[en] The aim of this study was to estimate local and regional average annual run off in the surroundings of Svartboberget located close to the middle of Sweden roughly 100 km west of the Baltic. It was also meant to give an idea of reliability of given run off figures and possible improvement using a more sophisticated approach including direct measurements of precipitation discharge and deeper analysis of discharge records. The study was based on economical, topographical and geological maps as well as areal photographs. Run off was estimated to be 9.9 l/s km² locally with a proposed certainty within +- 0.5 l/s km². This certainty may be improved to half that figure with proposed measurements during a period of 10 years.(author)