The new intake of Wanta Expansion Hydro Power Project is located in Wushe Reservoir in central Taiwan. It mainly includes a 48 degree inclined shaft (penstock tunnel) with 110 m length. Because the main structures of the inclined shaft are constructed in expected poor geology with high groundwater pressure, high construction risk will be encountered. In the paper, the design considerations and construction measures of the inclined shaft are studied. It may be helpful to the construction of similar projects in the future.