A simple soil moisture simulation model to use in irrigation water management issues was developed. The model employs traditional water budgeting approach, and includes mechanisms for simulating soil moisture movement, root growth and crop evapotranspiration. The model requires only a few readily available input parameters. This model was evaluated through a case study conducted at a farm in the Goulburn Irrigation Area in Victoria (Australia). The soil moisture simulation results demonstrated the effectiveness of model and revealed that the developed model was quite successful to account for the variability of evaporative demand of tested perennial pasture and the amount of rainfall received during the irrigation period. The qualitative and quantitative procedures used in model's evaluation supported its use to deal with agricultural water management issues for yielding significant water savings.