Global warming affects the fundamental variations of the hydrological regime and water resources. According to the climate change scenarios, the increase of air temperature as well as changes of precipitation and total evaporation might influence the annual distribution of river runoff and cause changes of the extreme runoff elements. These prognosticated changes may affect the development of water ecosystems by the new environmental conditions. The use of renewable energy sources in Lithuania as well as in EU countries is very important. One of the most usable sources of renewable energy is...