I know I have not been here in a while, but I need some SERIOUS Help here.
As you may or may not know, I built about a 9.5 acre lake about 2 and a half year ago. Ok also, I have had a BUNCH of trouble getting it to fill up to the top with water. The lake is abouyt 30 feet deep in the deepest part. Recently, about 4 months back I deverted anothe stream to this pond to try to help fill it up. There has been water flowing in it for about a month now and this is very littel change in the water height.

Today I did a little bit more investigation and I have notice about 50 or so feet behind the dam in the original creek channel there is a good stream of water through there. I have come to the STRONG conclusion that I have a major LEAK!!! There is no way that there should be that amount of water flowing through there!! I am CERTAIN this is the reason why the lake will not fill up.

Now I have spent 3 years on this thing along with alot of time and effort to get my lake done.
What do I do about this leak? How do I go about fixing it?
If I have to drain the lake, thats no big deal at all. Should I try to fix this from the front or the back? Like I said draining it and loosing the fish is NOTHING at this point. If draining it at this point fixes my problem I will be glad to do it.
I was with the contractor two years ago when he cut the core and it seemed to me that he went deep enough. But for some reason the lake is not holding water. In fact it has NEVER filled to the top.

PLEASE HELP!!!! \:\(