GIMME SHELTER-Buckets of rain: Harvesting rainwater saves $

Garnett Mellen
Easement and Education Programs Coordinator, Thomas Jefferson Soil and Water Conservation District


Q: This spring, I finally got around to planting a garden, and I'm very pleased with my bounty. But I'm using an awful lot of water on all the new blooms. What is "rainwater harvesting" and how can it help me keep my garden growing?

A: Rainwater harvesting is simply the practice of collecting rain from your roof in rain barrels and using it, generally, for non-potable purposes like watering your yard or washing your car. The simplest, most effective systems consist of a barrel connected directly to the downspout of your gutter system, and with a spigot at the bottom from which to empty the barrel when it fills. Rainwater harvesting might seem cumbersome at first, because it does require regular maintenance, but once you learn the basics, you can conserve a significant amount of water and money with very little hassle. 

A typical rain barrel is 55 gallons, and will provide enough water for a one-inch watering of a small garden. And you could catch about 500 gallons of rainwater during a typical short summer downpour off a regular sized roof. So, you'll probably want to set up two or three barrels if you really plan to put a dent in your tap water usage.

Most large garden stores sell rain barrels for about $100, but local rain barrel makers will sell you one for half that price. To install the barrel, simply cut off the downspout of your gutter with a hacksaw, add an elbow joint to the gutter to bring it away from the wall, and place the barrel underneath. In order to create sufficient water pressure at the barrel's spigot, elevate it 15 inches or so off the ground, on a level pile of dirt or rock that can withstand the weight of a full barrel. 

It's very important to have a system in place that will direct water away from your foundation when the barrel overflows. (A barrel will fill in a few minutes during a typical short summer downpour, so you won't likely be around every time the barrel gets full.) Connect an overflow pipe or hose to the side of the barrel, near the top, and connect the end of that pipe to a regular drainage system, like the one that would be connected to the bottom of your gutter downspout.

Any stagnant water is a breeding ground for mosquitoes, so put a tight screen over the barrel's top if it doesn't already have a lid. You can also use a biochemical dunk for this purpose, or put certain types of fish in the barrel, but then you'll have to make sure there's always enough water for the fish. 

My first rain barrels were transparent, and I decided to let the kids turn one into an aquarium to keep the mosquitoes out since I hadn't put screens over them. Once the frogs and goldfish were in there, we got an algae problem, so I added snails. But eventually, the fish got really big, and some raccoons climbed in and ate the fish, frogs, and snails!

Another time, my kids were playing hide n' seek with a neighborhood boy, and we couldn't find him for the longest time. We finally discovered him inside our, thankfully empty, rain barrel. So, it's very important to use a firmly attached lid, especially if you have pets or young kids. Look for a barrel that comes with either a lid that can't be removed at all, or one that screws on tightly like a ball jar. Also, with a good lid or screening, you shouldn't ever have to clean the inside of the barrel. 



Anyone know a good local source for a polyethylene (plastic) storage tank? I'm looking for something to hold 500 gallons of non-potable rooftop runoff.

A reliable source says that both Southern States and Tractor Supply probably stock such tanks.