The mortar used for pointing has worn out, and cracks have developed in the masonry joints due to which there was lot of seepage in the drainage gallery. As per recommendations of Dam Safety Review Panel, treatment of the block joints was carried out. The treatment consisted of chipping out the worn out mortar from the joint and then grouting the joint with a hydrophilic flexible PU grout, which seal the joints and also allows  any movement in the block joints.