An accurate design and application of support systems for underground structures and its performance evaluation have become increasingly critical to both the safety and the economics of the construction process. Lack of appropriate and efficient measures could significantly affect the physical and mechanical properties of rocks. It is necessary to thoroughly observe the results of field investigations, such as geological structures to determine the type of rock, and groundwater conditions along the planned tunnel route. This study presents observations on the rock characteristics which determine the type and requirement of rock support for the intake tunnel of Meninting Dam. Rock mass has been classified by Rock Mass Rating (RMR) system. The result shows that no mixed quality of rock conditions is encountered at the excavated rock face. The RMR values of 24 and 29 fall into the rock mass Class IV category indicating the local geological structures of intake tunnel are poor rock. Rock supports in the form of rockbolt, shotcrete and steelribs are provided to reinforce the structure. Rockbolts of similar length and spacing together with shotcrete of 100 mm thick with wiremesh are applied to refine and strengthen the exposed rock surface whilst steelribs of the same material and spacing are provided to complete the reinforcement mechanism along the intake tunnel.