Water-conserving landscaping is no longer reserved for dusty yards in Southwestern states. As more developers and landscape architects foresee water shortages for even historically rain-rich regions, they're designing private lawns and common spaces with deep-rooted native plants that thrive with minimal watering. And they're investing in computer-regulated irrigation devices that deliver the precise amount of moisture needed to sustain each plant—and not a drop more.
“Certainly, there was a wake-up call [a couple of years ago] in the Southeast, which hadn't been used to dealing with water shortages,” says Alex Wilson, executive editor of Environmental Building News and founder/ president of BuildingGreen.
“In Houston, water availability isn't an issue,” says Michael Strong, vice president of Houston-based GreenHaus Builders. “Water's cheap here; we get a ton of rain. The big deal is that it's not going to be that way for long.”
Smart Growth. Water-conscious builders—and many green building programs—rank landscaping practices that minimize the need for outdoor watering at least as high as “smart” irrigation controllers, water-permeable paving products, and systems that capture rainwater or recycle graywater from a home's showers and sink drains. But a true water-conscious plan includes elements of each strategy.
“Limiting the need for irrigation should be the first concern,” says Matthew Nielsen, development manager for Windermere on the Lake, Connecticut's first planned community of LEED-rated luxury homes. The first item on a landscape designer's plan, then, should be drought-tolerant native plants, which thrive on whatever rain falls in a local area; using as little thirsty, shallow-rooted turf as the homeowner can tolerate is equally important.
“We encourage people to rethink what's beautiful,” explains Maureen Mahle, LEED for Homes program manager at Steven Winter Associates in Norwalk, Conn. “Homeowners are more open to [less turf and more native plants] than builders tend to recognize.”
Another tactic: small trenches around gardens and dips in the topography that cause rainwater to puddle around plants with roots that can tolerate it. “The key to conserving water in the landscaping is, No. 1, the way you create the lots, so you retain the natural rainfall as long as possible before it falls off,” says Tucson, Ariz., builder John Wesley Miller.
Go With the Flow. Following the creation of a smart layout and careful plant selection, products designed to further conserve and better manage water on the property also come into play. Creating a yard that requires little watering lets a homeowner get by using captured rainwater instead of potable water. Rainwater catchment systems—ranging from large vessels with attached garden hoses to underground cisterns that work in tandem with a sophisticated distribution system—harvest runoff from roofs and gutters.
Another technique is to distribute graywater—that is, water collected from household drains (not the toilet) that can be reused for irrigation—although it's one that builders and some jurisdictions aren't warming to quickly.
For the parts of the landscape that do need regular watering, water-conscious builders rely on drip irrigators that slowly wet only the plant that needs attention rather than spraying water over a whole lawn. Drip irrigators are rigged to timers to deliver a precise amount of water on a schedule that eliminates unnecessary watering. The newest irrigation systems are so “smart,” in fact, that they can sense whether and how much it has rained and will skip a scheduled watering if it's not needed. They are programmable to recognize the type of plant being irrigated and to deliver the specific amount of water each species needs, when it needs it.
Stopping Power. Just as important to a landscape design is controlling stormwater runoff, which can take with it excess chemicals and sediment.
A low-tech way to direct rainwater back into the soil instead of out onto the street and into storm drains is to hardscape with permeable materials. Unlike blacktop, these materials let water percolate down through joints between or through pores in their surfaces. Likewise, plantable pavers are designed with openings through which the landscaper can plant grass.
Regardless of method used, Miller says builders are in the best position to change the water-wasting habits of their home buyers. “We can have a major, positive influence,” he notes. “It's not too late to change.”—Sharon O'Malley is a freelance writer in College Park, Md. This article first appeared in EcoHome.
Resources Florida Water Star program:
www.sjrwmd.com/floridawaterstar
WaterSense (U.S. Environmental Protection Agency):
www.epa.gov/watersense/pp/new_homes.htm
Water – Use It Wisely:
WaterWiser (American Water Works Association):
www.awwa.org/Resources/content.cfm?ItemNumber=29269&navItemNumber=1561
