Ziway lake Basin is a large, heterogeneous, lithological unit that contains groundwater aquifersrnof domestic, agricultural, industry and environmental significance. Population growth hasrnresulted in expanding residential developments and consequently increased demand for water.rnIt is crucial that this resource has to be managed in a sustainable manner to safeguard it both forrncurrent users and for future generations. Eight aquifer systems having distinct groundwaterrnpotential and hydraulic properties. A shallow aquifer occurs in the lacustrine and alluvialrndeposits in the rift and highlands of weathered and fractured regions. Water levels in thernmodeled aquifers follow the topography and groundwater occurs under unconfined conditionsrnin the system.rnThe aquifer system was modeled numerically using Processing Modflow Pro (Version 8.0.15)rnunder a steady-state condition with one layer of 500 meters constant thickness. The model arearnwhich is about seven thousand four hundred fourteen square kilometer was divided into gridrnblocks of 250 by 250 meters. A number of data were collected from different sources for therndevelopment of this model. These data include: DEM, aquifer thickness, recharge,rnhydrogeological conditions of the study area, flow data, and pumping and observation wells.rnThese data were prepared and preprocessed using ArcGIS, surfer10 and Globalmapper11.Therncalibration of the groundwater model was performed using trial and error calibration. Therncalibration was implemented by changing several parameters such as recharge, hydraulicrnconductivity, and river conductance. The steady-state groundwater model was calibratedrnsuccessfully and the simulated heads were in a good agreement with the observed head. Therncalibrated model gave ME of -0.070613 m and RMS of 4.497221m.rnA sensitivity analysis was conducted to examine the response of the calibrated steady Staternmodel to changes in model parameters including horizontal hydraulic conductivity, recharge,rnand well withdrawal. The model was most sensitive to recharge and relatively less sensitive tornwell withdrawal. Three different scenarios were simulated to observe the response of aquifer byrnconsidering both increased and decreased 25%, 50% and 75% in the parameters (recharge,rnhydraulic conductivity and pumpage). The scenario and sensitivity analysis provided importantrninformation for future transient model development and on the data gaps. This model hasrnpertained for developing detailed predictive groundwater model, which can be readily used forrngroundwater management practices.