I think rain barrels are one of the best irrigation systems ever.

Water falls from the sky seasonally every year, and collecting and storing this precious resource for the sunny days ahead is brilliant. Not that this a modern idea by any means. What people have been collecting for centuries just happens to be coming back into vogue. Did you know that a mere 1 inch of rainfall can yield 600 gallons of water from a 1,000-square-foot roof? That’s a tall glass of water.

For those of you that aren’t entirely clear about my rant (and rave): A rain barrel is a large container (might be an actual barrel; might not be) that’s connected to the end of the downspout that descends from the ends of your gutters.

As the rain washes off the roof, instead of going through the downspout and becoming storm water run-off, it’s collected into a barrel. There’s usually a screen over any open areas to keep out debris, as well as to prevent mosquitoes from setting up home and reproducing.

Most rain barrels have a spigot at the bottom for easy filling from a watering can or bucket. They’re simply a win-win for any gardener, but they can be invaluable for those growing in the drier states such as California. Straight rainwater isn’t limited to the outdoors either. It can also be used to wash clothes, flush toilets, and wash cars.

Like everything else in life, there’s some controversy going on around rainwater collection. Some people refer to it as “natural soft water” because chlorine, fluoride, minerals, and other chemicals haven’t been added by humans. Still others claim there are impurities in rainwater due to chemicals leaching off of the roof itself as potential contamination from air pollution.

Another, perhaps even more interesting, fact is that it might just be illegal. That’s right. Apparently there are those who believe the water falling over your home doesn’t belong to you, and therefore it can be against the law to harvest it. So before you get all free-water-happy, be sure to check that it’s legal in your state.