River inflow works as fuel for hydroelectric plants (HEPs) and it drive the energy output from HEPs. This study is carried out to predict changes in Balui river inflow due to potential climate changes. A hydrological model was developed to simulate river inflows at Bakun HEP. Model was calibrated using observed river inflows and then further used for long term river flow generation for future period of 2011-2070 by projected CanESM2 future rainfall. It is noted, under CanESM2 RCPs, low flow (Q95) at Bakun HEP would increase by 35 to 42, median flow (Q50) would increase by 6 to 10 and high flow (Q5) would decrease by 9 to 11. From Q30 to Q100, the inflow to the Bakun Dam would significantly improve especially under RCP 8.5, which would result improvement in Bakun HEP future reservoir operation. © 2016 Taylor & Francis Group, London.