Due to ageing of dam seepage flow in a concrete/masonry dam occurs through the material, through joints and the cracks developed due to any cause.
Best possible way to arrest seepage is to treat the upstream face to prevent ingress of water, saving complete cross section of dam.
Because of wet and dry conditions the revetment on upstream side was disturbed in almost all dams. Undulation cavity, unequal settlement, heavy growth of bushes and trees found on the upstream side rip-rap area of the dams.
These defects have a severe effect on more seepage of water in the gallery. Because of leaching effect, many drainage holes are blocked and new seepage occurs adjacent to the existing drainage holes.
The solution to these defects are, the reaming of the blocked holes to remove the lime deposition, leveling the old jetty stone base with Leveling in Stones or with gravel and repacking the area with new and old removed stones in order to have a uniform surface, and treat the Masonry Structures.