Abstract
The Katowice conurbation is situated in the Upper-Silesian Coal Basin, in a region which had high rate of water inflow in the pre-mining period. In order to make deposits of mineral resources accessible, it was, and still is, necessary provide mines with a draining system, which now reaches as deep as 1200 m. The area of the depression sink which was thus created is about 1200 km2. Currently, all metal ore mines within the conurbation, as well as part of coal mines, have been closed down, but water which flows into them is still pumped out due to the legal obligation to protect neighbouring operating mines. After the operation and drainage of mines cease, water coming to abandoned excavations will begin restoring static reserves in the orogen, which, depending on hydrological conditions, will take between several and a few dozen years. As the level of underground water rises, the process of subsidence of old shallow mining excavations will intensify, and many depressions may appear in highly urbanized areas. In areas of mining subsidence, the underground water-table will be close to the surface, causing flooding of basements and building foundations, and the deepest subsidence basins will probably be completely flooded. Current location of operating mines on the northern and southern sides of the conurbation with the central belt of drained excavations is unfavourable for its sustainable development. A solution, which would make it possible for the conurbation to grow, would be to close down and flood the mines on the northern side as soon as their mining concessions expire, which will be in early 2020s. Then, the area would regain its original stability within a decade and all kinds of construction activities could be carried out there. That, however, requires authorities of municipalities to object to the extension of concessions for mines, which may be impossible to obtain due to fears of social discontent resulting from miners - residents of those municipalities - being made redundant.