Hydroelectric plants are highly dependent on predictable runoff patterns. In the case of Nepal, the specific runoff maps are not available yet and the most of the gauge stations are at low level land. So there is the great challenge of getting reliable hydrological data at intake sites, most of which are at high mountains. The catchment of Nupche and Likhu Intake is far from the gauge station having snow covering and with topographical variations. So, to estimate the flow at Nupche and Likhu intake of proposed Nupche Likhu Hydropower Project Rainfall-Runoff (HBV) Model used. The validated HBV Rainfall-Runoff Model used to estimate the flow of Nupche and Likhu intake of proposed Nupche Likhu Hydropower Project. Only the catchment characteristics of these intake was used as the input of the validate Model. The monthly estimated flow data by the HBV Rainfall-Runoff Model has found similar (Within 10% Variation) with valid monthly flow data. The HBV Rainfall-Runoff Model found applicable to estimate the flow at Nupche and Likhu Intake adjusting catchment variation with the reference of rainfall data of nearest gauged station. The Model can use to estimate the flow of other ungauged catchment after calibration and validation with nearest gauge station

Keywords : Hydropower, Ungauged Catchment, Flow Estimation, Nupche and Likhu Khola, Nepal.