Rainwater harvesting tips for beginners

How hard can it really be to collect rainwater? Just put down a bucket and wait for the clouds, right?

Not really. This task is deceptively complex, but it can be a game changer for some growers. Whether you have a small backyard garden or a large farm, making the most of rainwater—a free resource we all desperately need—is crucial. But before you jump into it, there are some important steps you need to take first.

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Check your local laws

Believe it or not, there are some states that have restrictions on rainwater collection. Colorado, Arkansas and Illinois All have restrictions on how residents can collect rainwater, how much they can keep, and what they can use it for.

Alternatively, some states, such as Florida, Rhode Island and Virginianot only encourage citizens to collect rainwater, but even offer incentives in the form of discounts or government rain barrels.

Use your collected rainwater to water your garden. Photo by DJ Taylor, Shutterstock.

In some cases, your state may not have laws mandating rainwater harvesting, but they may have specific plumbing codes that you must follow for complicated setups. If you belong to a homeowners association, you should also review your articles of association. Better safe than sorry.

What will you use the water for?

Before you collect a drop, think about what you will use the rain for. This will help you decide how big your tank should be, whether you need to deal with any extra plumbing, and where to store everything.

Rain barrels come in different sizes, and the size of your tank will depend on a few factors: how much rain you plan to collect and where you store it. It’s easy to forget when it’s a few drops, but water is heavy—more than eight pounds to the gallon. So when you have a 3,000-gallon tank, “it can be very heavy and dangerous at the same time,” says Christy Langendoen, owner of Water Storage Tanks, Inc. in Austin, Texas. She is also a board member for the American Rainwater Catchment Systems Association (ARCSA), a non-profit organization with great resources to help you get started. Because water is so heavy, as Langendoen explains, there might be rules or regulations that need to be followed when harvesting it in bulk. “You may need static for your tank so you don’t injure yourself and others,” she says.

Rainwater tanks for the home come in different sizes. Photo by zstock, Shutterstock.

By deciding what you’re going to use the water for, you can also figure out how you might need to treat or purify the water. Langendoen says that if you use the water to water your plants, for the most part you don’t need to treat it beforehand. But if you plan to drink or cook with the water, you should definitely do so. ARCSA has a procedure that will help you treat the water to get rid of sediment filtration and bacteria. “Rainwater itself doesn’t contain bacteria, but when it hits the collection surface, for example your roof, it picks up bacteria,” says Langendoen. Groundwater collection systems also exist, but once water hits the ground, it picks up bacteria along with oils and other sediments. So before you drink this water, purify it.

What is your maintenance plan?

Suppose you plan to only use the water to irrigate crops. That means you don’t have to worry about the treatment, right? Well, something like that. You don’t have to treat it the same way, but you do want to keep your water tank clean and dirt-free. This is where pre-filtration comes into play.

“We want to prevent leaves and dirt from getting into the tank. So there are different screens and different filters to keep these big debris out,” says Langendoen. There is also something called a first-flush transition, a device that automatically diverts returning inches of rainwater from your tank. “That assumes things like bird droppings and pollen are coming off your roof at that moment, which isn’t always the case. But there are different types of pre-filtration that you want to do for irrigation because you don’t want your tank itself to basically become a teapot with a teabag in it.”

A filter can help collect dirt and other things you don’t want in your rainwater. Photo by Glenn R. Specht-gr’s photo, Shutterstock.

Depending on how often you use your collected water, you should also make sure it is aerated to keep it fresh and to ensure it doesn’t become stagnant causing it to take on a cloudy appearance or develop algae or a surface Scum. The longer you use the water in between, the more important it becomes to aerate it. You can store the rainwater for a long time as long as you keep it pest free and aerated.

So should you collect rainwater? Absolutely.

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The benefits may be obvious to people in drier climates, but even residents of rainy states should take advantage of rainwater collection. “In your dry, arid states like Arizona, you want to catch the rain when it falls so you can take advantage of it when you don’t have it,” Langendoen says. But even in areas that can get a lot of rain, like the Pacific Northwest, collecting rainwater can help with stormwater management. “It holds back water during a rainstorm that usually flows straight into rivers and streams, causing flooding.” Holding back this stormwater can be very helpful in groundwater management and slowing the accumulation of water in low-lying areas.

It’s a bit more complicated than putting out a bucket and waiting for the clouds, but collecting rainwater is definitely worth it.

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