Not sure if it helps but I have continuous flow coming out of my trout pond, albeit it's at a much smaller flow apparently than your pond. I'm moving almost 60,000 gallons a day into and out of the pond which is about 45 gpm. I use regular drainage pipe with at least one collar close the pond and another farther away to keep water from working under the pipe and eventually the entire length of the pipe, which it will if you don't use a collar.
I used to be a believer in an emergency overflow type of overflow lined with stone (ditch at the top of the dike),and fed into a culvert pipe in the next pond in the series, but I'm rethinking that. Problem was I've had star faced moles digging holes in the sides of the emergency overflow and down 2 to 4 feet into the dike. And they were digging under the pipe the water flows into at the end of the emergency overflow. If I would not have caught this it was just a matter of time before I had some serious problems.
One more thing I've learned from the school of hard knocks: Don't under size your drainage pipe. It's always better to go bigger than smaller.
Last edited by Cecil Baird1; 08/29/09 01:18 PM.
