Hydro-power and its ecological implications

Hydro-power is not only one of the oldest energy sources of man but played also a significant role for his cultural development. During the Antique Age water-puma, watermills and other water driven engines and instruments such as the water-organ and water clocks reached a high level of sophistication. Along with the fast expansion of watermills ecological impacts started during the Middle Ages, when the construction of millstreams and even the damming of lakes became significant activities. The critical change from local towards regional environmental impact, however, started only in connection with hydroelectric power engineering and comprises mainly the period since 1940. Its ecological, socioeconomic and even seismic consequences are underlined and described in this paper: It will be, however, demonstrated that the most unexpected positive ecological outcome from certain constructions of hydroelectric power-plants did also occur. (author)