Hydroelectric power stations exert a great influence on distribution of the electric power on regional and, especially in the wholesale electrical power markets in models of the type "water resources – electricity consumption". In this article outlines some principles of creation a technique of calculations for hydroelectric power stations. We will call model of such type of R-P-L (resources, production, load) of hydroelectric power station. Considering uncertainty of a drain of hydroelectric power station and information difficulties, tasks traditionally is divided into two parts, depending on the planning period - the long-term and short-term modes. In the scheme of use of the R-P-L model there are a lot of features and changes in comparison with the last developments executed for Unified Energy System.

Keywords: hydropower resources, development, optimization, efficiency, energy balance, forecasting.