Installing the Pipe and Round Fence
Cutting holes in the pipe
The pipe is prepared by cutting holes to allow trapped air to escape and the pipe to sink. These holes need to be large enough so that air is not trapped by surface tension across the hole. Since the upstream end of the pipe will be protected by a filter or round fence and the downstream end is protected by the receiver fence, there should be no concerns about the beavers detecting water movements through these holes. In a double walled polyethylene pipe, holes should be cut on the top and the bottom to allow the pipe to completely fill with water. In some cases it may be necessary to anchor the pipe in the middle to keep it from floating.
Rolling up fencing for the round fence.
Bending the prongs to close the round fence.
Creating a top and bottom for the round fence.
Cut a length of fence in half lengthwise to create a piece approximately 20 feet X 3.5 feet. Cut the crosswise wires at one end to create prongs. Roll up each end to start the bend in the fencing material. Wrap the two ends together and bend the prongs to secure the ends together to create a circle. Lay another section of fencing on top and trim to fit the circular shape and to create prongs. Bend the prongs around the sides of the fence to secure the top. Turn the round fence over and repeat to create a secure bottom. In very shallow water where the round fence would extend at least 2 feet above the high water mark, it may not be necessary to add a secure top, however, the top and bottom add strength to the structure as well as securing the pipe opening from beavers.
Insert the pipe into the round fence filter.
Drill a hole on either side of the pipe. Insert the pipe into a hole cut into the side of the round fence. Thread a ¼ inch steel rod through the fence grid and through the holes in the sides of the pipe to secure it to the fencing. This steel rod will prevent the pipe from twisting or pulling out of the round fence. The pipe may be secured in a similar fashion to the fencing on the receiver fence. The downstream end of the pipe at Peterson Pond is not attached to the receiver fence.
Moving the pipe and round fence out into position.
Moving the pipe into place by the receiver fence.
Dropping the round fence into place while securing the pipe in place at the receiver fence.
Since Peterson Pond dropped off to around 8 to 10 feet in depth shortly past the end of the receiver fence, a small boat was needed to move the round fence into place. The round fence and pipe was loaded onto the boat. As the boat moved out into position the downstream end was guided over the receiver fence and into the hole in the receiver fence that was cut prior to installing the end of the fence. The pipe was held in place while the pipe and the round fence were dropped into place. The round fence was simply dropped off the boat into the water. The holes that were predrilled into the pipe allowed trapped air to escape and the pipe and fence sank to the bottom. In this situation where there aren't any significant currents and the fencing provided significant weight, it was determined that no additional measures were needed to secure the round fence in place.
Next Page: The Completed Beaver Deceiver