STORAGE CAPACITY: Ashton Woods Homes' Enclave at Riverwalk community in Atlanta will draw from an irrigation system supported by three 2,500-gallon cisterns that will store rainwater captured from the neighborhood.

Photos: Sears Smith & Associates

STORAGE CAPACITY: Ashton Woods Homes' Enclave at Riverwalk community in Atlanta will draw from an irrigation system supported by three 2,500-gallon cisterns that will store rainwater captured from the neighborhood.

Atlanta has been getting plenty of rain lately. But memories of last year’s drought conditions haven’t faded and have led builders and developers to incorporate water-saving designs into their communities that, in some cases, include rainwater catchment.

Next month, Ashton Woods Homes is scheduled to open models for Enclave at Riverwalk, a five-acre community of 32 townhomes, 20 of which will contribute to a sustainable landscaping system that collects rainwater in large cisterns for irrigating lawns and drought-resistant plants. This is the first time Ashton Woods has added rainwater catchment to one of its subdivisions, and Ralph Farrell, its senior vice president of operations, tells BUILDER that his company—which for several years has built its homes to Environments for Living guidelines—is looking to install similar systems in future communities.

Georgia is one of several states in the Southeast that have become more concerned about whether or not water availability can keep up with current demand and future growth. In March 2009, Georgia’s Environmental Protection Division imposed restrictions on water use in response to the state’s severe drought. “That’s when we said to ourselves ‘let’s get into the rain harvesting business,’ ” recalls Chris Sears, a principal with Sears Smith & Associates, an Atlanta-based landscape architect that designed the catchment system Ashton Woods is using.

That system, which is adding about $1,500 to the cost of each unit at Ashton Woods’ community, works this way: Water from the back roofs of the houses runs through downspouts into a leaf collector and then through drains into a 6-inch collector pipe that runs underground into three 2,500-gallon cisterns. Those tanks are equipped with pumps that return the water to an irrigation system that, according to Sears, “is part drip, part spray, with minimal motors.” (He explains that while the elevations of certain houses at Enclave prevent them from contributing rainwater to this recycling process, all of the homes in this neighborhood will draw from the cisterns, which will also provide water for the common lawn area.)

Sears estimates that a 1-inch rain event over 15,000 square feet of roof area equals 7,500 gallons, which would be enough to run an irrigation two or three times, or more than enough to supplement the 3 to 4 inches of rain that Atlanta typically gets in a month.

The system met with approval from several constituencies, including officials from Cobb County and the National Park Service, the latter of which oversees the nearby Chattahoochee River. But Sears’ company had to wait to promote what it was doing until Ashton Woods finished selling the last 10 homes in the first phase of its Riverwalk subdivision, which does not include rainwater collection and storage.

Rainwater catchment can be found with greater frequency at commercial projects in Georgia, but “is still very new” to residential development there, says Sears; so new, in fact, that the state’s plumbing code had to be amended to accommodate the systems being installed.

A few other Atlanta-area developers have embraced this method of water conservation and recycling. Green Street Properties is using a stormwater pond to irrigate its mixed-use Glenwood Park community in Atlanta, which at build-out will include 375 residences, 20,000 square feet of office space, and 48,000 square feet of retail space. Another project currently in its design phase, called Waynesboro Senior Homes, will capture rainwater for irrigation. Steve Munier, president of Bridgeland Development, which with Hammond Development is working on this project, says this is his company’s first community to include underground rainwater retention. The two-acre project, which will have a total of 39 rental units, is being financed in part by Affordable Housing and Historic Preservation tax credits.

Both Glenwood Park and Waynesboro Senior Homes are being built to green standards set by Southface Energy Institute’s EarthCraft Communities. Next month, EarthCraft will update its criterion for water conservation that will require the amount of outdoor potable water used for irrigation to be 50% below baseline conditions. Consequently, developers that install rainwater catchment systems might have an easier time earning points for achieving that goal, says Christina Corley, EarthCraft Communities’ project manager. “I do not see the water conservation issue going away just because the region has seen more rain,” she stated in an e-mail to BUILDER. “Developers are still trying to capture rainwater and stormwater, and are working hard at translating this effort to potential buyers and renters who will have to pay the bill when water rates increase.”

Farrell of Ashton Woods says that, despite higher upfront costs, rainwater catchment is a “win-win” for homeowners who will ultimately pay lower utility bills and homeowner association fees.

John Caulfield is a senior editor for BUILDER magazine.

Learn more about markets featured in this article: Atlanta, GA.