Pond Boss Forums POND CONSTRUCTION Building a dam Outlet Reconfiguration

fozzy:

I use a plastic grid fence (the stuff Stoney Creek Equipment sells, looks kinda like black snow fnce, often used to make fish cages) set out about 18" into the pond from the inlet to my over flow. I have the fence tied to five steel "T" fence posts, two driven into the bank on either side of the drain, three into the pond bottom in front of it, with insulated copper electric wire remnants. The fence forms a semicircular screen in front of the drain.

Under low and medium overflow conditions, the water runs through the screen (without any larger fish) and into the drain. I have the highest, uphill edges of the fence set so that if the water level should rise that high, water will by-pass the fence on the back side. I do not think the water level has gotten this high except for one time right after installation. (The drain pipe is double-walled plastic, corrugated on the outside and smooth on the inside, with a thin collar on the uphill ends to slide the next piece of pipe into. I originally left the collar on the top piece of pipe, and it collapsed during a heavy flow restricting the drain. I cut the collar off this top piece and it solved the problem.) If the water gets high enough to by-pass the fence, I'm willing to lose some fish in order to help save the dam.

Although the fence is frequently clogged with FA and/or floating weeds at the waterline, the below surface portion usually seems to be clear of obstruction. The portion of the fence that is above the normal waterline is always free of clogs when the water rises and goes through it. I haven't ever cleaned it; as water rises it reaches a clean part to flow through.

I must say your design is a lot more visually appealing. I think you will have to place your cobble in cement to keep it from washing away in a heavy flow.