This paper presents a model for forecasting daily changes of water level in Lake Kinneret during flood periods. The model is based on the water budget equation. Its parameters are calibrated by multiple regression using inflow, outflow and rainfall for the preceding day. A correction factor which takes into account the errors of forecasts for the preceding two days is added to the model. Split-sample calibrations and applications yield results which are accurate to within 10 to 20 mm.