Energy has been and will be the initiator of the movement of matter and of all the functions and activities of living beings on Earth. Hydropower is the most significant renewable energy source, which is economically competitive to produce electricity from fossil fuels and nuclear plants. Hydroelectric plants convert water energy into kinetic energy, then mechanically activate energy and then to generate electricity. Hydroelectric power in the broad sense means all buildings and plants used for the accumulation, supply and drainage of water, energy conversion, transformation and development of energy and regulation of the system. The concept of environmental protection include all activities and measures aimed at preserving the quality of the environment, rational use of natural resources, educating the public on environmental pollution problems and finding a solution to solve these problems. Narrow connection between building hidroelectric power plants and their environmental impact places and accent on thr necessity technological and legal aspect. By using less destructible technology, appropriate regulation, adequate monitoring of changes and increasing environmental protection should be longterm goal for all participants in hidropower exploatation.