Collecting and saving rainwater for your garden is a smart practice. Our ancestors did this regularly. It’s easy to do, saves money on water bills, and conserves water.
Why Collect Rainwater?
Rainwater is often better for your plants than tap water. Tap water usually contains chemicals, salts, and minerals like chlorine, which can harm plants and soil. Rainwater, however, falls naturally soft. It contains fewer minerals like magnesium and calcium, making it ideal for plants.
Rainwater Collection Methods
The simplest way to collect rainwater is by using a downspout flowing into a barrel. You can set up a more complex system with pipes connected to a tank or cistern, which redistributes the water with a pump.
The most common method involves collecting rainwater from your roof. If you already have gutters and a downspout, you’re halfway there. Next, you’ll need a barrel. You can convert a new or contaminant-free 55-gallon drum into a rain barrel. Many garden centers also sell ready-made barrels with screens and covers to keep out debris, insects, and animals.
Install a spigot near the base of the barrel. If you can’t attach a garden hose to the spigot, raise the barrel enough so you can fit a watering can underneath. Make sure the stand can support the full weight of the barrel, as a gallon of water weighs about 8.3 pounds.
Need more water? You can connect multiple barrels using a pipe near the top. Once the first barrel fills, the overflow feeds into the next one. Many commercially-made barrels come with kits to link multiple units. If you have more than one downspout, you can pair each with a barrel.
Estimating Rainwater Collection
To estimate how much rainwater you can collect, multiply the square footage of your roof by the rainfall in inches. Then multiply the result by 0.62. For example, if your roof is 30 feet long and 10 feet wide (300 square feet), you can collect about 186 gallons of water from 1 inch of rain.
Cautions
Rainwater is great for the garden, but it’s not safe to drink. The Texas A&M AgriLife Extension provides detailed information on using rainwater beyond gardening, including how to treat it for other uses.
Always cover your rain barrels to keep out children, pets, and wildlife.
