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

Need some opinions from the experts... In the process of building basically a new dam / pond... Dam is nearly finished, contractor wants to put in a 18" overflow pipe in addition to the spillway. Is this absolutely necessary? The only really good location for the overflow pipe is about 30 feet from the spill way and the backside of the dam is kinda steep there which will be an erosion issue and I really just don't really want the pipe. Is it a bad thing to have water trickling over the overflow on a continual basis?? Then when we have a substantial rain having a large amount of water flow over the spillway??