This project has been devised to get a larger series of hydrology data through a dendrochronological approach and utilize it for hydropower evaluation of the Swat River catchment. For the purpose of dendrochronological analysis, Tree-ring samples were collected using increment borers and measured by Velmax measuring system. The previous hydrological data ranging from 23 to 55 years of the same tributaries were collected from Water and Power Development Authority, Pakistan and Pakhtunkhwa Energy Development Organization (PEDO). Both dendrochronological and obtained hydrological data have been applied to reconstruct the long-term hydrological data of more than 200 years. The reconstructed hydrological data has been used for hydel power potential estimation of all studied tributaries. The current investigation presented the same pattern of flow rate and power potential in existing and reconstructed hydrological data with minor variances. The findings of this research demonstrate that reconstructed hydrological data can be obtained by using existing hydrological and dendrochronological data, and it can act as the best source to measure the expected flow rate and hydropower potential.