Groundwater flow modelling is important to calculate the quantity and quality of groundwater for better protection and management. The modelled aquifer is extensively used for irrigation, municipal, and domestic water supplies and this study documents the development and calibration of a numerical model to simulate the groundwater flow. The model is also used to show interaction between groundwater and surface water. A three-dimensional groundwater flow model, with one unconfined layer, was used to simulate groundwater flow in the Lake Awassa Basin. A sensitivity analysis to changes in model...