coal strata and hydrothermal activity have caused some deterioration of groundwater quality.