The main objective of this study was evaluating the land cover changes on hydrological response in Gelda sub basin. The impacts of historical land cover changes witnessed between 1986 to 2017 on the hydrologic response (river flows and runoff volumes) of the Gelda watershed were investigated. The land cover changes were obtained through consistent classifications of selected Landsat satellite images. Their effects on runoff peak flows and volumes were subsequently assessed using selected hydrologic models for runoff generation and routing available within the HEC HMS. Physically based parameters of the models were estimated from the land cover change maps together with a digital elevation model and soil datasets of the basin using HEC_GeoHMS GIS extension tool. Observed daily continuous rain fall and flow data were selected from year 2008 to 2013. The simulated flows from the 4 sub watersheds were routed downstream to obtain the increased(changed) effects in the entire river basin. Model results clearly revealed significant and varying increases in the runoff peak flows and volumes within the basin. In the entire basin the flood peak discharges, mean daily annual flows and volumes increased by at least 0.55%, 4% and 3.32% respectively during the entire study period. The study successfully outlined the hydrological consequences of the land cover changes and hence the need for sustainable land use and catchment management strategies.