Question

Cement Dam   QUESTION: My question is in respect to a medium sized pond that recently got a cement wall (dam) placed along one of its sides. It is now leaking.  in attempt to avoid 500 kilos of cement I want to use clay to fix the leak, I have little experience of this such, what advise can you offer me, thank you for your time and offering your skills.

...aManda Greene

ANSWER: The pond should be drained to just below where the leak has occurred.  The clay would need to be packed into the cracks or hole and allowed to harden.  If possible I would use expanding foam on the outside of the cement wall and the clay on the water side of the wall.  This will ensure that all of the little crooks are filled.  If you need additional information let me know... dave

---------- FOLLOW-UP ----------

QUESTION: Thanks Dave!

You gave me some ideas but, I wasn't very clear in my question.  Rather then a medium pond it is a small dam.  I have attached a picture from the original repair.  On the other side of the Cement wall is earth, and therefore not reachable for patching.  I would think to just put in a bell shaped mound on the bottom on the wall where the leaks are, compact it, let it dry and pray for the best.  Am I close?  What are some things I need to consider?

Thanks again for your answer and for your time...aManda  

Answer
The biggest consideration is water pressure.  If you have a dam that is damaged then you should consider how much force is behind the dam and will the structure continue to withstand that much force.  The other option to using clay is to use a quick set cement. Either method would require the area to be dry.  You description of applying the clay is good.  Keep me posted.. dave