Pond Boss Forums POND CONSTRUCTION Building a dam Question on the overflow

Typically, the emergency overflow is for flood conditions, the overflow pipe is used for all other rain events.

For some reason last night the screw cap part didn't register in my brain, so I was thinking of corregated steel drainage pipe. Of course, plastic won't rust.

Bob is 100% correct about the freezing part, even with an open end, pipe could freeze and break.

Yeah, pop for the valve. I know it hurts, but when you consider the cost of the valve in relationship to the cost of the whole pond project, it really isn't that much. Shop around, don't skimp on quality. You really don't want to replace it a couple of years in the future. If the valve and any associated piping will be exposed to the sun, make sure you get plastic pipe that has UV inhibitors in it, or the pipe will get brittle and crack. It may take 3-5 years, but it will.