I have a pond that is a little less than an acre. When I built it (it is 1 year old) my conservation people told me I only needed a 4 inch drain. The guy who was building it laughed and said nothing under 10 inches. The conservation guy kind of said whatever you think but that is overkill for this particular location. Needless to say beingkinda green I took the four inch pipe like an idiot. My pond now overflows over the damn evertime it sprinkles because I have a large run off. 2 questions is this just a freak of a year with all the rain or should I spend the money an put in a 10 inch culvert? 2nd It is just a drain that runs over the damn and down but guess what problem I am having? You guesses it crawdads and leaking under the pipe because of them. Does anyone know of a good way to stop them? I have tried concrete and I have dug it up 2 times trying to get it right and am about to try a third. I thought I would ask for advice this time with some people who have expierence with this. my kid and I have a ball with it feeding fish catching fish but with the problem the drain is giving me I am considereing pulling the plug. I followed the hatchery and everyones advice when stocking it it. It is really doing great except for the overflow pipe. Oh I have nothing but red clay and I am located in ohio on the west Virginia border in case anyone was wondering.