Installation of an automatic geothermal irrigation system for horses or cattle

This is a great way to automatically water your horses or cattle all year long. It depends on a small stream of water poured into a plastic tray. The idea is to keep the water moving so it doesn’t freeze.

Pipes that are exposed below the basin in the CMP (corrugated metal pipe), if prevented from being frozen by air being sucked through the water and draining the perforated field drainage pipe which is buried about 6 feet deep. Air is drawn into the drain pipe and returned under the sink through the water line casing pipe. I had my doubts about it but after two years I think it’s great. Being the plumbing business, I have a few things I plan to do on the next install.

The most difficult part is the excavation of the water line and the construction of a small drainage field for the overflow of the self-irrigating pond. Your existing water line is about 5 or 6 feet deep. You will need to dig to locate your existing water line and dig a trench to where you will install the water tank. This trench must be at least 50 feet long. The drain field line can also go in this trench.

The idea is to run a perforated line to the elevation of the water line, go down the trench 50 feet, and return to where you doubled the line to come up. This is where I modified the plans. I run a 4-inch schedule 40 pipe to the bottom of the trench, then install a 90 degree elbow and attach it to the perforated drain pipe that continues down the trench for 50 feet. Then turn around and carry the perforated pipe back to the CMP location.

Next, connect your new poly water line to the existing water line and run the pipe through the trench to the CMP location. Here I have installed a relief valve. This valve will drain the line to the sink if you shut off the main water line. If you ever have to shut down the line in the winter, it would be difficult to drain the line to the valve. This valve would shut off the water and drain the pipe so it wouldn’t freeze under the horse trough. Rain Bird Manufacturing will sell you this valve for about $3.00. The part number is 76A-FVP gold B40475 gold 16AFBDV. Any of them will work if you want to search for them on the internet.

After the valve is installed, you will need to drill a hole in the perforated pipe and insert the water line into the perforated pipe. I would put a 90 degree elbow here and run a solid 1 inch schedule 40 PVC pipe to the surface to connect to the valve in the basin. The water line goes inside the perforated pipe up to the height of the CMP (corrugated metal pipe) plus a little. This will bring heat from the soil along the side of the water line.

You should now have the water line and outer pipe leading to the surface. They will need to stick out about 1 foot above the surface of the soil. Perforated pipe should be visible only in the drain line. Now would be a good time to backfill the trench to the surface. Tamp down the soil while backfilling to provide a solid base for the water tank.

Next is the concrete base for the CMP. Manufacturing will require insulation under the concrete. I didn’t feel it was necessary since the rest of the slab is exposed to the cold. For the base I formed a rectangular shape out of some 2 x 4’s and bought some bags of concrete. The perforated pipe for the water line should be cut 8 inches above the gravel pad and the drain pipe should be cut 5 inches above the gravel pad. The difference between the elevations of the two pipes is what will create a draft to absorb heat from the ground and help prevent the pipes from freezing.

Place the CMP on 4 rocks that are placed at the correct elevation and level it with a carpenter’s level. There are some concrete anchors with the installation kit. Attach them to the CMP and get some bagged concrete. For concrete on the first rib of the CMP. You can smooth it out with a 2 x 4. There was some insulation with the install kit; I also bought a couple cans of insulating spray for the interior of the CMP.

The rest is easy. Assemble the valves and connect them to the tank. The drain line will be inserted into the casing. Connect the water line to the hose supplied with the kit and make the connection to the valve.

Valve adjustment is best described with the operating manual in the kit. One final tip for the operation of the automatic horse watering system, when you have the valve on, do not close it in the summer. This will save a lot of work in the fall.

Good luck, your horses will love it.