I have for sale an Agra Drain brand water level control structure. You can change the level of your pond or let water into a second pond as you like. You control the level by raising and lowering the gates inside. I used it to fill a duck marsh until we changed a few things! It is the 6” pipe model that is 4’ tall. It was over $700 new; I’ll take $200 for it with some pipe included!
I live west of Brookville