The latest large-scale researches of hydropower potential of large and medium size rivers in Russia were conducted in 1940–1980 years. Nowadays updating of hydropower potential data (including not only large, but also minor and medium rivers) is carried out. This paper is dedicated to the development and approbation of methodology and GIS-based tools for calculating hydropower potential of rivers, located in Russian Federation. The list of initial data and information sources used in research were described. The approaches and GIS-tools described in present paper allow executing an assessment of hydropower potential of the rivers in a short time on large areas.