Pond Boss Forums POND CONSTRUCTION Building a dam Question about overflow pipe size

I'll throw another variable in here having lived your situation for the last 10 years - also in West IL - it's not worth the stress.

I've got a decent size pond (6-7acres) with a similar watershed to the one you describe. Every time we get spring rains or a big water event I basically stop sleeping. My emergency overflow is about 20 ft wide and during big rain events it'll run 3 feet deep.

I'm adding a larger culvert and also a siphon drain so I can lower the pond level in anticipation for a big rain - but if I had it to do over again I'd rethink the pond location.