Type of aquifers and location of public waterworks of Germany
About 40 % of Germany's land area is covered by porous aquifers, some of which are very productive. A large proportion of the public waterworks that use groundwater are located here. Reservoirs for drinking water supply, on the other hand, are mostly located in hard rock areas with insignificant groundwater resources, especially in Saxony, Thuringia and North Rhine-Westphalia
Source: BGR