Increasing attention is paid to problems concerning water resources planning. It is essential that the hydrological information required is available to the planner in a form that facilitates combination with other types of information.

This paper describes the development of a system for calculation and presentation of regional and comprehensive hydrological information. Main components of the system are the interpolation routines, a water balance model adapted to the space and time scale and a data base for supporting information. Examples of presentations are given.