Diversified underground waters of Krakow – an asset or a problem

Abstract

Geology of Krakow is much complicated because of the fault tectonics that has formed horsts and troughs of various sizes, composed of Jurassic limestones and Cretaceous marls. Due to such a geological structure two hydrodynamic zones, the upper and the lower one, can be distinguished within the city area. The quality of underground waters of the both zones cannot be compared straightforward. If the quality of the lower zone waters is satisfactory overall, the same pertains only to water-bearing horizons of the upper one, i.e. those that have formed under natural conditions and can be today considered potable. The quality of other upper water horizons is very much inferior to them and results from centuries of various human activities producing, e.g. domestic, urban or handicraft effluents and sewage that have contaminated and degraded more shallow-water horizons. In contrast to them, some waters of the deeper hydrodynamic zone are even of the mineral type and occur under artesian conditions. They are currently used in the Swoszowice spa in therapeutic bathing and for drinking and also in the re-opened drinking facility close to the Mateczny roundabout. There are also some places across the city, where such underground waters have been made usable to the public. Concluding, depending on the quality of waters and on the site from which they have been rendered available, the underground waters of Krakow may represent either an asset or a problem for the city inhabitants.