The enormous importance of water for human settlement is reflected in the huge quantity of Slavic lexemes in mediaeval settlement names, referring to different kinds of bodies of water, marshland, distinct features of water and so on. Yet place names can also indicate the use of water, as will be shown for Bohemia in thes essay. In analysing these names, the essential precepts of onomastics must be observed. Firstly, rather than giving a run-of-the-mill account, names reflect a distinguishing feature particular to a certain settlement. For example, the name Mlynec indicates that a mill was the only one in its vicinity (and therefore outstanding enough to feature in the name of this settlement(. Secondly, many places names which may appear to refer to the use of water might also have other origins, such as metaphorical relations. In order to determine the impact and the use of water in early mediaeval settlement areas, it must be concluded that there are more reliable ways than counting corresponding topnyms. Analysing the complete toponomasticon of a settlement region offers a more precise picture, as is demonstrated for the region eas of the lower River Neisse/Nysa Lužycka at the end of this essay., Christian Zschieschang., and Obsahuje seznam literatury