Thanks for the suggestions, I have found a friend at church that is a certified Dive instructor with equipment, he specializes in Cave diving. He said that he is very comfortable in completely dark surrounding. So, Once I install a more permenant valve or plug on the back side of the dam, He will dive down to see if we can sleeve the the broken end and then grout the whole length of the pipe. Or leave it and double sleeve the lake side pipe with PVC? I'll keep ya posted on the progress.
I really appreciate any additional help you might have?