Try Your Hand at Harvesting Rainwater

Sarah Moore Impact Mill Contributor

Water use in the United States is pretty exorbitant. The average family uses about 320 gallons per day, 30% of which is funneled outdoors to the garden and lawn.

Sadly, the vast majority of that water comes from aquifers and groundwater, which are replenished slowly. While the rate of groundwater recharge follows complex mathematical models, it’s an uncontested fact that aquifers will not refill at the rate at which we’re draining them. That’s when the real crisis begins: exacerbated drought, water scarcity that affects both individuals and agricultural, and civil unrest following the conflicts that these shortages will precipitate.

Wherever possible, therefore, it’s crucial that we use less water and get it from sources other than groundwater. You can start by harvesting rainwater, which makes use of a free natural resource most of us ignore – rain – while reducing runoff and lightening the load on the municipal water supply.

Rainwater Harvesting Basics

At its most basic level, harvesting rainwater is pretty darn easy: put barrel under the gutter downspout, wait for rain, use the water that ends up in the barrel to irrigate your lawn and garden. Boom. Water-wise move accomplished.

Of course, it’s a touch more complicated than that, but not much more. Doing a little math can help you calculate both how much rainwater you can expect to collect based on roof size (though how much rain your area gets also matters, of course), and how much you’ll need based on what you want to water. Then you can plan your rain barrel system accordingly.

Overcoming Your Objections

Rain barrels

Rainwater harvesting isn’t as daunting as you might think | image: Jennifer C./Flickr

Lots of people look at setups for harvesting rainwater and think…well, that looks freaking hard and messy. But actually, the problems commonly associated with rain barrels are not as big as you might think. For instance, take barrel overflow. Sure, your rain barrel(s) will overflow if you never use the water, and this will create soggy patches that might be bad for your home’s foundation (though no worse than a gutter downspout simply emptying onto the ground).

With diverter kits, it’s easy to address this issue by connecting several rain barrels to a single downspout, or routing water from one barrel to another. If you’re really ambitious, you can channel water straight to the garden, or back up to the roof to create a green roof.

If mosquitoes are a concern, you can treat your collected water with eco-friendly dish soap or vegetable oil, or use bacteria-based mosquito dunks for serious infestations. Additionally, you can set up a simple screen system so mosquitos can’t access your barrel in the first place.

Algae problems, on the other hand, can mostly be avoided simply by putting a light-proof lid on your rain barrel. Like any other plant, algae needs sunlight to grow, so this is a pretty painless solution. Algae and mosquitos can also be avoided by using your collected rainwater relatively quickly.

Maintain Your Systems

Once you’ve got your rain harvesting system in place, you’ll need to keep it in good shape. This requires periodic maintenance, but no more than you’d likely do for gutters anyway. The main chores are cleaning gutters and downspouts to avoid buildup of leaves and other debris. You may also need to use roof wash, which helps keep your roof free of mold, fungus, and other growth so that your water stays clean. Choose an eco-friendly option so you create water that’s safe for your garden, the ground, and you!

Rain barrels are not a perfect answer to the water scarcity problem, nor are they install-and-forget systems, but they are a fantastic and relatively easy way to make use of a rarely harvested natural resource. Try it…you might be surprised how easy it really is.

Sarah Moore is an Impact Mill contributor and freelance writer who focuses on sustainability, local food, and the weirder side of science. In her spare time she enjoys writing fiction, running, and cooking. Sarah lives in Portland, Oregon, with her husband, two children, two dogs, and an unshakable colony of June bugs.