Pond Boss Forums POND CONSTRUCTION Building a dam Overflow Pipe or Not

Pinetar, if you haven't read the threads that I list below, you should. There's a lot more than just sticking a pipe thru the dam and letting it stick up in the pond:

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=253695

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=272310

I'd double check with the NRCS office to make sure the pipe is sized correctly. I wouldn't want to think about having to pull it out and installing a larger one. They'll have the information to size it correctly, and to give you the correct freeboard dimension. There should be 2 measurements that are critical in building a dam. I think they are Primiary Overflow pipe to emergency spillway and emergency spillway to top of dam. There's a formula for the depth and width of the emergency spillway too, so it's sized correctly. You don't want water going over the top of the dam during a 100 year rain event.