How to Harvest Rainwater From Your Barn

Save money on your water bill without sacrificing water quality.

Rainwater, when collected properly, is even safe enough to be used as potable water. (Credit: AQHA Calendar)

The average American Quarter Horse drinks five to 10 gallons of water daily, with this number rising as exercise and temperatures increase. Add in baths and hosing down injured legs and your water bill can result in some heart palpitations.

The good news is you can significantly cut down your water bill by installing a rainwater harvest system on your barn. Rainwater collected before it hits the ground can exceed the quality of ground or surface water. Capturing it rather than letting it flow across your property will also minimize erosion and flooding!

To turn your barn into a water source, you must first take a look at what the roof is composed of. The best roofing material for capturing rainwater is uncoated stainless steel or galvanized steel with baked-enamel. It is important to ensure the roof’s coating does not contain heavy metals, such as lead. While shingle roofs can be used, they are more likely to support mold, algae and bacteria growth, as well as significantly cut down on your collection efficiency. Shingled roofs tend to hold back some water that would otherwise have made its way into your system.

The easiest way to create a rainwater harvesting system is through a rain barrel. These can be purchased ready-made, or you can do it yourself! Rain barrels should have a tight fitting lid and screens on the downspouts to prevent them from becoming a breeding ground for mosquitoes and other disease carrying insects.

When selecting a barrel, lean toward barrels made out of an opaque material such as metal, wood or a dark-colored plastic. This will restrict sunlight from entering the barrel which will in turn inhibit algae and bacteria growth.

What You’ll Need

  • Power drill with a 4- and a half-inch hole saw

  • Barrel with lid

  • Bung and tap

  • 4-inch to 3-inch PVC adapter

  • Screen grate

  • Hose clamp (large enough to fit over the 4-inch side of the PVC adaptor)

  • Non-toxic caulk

Step By Step

  • Using the 4-inch hole saw, cut a hole in the lid of the barrel.

  • Using the half-inch hole saw, cut a hole in the side of the barrel 2.5 inches from the bottom of the barrel.

  • Insert the bung in the barrel and make sure there are rubber washers to ensure a watertight seal.

  • Connect the tap to the bung.

  • Cut a section of screen grate measuring about 6 by 6 inches and place it around the large opening of the PVC adaptor.

  • Use the ring clamp to hold the screen in place and remove any excess screen around the edges.

  • Place the PVC adaptor into the hole on the lid and caulk around it to create a watertight seal.

After completing these steps, your barrel is ready to be installed. It is a good idea to build up a level base out of cinder blocks for your barrel to sit on. Place the barrel under a section of your barn where water runs off. If you have gutters installed, you can simply manipulate your gutter to dump directly into your barrel.

It is simple to make and use a rain barrel, but if you want to completely rely on rainwater to meet your water needs, you will need to either make multiple rain barrels or invest in a cistern. To calculate the size of system you will need based on average rainfall and desired output, take a look at Texas A&M AgriLife Extension’s Rainwater Harvesting Supply Calculator.

Capturing rainwater is a great way to offset a little cost without sacrificing any quality. Before you begin to build your rainwater harvesting system, you should check your state laws and calculate just how much rain can be captured, based on your annual rainfall.

Happy money savings!