Grouting is frequently used in underground projects such as tunnels and dam foundations to cover porous rock fractures and reduce groundwater seepage through the rock mass. After grout is injected into the rock mass, it is anticipated that the rock mass hydraulic conductivity will decrease as the grout solidifies. Rock anisotropy factors affect the rock mass quality; permeability, strength, and dynamic rock qualities are caused primarily by discontinuities at each location point, either laterally or vertically. In an embankment dam such as Meninting Dam, the part of the main dam foundation that carries the most significant amount of stress and anticipates subsurface flow or seepage needs to be repaired to strengthen the rock mass and lower its permeability value. Considering these factors, grouting trials are essential. These studies are primarily designed to test and assess the effectiveness of the suggested grouting injection pressures, distances, and patterns. A trial grouting was conducted on the foundation of Meninting Dam, which revealed an average Lugeon value of 1.69. As a result, the Lugeon value decreased semi-logarithmically, getting closer to the Technical Specifications’ aim of less than Lu 3.