During the construction of our home in 2001, we hoped to find water for our well at a shallow depth. Unfortunately that wasn’t the case. Our well is a staggering 660 feet deep and refreshes at a paltry 4 gallons per minute.
Rather than rely on that water source for gardening and animal needs, I installed a system on our barn to catch rainwater. The barn is 25’x40’ which means the roof has a surface are of 1000 square feet. For every inch of rainfall that hits that roof, approximately 600 gallons of water can be captured.
Details: How the System Works
The key to the catchment system is the storage tanks. I have two 1500 gallon tanks, each placed on an 8’x8’ concrete pad that is 6” thick. These tanks were purchased from Tractor Supply for approximately $500 each.
To capture the rainwater, gutters span the entire length of each side of the barn. I attached large diameter PVC sewer pipe to the downspout. At the bottom of this pipe is a cleanout that can be used to remove leaves and other debris (usually once each winter). Connected to the modified sewer pipe is a smaller diameter PVC tube which carries the water to the top of each tank.
I installed a small solar panel on the barn which powers a DC pump to move water to where it is needed. From the tanks, I trenched about 300 linear feet out to the middle of the garden and installed small diameter PVC pipe at a depth of 3 feet.
In total, counting the cost of the tanks, solar, pump, renting a trencher, and pipes, I have invested about $1700 into this water catchment system.
The rainwater catchment system has been in place for about 6 years. Each year we harvest about 30,000 gallons of water (based on 48 inches of average rainfall). This allows me to keep the cows and chickens watered as well as provides a bit of extra water for irrigation. Probably the only thing I would do differently would be to use a 120 volt AC powered pump. The cost of the solar panel, pump and battery is hard to justify.