Groundwater modeling in integrated water resources use in the little Akaki Watershed, Ethiopia

Integrated use of surface and groundwater resources is essential to provide reliable water supply and to sustainably manage the water resources. In the Akaki watershed, groundwater pumping contributes for more than 25% of the water supply to Addis Ababa City, the capital of Ethiopia. The groundwater abstraction is significantly increased without reliable quantification of hydrologic and hydrogeological components of the water resources. In view of that, this study applied the SWAT model calibrated with SWAT-CUP for surface water simulation and MODFLOW model for groundwater simulations. The MODFLOW was calibrated using the water table and baseflow. Using the two models the surface water and groundwater potentials in the Little Akaki sub-basin under different recharge (change based on land use change) and pumping scenarios were analyzed. The combination of the two models, SWAT and MODFLOW models successfully estimated the surface water and groundwater resources and the results found were acceptable.