Rain Collection Systems 101

Harvest rainwater right from the rooftop with a collection system that reduces municipal water usage in the yard - and even indoors.
By: Gretchen Roberts

Water: Finite, increasingly expensive and a must for every household, this precious commodity can be captured from the sky, reducing dependence on municipal water, saving money and conserving one of Mother Nature's most precious resources. Rain collection systems can be as simple as a rain barrel that collects water from the gutter or as complex as a 7,000-gallon underground tank that filters and pipes rainwater into a home or business for indoor use.

A rainwater collection system is appealing in this age of environmental awareness and personal economy, says Bob Drew, founder of EcoVie Environmental, a rainwater collection systems company in Atlanta. The primary environmental advantage: Rainwater is stored in a tank for later use instead of running off and causing erosion, flooding and pollution problems from overflowing city sewer systems. For the property owner, there is a net-cost savings, and water quality is higher, Bob says. Since an American family of four can use 400 gallons of water per day, the savings potential is high, especially in areas with plenty of rain and high municipal water costs.

A basic rainwater collection system consists of a holding tank, above or below ground, which collects rainwater from the roof via gutters and downspouts. The tank's filter weeds out large debris like sticks and leaves, and a pump directs collected water toward its intended use — often outdoor irrigation, but sometimes indoors for flushing toilets, doing laundry and even drinking water, which requires extra filtration.

The initial cost and long-term savings potential of a rainwater collection system depend on several variables, including the size of the storage tank, the level of treatments, how much water can be collected and the price of water in your area, Bob says.

"For example, a 3,000-square-foot rooftop with a 1,000-gallon tank might cost $10-15,000, or a few thousand more if you pipe the water indoors," Bob says. "But the payback period is short — sometimes just 5 to 10 years, depending on your water rates and how much you use." As to the system's longevity? Most tanks are warrantied for 50 years, with pumps lasting five to 10 years. "There is some maintenance needed eventually, but overall, systems are fairly maintenance-free," Bob says.

For a typical residential system installation, Bob looks at average water usage, the goals of the customer (cost savings, erosion runoff, etc.) and historical rainfall data to determine how the system might perform. Installations take two or three days, or up to five for more complex ones. Some landscape designers or engineering firms install systems, but often specialty companies do independent or subcontracted installations.

Home and business owners opt to install systems for a variety of reasons. "Most have a desire to be green, to altruistically do their part for the environment. Others want to go off the grid and become self-sufficient with their own water supply. Some people are trying to solve runoff and erosion problems on their property," Bob says.

Learn more about rainwater collection systems at www.harvesth2o.com, the online rainwater harvesting community, or find an ARCSA (American Rainwater Catchment Systems Association) accredited professional at www.arcsa.org.

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