The equivalent to the Polish Dębowiec Formation are coarse detritic sediments of lower Badenian in the territory of the Czech Republic. They fill deep depressions in the roof of Carboniferous formation, and considering the conditions of coal exploitation, form the most important hydrostructure. Statistical analysis of groundwater analyses allowed to ascertain hydrochemical environments marked: I and II-IV. In the environment I (the Bludovice depression) waters of the type HCO3-Na are the most common. The II-IV environment is represented exclusively by stagnant waters of the Cl-Na type. The most remarkable change of the waters type is observed in the narrow, central zone of the Bludovice depression. For groundwaters in depressions of the second order (connected to the Bludovice and Detmarovice depressions - of first order) two variability models of ions concentrations were formulated. The highest I concentrations are typical for waters in the Darkov deprssion (of the second order), and for the Region of Darkov.