We are in desperate need of a second opinion on our dam. We have a 3 1/2 acre pond which average is 20-25 ft deep that is now 2 years old. We suspect that there is a leak in the drainage pipe underneath the dam. With in 3 weeks of completion we had a freekish storm that filled this pond up completely within 16 hours and was actually pouring out the spillway. We really didnt expect it to hold, and neither did the contractor, the dam just didnt have time to settle at all. But it did and it has up till now given us no trouble. The problem that we suspect is that there is a hole in the drain pipe under the dam. When we got the massive rain, we think that the water pressure in the pipe forced water through the hole and has eaten away at the dirt around that hole. As the water drained out of the pipe it drew the dirt back through the hole and deposited dirt outside pipe on the other side of the dam. We know this because of the color of the dirt is the same as the dirt that was used to construct the dam. Over the past 2 years we have had 1 or 2 of these massive rain storms. All this summer our pond has been down about 3-4 feet. About a month ago we had Hurricane Jean come through and dump alot of rain that filled the pond up level again. Then 3 or 4 days later we disovered a large sunken in crater about 4 ft diameter right below water level above the drainage pipe. Evadently, the water pressure from above caused this cave in. There is a constant stream of air bubbles comming up from this crater. We have had many clues to lead us to this conclusion, but at this point its still speculation. We have contacted the contractor and have not had much progress. We would like another contractor to come and give us a second opinion, but I cannot seem to locate one that would be suitable. In the mean time, the crater is continuing to enlarge, and dirt at water line 5-8 feet on either side of the crater is cracking and dropping rather fast. Every day we see more deterioration. We are very concerned that this dam is going to give way before we can get anyone out to look at it.
Any suggestions would be appreciated.
