Implementation of new tasks for old dams: a non-trivial problem

In Central Europe many dams were built in the first years of the twentieth century. Now, 100 years later, many of the objectives valid in the design period are not relevant any more. Thus a decision has to be made, as to whether such a dam shall be removed or new functions be found. Such a decision requires a thorough analysis of potential new functions for the dam. In these cases the most important aspects are: dam safety, economy, scale of the water resources system, ecology and necessary technical modifications. Three examples are presented, in which such modifications had to be implemented. The individual systems and problems are discussed and methods for their solution are presented. It is demonstrated, that certain common features are obvious, although the projects are significantly different from each other. In all three cases continuation of the use of the reservoir was suggested. This became possible, however, only if the ownership of the dam changed.