Installing a Tinkler tube or overflow pipe in your pond requires the pond to drained or be at a minimum water level.
Heavy equipment such as a backhoe is required although it may be possible to excavate for it by hand.
The diameter size of the tube depends upon how large the pond is and how fast a rate water enters the pond.
A Tinkler tube is often used when occasional water flows over run the spillway and provide an emergency escape for the excess water.
This helps prevent excessive overflow at the spillway from underscoring the spillway base or washing away by erosion, the embankments surrounding the spillway itself.
One of the easiest materials to construct a tube from today is HDPE piping.
It is typically used as under drain pipe at driveway entrances or between catch basins in parking lots and so on.
It is typically black in color and has ribs on the outside.
Easy to cut and easy to handle due to it being light weight, this type pipe makes the job much easier.
You will need one twenty foot length of pipe, one ninety degree elbow and a PVC or HDPE baffle that slips over the pipe.
Tell your supplier what you are doing and they will know what to give you.
The minimum size pipe for a small pond would be twelve inches in diameter.
Larger ponds may require an eighteen, twenty-four or even larger diameter pipe.
You will also need a tripod, builders level, a rod and an extra hand to help set elevations on the pipe as it is installed.
These tools can be rented by the day at most good rental centers.
If you have never used them before, ask the store owner how to use it and they are always glad to give a quick lesson.
Locate your tube close to the spillway but not right against the sides of it.
Allow a few feet of soil to remain between the spillway sides and the new tube.
Once located, have your excavator dig a trench through the dam face as deep as the bottom of the adjacent spillway from the waterway at the bottom of the spillway into the pond about five or six feet.
The bottom of the trench may be level as water will seek its own level and will flow easily out of the pond and into the downstream waterway.
You must assemble the tube so the elbow sits at the bottom of the intended location of the vertical location of the pipe riser.
Once you locate the elbow install the baffle over the horizontal portion of the tube that will go from the elbow to the exit end.
Baffles are about twelve inches wider than the pipe on all four sides and are installed to prevent pond water from seeping alongside the pipe and causing a leak.
Place some material over the pipe to just hold it in place while you install the riser section.
Using your builders level, determine the elevation of the top of the spillway boards at high water level.
(The point where water spills over.
) You must install a riser pipe that is about one inch higher than the elevation of the spillway boards.
The intent is to allow the Tinkler tube to allow heavy water flows to spill downward into the pipe and exit the pond without going over the spillway or side embankments.
High water flows from rapidly melting snow or heavy rainfalls actually pile up behind a spillway's boards.
This force of nature allows the Tinkler tube to function and when the water flow slows, the spillway resumes it's normal flow and the tube goes dry.
With the pipe fully assembled, back fill the pipe in layers or lifts using the same soil you removed from the pond bottom, carefully removing any large stones that could pierce the pipe.
If the existing soil is too wet to re-use you may import new soil but it must have a high clay content to allow complete packing when compacted.
No sandy soils may be used.
The use of a compactor to firmly tamp the back fill material into place is highly recommended.
This assures there are no air spaces or pockets left behind that water can infiltrate and cause a leak alongside the new pipe.
If you doing the installation during growing season, place some rye grass seed mixed with some better quality seed, perhaps Kentucky blue grass and the like.
A covering of hay will help hold the new soils in place and keep moisture from evaporating during hot days.
Getting a good grass cover on the exposed parts of the embankments as well as the pond bottom will help prevent any erosion when the pond refills itself.
Pete Your Friendly Building Inspector