In the paper the results of estimation of real and model-based surface runoff in the Chumysh river basin depending on a certain calculation scheme for winter precipitation sum (maximum snow cover water equivalent) are presented. Numeric experiments showed that the most suitable method for estimation of maximum snow cover water equivalent for low hills is calculation schemes for winter precipitation sum depending on orographic component to vertical movement velocity or depending on approaching to orographic barrier. Traditional schemes applied to calculation of maximum snow cover water equivalent by the use of the interpolation method based on the observation data and depending on true altitude produce less accurate results.