Predictions of the impacts of climate change on the intensity, amount, and spatial and temporalrnvariability of rainfall and temperature are required. The aim of this study was to assess the status ofrnclimate change and hydrological response to climate change for Gumara River sub-basin. ThernHadCM3A2a and HadCM3B2a (Hadley centre Climate model 3), output of Global Circulation Modelrn(GCM), scenarios of climate change were used for predicting the future climates of the study area.rnStatistical Downscaling Model (SDSM 4.2) was used to downscale large scale predictors into finer scalernresolution. To estimate the level of impact of climate change, climate change scenarios of precipitationrnand temperature were divided into four time windows of 25 years each from 2001- 2099. The Soil andrnWater Assessment Tool (SWAT) was used to simulate the hydrological response. SWAT was firstrncalibrated and validated using observed data and the SDSM downscaled climate outputs were used as anrninput into the SWAT model to assess the hydrological responses of Gumara River due to climate change.rnThe period from 1986-2000 were taken as a base period against which a comparison was made. Thernresults showed that the SWAT calibration and validation reveals a good agreement with R2=0.9 duringrncalibration and R2=0.89 during validation whereas NSE= 0.89 during calibration and 0.86 duringrnvalidation. The monthly and seasonal downscaled precipitation, maximum and minimum temperature inrnthe future time horizons did not show systematic increase and decrease i.e. increases in some months andrnseason and decreases in some other months and seasons. Annually, both precipitation and temperaturernshowed increasing trends in all future time horizons (Precipitation increases up to 13.7% whilerntemperature increases up to a maximum of 1.01oc). Based on monthly, seasonal and annual changes ofrnprecipitation, maximum and minimum temperature, the SWAT model was rerun for each time horizonsrnand the results reveal, as that of precipitation and temperature, the monthly flow volume did not showrnsystematic trends i.e. increases from month of April-September up to a maximum of 134.54% for A2a andrn127.52% for B2a and decreases in the remaining months by 47.44% (A2a) and 46.62% (B2a). Seasonalrnand annual flow volume increases in all future time horizons as compared to the base period. Seasonally,rnthe maximum increment was shown in the major parts of the rainy season (Kiremit) and small rainyrnseason (Belg) in which the flow volume increases by 144.65% for A2a scenario and 101.58% for B2arnscenario. Moreover, the annual increment showed systematic trends and the increment reaches up torn17.65% for both scenarios at the end of 21st century. Thus, the hydrology of Gumara River is highlyrnvulnerable to climate change especially in the rainy seasons which causes high floods and therefore,rnconsidering climate change impacts is advantageous in any water related issues on Gumara sub-basin.rnKey words: Blue Nile, Gumara River, Climate Change, SDSM, Hydrological Modeling, SWAT ModelrnLake Tana Basin, Ethiopia