Pity the poor yard. It receives constant care and attention during the spring and summer, but let a few dry spells or heavy downpours mar its beauty and efficiency and suddenly it’s the bad guy.
Sustainable design is the hottest trend for residential landscapes, according to a recent survey by the American Society of Landscape Architects. The results revealed that members expect the greatest consumer demand for residential outdoor-design elements that are environmentally sustainable, reduce water costs and require little maintenance.
Harvesting rainwater and greywater took the top spot in the survey of landscape projects expected to have the highest demand in 2016. Also popular are native and drought-tolerant plants, permeable paving, rain gardens, low-maintenance landscapes and water-efficient irrigation.
Laura Allen, author of "The Water-Wise Home" and co-founder of Greywater Action, a collaborative that leads workshops and presentations on greywater — water coming from sinks, showers and washing machines — believes that many conventional landscapes prevent water from being used as a liquid asset.
“Most yards are designed without consideration for the climate and natural rainfall patterns,” she said. “People often shape their landscapes to remove rainwater from the property, and then they have to water more.”
She advocates designing a landscape to capture the rainwater so it will soak into the ground and deeply charge the soil with moisture.
You can start small and make incremental changes to the landscape. Consider consulting with a landscape-design professional who specializes in sustainable practices to get an idea of the scope of the work. Also, check local codes to ensure compliance with building and landscape ordinances.
“People can choose the easiest projects for their landscape,” Allen said. “They can put in a simple rainwater-catchment system that will collect free water the first time it rains. If they build a greywater system using their washing machine water, they can build it in one or two days. And then every time they do laundry, they will be irrigating a portion of their landscape.”
If you are building a new home, addition, patio or driveway, try to minimize hard surfaces that can’t absorb water by installing pervious concrete or pavers, which allow rainwater to seep into the ground.
“Many people have a fully paved driveway, and they may only need strips of concrete for the tires to drive on or a parking space,” Allen said. “Also, there are nonpermeable options like gravel. Interlocking pavers have openings in the middle. Plants can grow in them, and rain can soak in them. Someone designing a new landscape can design the landscape to soak up as much rainwater as possible.”
Choose native plants that coexist rather than compete with the environment. Once established, the vegetation requires little water beyond normal rainfall.
“People can have plants that sustain themselves just from the rainwater,” said Allen, who lives in Los Angeles. “Native plants are great to grow, but people have more options. They can choose plants from other regions of the world that have similar rainfall patterns. In California, we can grow plants from similar climate regions like South Africa and Australia.”
At Sterling Custom Homes in Austin, Customer Selection Manager Christine Mann said home buyers have the option to choose drought-resistant plants. The builder’s website lists several plants that thrive in the Texas Hill Country, including Jerusalem Sage, a bright-yellow hardy plant native to the Mediterranean region.
“The landscaper reviews the design, what customers are looking for, and they will discuss what they want to put in the flower beds,” Mann said. “If they say, ‘I don’t want to water much,’ the landscaper will go for more drought-resistant plants.”
Many civic landscapes showcase demonstration sites that are designed to encourage responsible landscaping.
If you visit the Smithsonian’s National Zoo, find inspiration for a water-wise landscape at the Speedwell Foundation Conservation Carousel. Near the menagerie of colorful hand-carved animals is a rain garden strategically placed to intercept stormwater runoff and hold it until it can be fully absorbed into the ground.
It’s one example of how the zoo, a conservation organization, demonstrates good stewardship at the 163-acre park through sustainable practices, said Jennifer Daniels, the zoo’s senior landscape architect.
“The Smithsonian has an LEED [Leadership in Energy and Environmental Design] Gold directive for our large projects,” she said. “Animals have a relationship with the land. We are obligated to do the right thing.”
The rain garden adds to the educational and sustainable components of the solar-powered carousel exhibit. The objective is to take pressure off the District’s storm sewers.
“If one home puts in a rain garden, it’s a critical first step to encourage the entire community to work together on ways to contribute to the healthy function of the watershed,” Daniels said.
At the Science Museum of Virginia in Richmond, stormwater-management technologies are used in an initiative that serves as a model for low-impact development. The Rainkeepers program aims to encourage behaviors that reduce the flow of stormwater and pollutants into the city’s stormwater-sewer system.
Museum scientist Eugene Maurakis pointed out some of the facility’s eco-friendly features, including a garden filled with native plants, tree-well filter boxes, a rain garden, a pervious concrete parking area, and a rainwater harvesting, storage and irrigation system. A roof covered with vegetation was installed to minimize the amount of hard surfaces and to reduce heating and cooling costs. Indoors, the museum features 22 exhibits that highlight the ecological benefits of these practices.
To fully appreciate sustainable landscaping, consider the animosity that can grow between neighbors over runoff that damages property. Such disputes can get ugly and frustrating unless homeowners work together to minimize the problem.
Effective stormwater management is the goal of an ongoing collaboration between Jennifer Horn, a landscape architect in the Washington area, and her clients in the Bannockburn neighborhood of Bethesda.
Horn has been working with Juliette Searight and her husband, David Evans, on their landscape for about four years. Last summer, as the couple’s Cape Cod was renovated, a dumpster was parked a few feet uphill of their home. During a torrential downpour, debris blocked the flow of water between the dumpster and the street. Taking the path of least resistance, the water traveled through a neighboring yard and down a slope to Searight and Evans’s home. About 3 inches of water flooded their patio, covering it with mud.
Their neighbors, Cheryl and James Dodwell, hired Horn to help them manage the water’s flow after that incident.
“We’ve lived here for 16 years, and these water issues have become worse over time,” said Cheryl Dodwell. “We’re noticing the impact of these big storms and deluges more lately. I feel terrible when some of our mulch ends up in our neighbors’ back yard.”
Horn created a dry riverbed along the shared property line, fortified with boulders and rain-garden plants to capture and divert water. She’s still fine-tuning the project.
“The construction began in November, and it is, no doubt, a work in progress,” Horn said. “But I think it illustrates a growing dynamic among neighbors — how to respectfully and carefully manage the flow of water as it moves from your property onto your neighbor’s with as little impact as possible. The water has to go somewhere, so how we do collaborate with neighbors to manage it?”
Several factors make the Evans-Searight property vulnerable to flooding. Their street runs downhill from a cross street, and the drainage patterns and design of the curbs are insufficient for the length of the street, according to Searight.
“We’ve had water moving this way before, but never with this force or volume,” she said. “We have very low curbs, and water just careens over the curb sometimes. It’s not a regular occurrence, but when it happens, it’s a big nuisance.”
It’s also a challenge because, Searight said, there are no gutters or stormwater drains on her street. “Our street not only collects stormwater from our block, but it also collects stormwater from the block above us,” she said. “As soon as there is a dumpster or car on the street, all the debris that comes in the water — leaves, branches — this volume of water sweeps debris, which makes a little dam and goes over the curb and into our back yard.”
The Dodwells also turned to the Montgomery County Division of Highway Services for help in mitigating the flood risks. Curb replacement on their street is planned for this month. Barring funding problems, the entire neighborhood is expected to undergo street improvements over the next two years, including spot patching and resurfacing.
“The county has been so responsive and great in terms of working with us,” said Cheryl Dodwell, who described the overall experience as an “interesting collaborative process.”
“It’s been pleasant, but I could imagine a scenario where it couldn’t be,” she said. “It can be a pretty tough issue. Stormwater is really a force of nature, and managing it can be such a challenge. I feel lucky that we live next to friends, and we have been able to take this positive approach together.”
Cheryl Dodwell says Horn’s help has been invaluable because she is able to see the situation from both sides and design a solution that takes everyone’s needs into account.
The threat of future flooding on her neighbors’ property has Dodwell keeping her fingers crossed.
“We are just trying to do what we can do to be prepared,” she said. “The next big storm will test us.”