Jackie Koerner

Rainy Review of Rain Barrels

Painted Rain Barrels from Milwaukee Metropolitan Sewer District's Website

I’ve always tried to be green about things, especially when it comes to water conservation. I intend on getting two rain barrels for the house once I get my hubby to agree. The rain water collected in the barrels should not be consumed. It is best suited for watering gardens, grass and trees. Some people even use the water to wash their cars, house and even the dog. Using rain water instead of throwing it away down storm drains helps the community and keeps lawns free of muddy grass paths created by rainwater runoff.

A bit more about rain barrels: Lawn and garden care account for 40% of the water consumption during the summer months. This is about 1,300 gallons! Using rain barrels also decreases the runoff into storm sewers and bodies of water. One inch of rain on a 1,000 square foot roof equates to 623 gallons of runoff. Talk about a waste of perfectly good water…

Although not necessary, it’s kind of cool to see how much water you might actually be saving by using a rain barrel – at least us science geeks think it’s cool. To calculate the area of your roof, simply use the Pythagorean Theorem to find the length of the roof. This is easiest if you have a simple peaked roof, but you can go about finding the surface area of your roof by just examining each A of each section of roof. Measure the length of the house, the width, the height of the house from ground to gutter and the height of the house from ground to roof peak. From these measurements, take the width, divide by two – this will be your “run” as shown above or your “a” in Pythagorean Theorem. Then take the height (measured from the ground to the peak of the A) and subtract the height from the ground to the gutters. The result will be your “rise” or your “b” in Pythagorean Theorem – now plug into Pythagorean Theorem to get your “slope”. And finally, take your resulting “slope” and multiply by the length of the house. Don’t forget to multiply by two as this is just for one half of the roof. Voila – the area of your roof. Now, you can multiply your roof size, by the number of inches of rain your town gets per year. Now, multiply by .623 and you will get the number of gallons you could save each year! I think to make this less confusing, I’ll vodcast myself doing this for my own house.

Rain barrels range from free to over $100. I saw a pretty nice looking plastic lined wooden one at Sam’s Club for $100 a few weeks ago. You can also build your own rain barrel with instructions from the Maryland Environmental Design Program’s website. Some municipalities sell rain barrels at a discount to assist with the reduction of rain water runoff. Some western communities, however, do not allow for rain barrels due to the water shortage during summer months.

In St. Louis, Metropolitan Sewer District recently started charging a monthly service fee to residents for rain water run off. They even are charging it to residents without public water or sewer. They take the impervious surface (i.e. rooftops, decks, patios, driveways) area and multiply by a factor to get the monthly fee. The only way to get out of it is if 80% or more of your property borders a body of water. Not many St. Louisians live on peninsulas. I’m not thinking that the use of rain barrels would eliminate the fee, but they began charge a fee due to the issue of overflowing rain sewers. This creates a larger issue than just wet shoes and mucky sidewalks. This ultimately can contaminate drinking water reservoirs.

One of my “tree hugger” friends posted to his blog, exclaiming that rain barrels are bunk. Above I have listed some wonderful uses for the water collected from the roof tops of homes. Josh first said the water was not good to water veggie gardens.  I don’t know of many people who water their veggie gardens with Evian. Besides, fertilizers, which plants love, are made of calcium, manure and decaying biomatter that could possibly make it into the rain barrel from the roof. In response to the “mosquito population” factor, there are actually mosquito dunks designed for use in rain barrels made of bacteria that feed on mosquito larva. One could also use chlorine or bromine, but that might be harmful if use on plants, especially if one does not carefully monitor the ratio.

For more reading, see this great little rain barrel publication.