De la Fleur explained the difference between a typical conveyance system we use here in this country and the infiltration systems used in Germany. In the States, we concentrate on directing excess water off our properties, while in Europe, many systems keep water on-site so it can filter down into the ground. It was an on-site solution that de la Fleur proposed for the basement stairwell flooding.
Although Rush was skeptical and cost-conscious, he and de la Fleur agreed to team up to tackle the problem.
Project 1: Porous Pavers
The concrete patio at the back of the house directed water into the stairwell, so they began by tearing out that slab, along with the nearby crumbling concrete sidewalks. They would be replaced with porous pavement.
“In 2001, when I talked about porous pavement, people looked at me like I was a Martian,” says de la Fleur, who earned degrees from the Royal Botanic Gardens, Kew, and the University of Sheffield in England and now has his own business that focuses on sustainable solutions to landscape problems. Porous paving, also called permeable pavement, was almost unknown in the States when de la Fleur started the Elm Avenue project. These brick or concrete pavers have built-in openings or spacers between them so that rainwater drains through into the ground rather than running off.
De la Fleur did the job on the cheap by breaking up some of the old concrete and using it as a base. He topped the concrete with a layer of coarse aggregrate followed by smaller stone chips, then laid the pavers on top of that.
Voilà! The water problem was solved. When Rush saw how well the pavers absorbed the runoff, de la Fleur’s reasoning became clear: In our society, we pay to send water off our properties by building storm-sewer systems. We then pay to bring water in to irrigate our lawns and gardens. Why not just keep the water where it is? It was this savings of both water and money that impelled Rush to make the Elm Avenue property even more water wise.
De la Fleur was definitely on board with demonstrating how to keep water on-site. “I have a sense of urgency in trying to communicate what can be done in this regard,” he says. But people argued that his methods could not work in the United States. “I knew once I could show that it works in my back yard, then people would be more accepting of these new ideas,” de la Fleur says.
The next step was to capture the water that ran off the roof, by installing rain barrels. “Rain barrels and cisterns are very simple and ancient rainwater storage tools,” says de la Fleur. He recommended six—three on one corner of the house, three on another. They typically cost $75 to $350 each, too expensive for the budget. So Rush talked a local car wash into giving him used 55-gallon detergent barrels. He installed them himself using basic plumbing supplies. The rainwater captured in the barrels is used to irrigate plants.
Project 3: Rain Gardens
Native prairie landscapes are able to soak up almost all the precipitation that fall onto them, says de la Fleur. The prairie renews the deep roots of its plants every 3 years, contributing to the buildup of organic carbon in the soil. “It works like a sponge to soak up the rainfall and allow it to infiltrate into the soils,” he says.
So de la Fleur decided to install a prairie-inspired rain garden to absorb runoff from the garage roof and to replace the turf lawn next to the house. A rain garden is a shallow, excavated area, usually at a property’s low spot, with plantings that can tolerate wet feet. It is designed to absorb excess rainfall. To make his, de la Fleur manually removed the turf; loosened the top few inches of soil; and planted the area with seeds of native prairie plants, plugs he grew from seed, and sedges he rescued from a construction site.
Rain gardens can be daunting to people unfamiliar with the concept, so de la Fleur recommends starting small, with a 10-by-10-foot plot. “Experiment until you feel comfortable, then expand. If you make a mistake, it’s not hard to start over again,” he says.
Next came their most ambitious project yet: a green roof, a cover of vegetation over a water-impervious layer, laid on a building’s existing roof. A green roof absorbs water and helps to heat and cool a building more efficiently, but can be expensive to install. Rush told de la Fleur, “If you can find the money, let’s do it.” So the landscape architect applied for and received a grant from a local conservation organization, and they were off and running.
They chose to plant the front porch roof of the house, which was approximately 250 square feet with a pitch of about 15 degrees. De la Fleur’s wife, Catherine Haibach, and friend Ann Tranter installed a 1-inch lightweight aggregate drainage layer. Over that went 3 inches of growing medium, and into it were planted drought-tolerant plants. The system weighs about 25 pounds per square foot when wet. The total cost came to about $15 a square foot.
An established green roof requires little care, needing to be checked and weeded a few times each year. The growing medium and plants extend the roof’s life by protecting it from sunlight and temperature fluctuations. Before installing a green roof, however, a structural engineer should check that the roof can support the weight of wet growing medium and plants.
Projects 5 and 6: Cistern and Bioswale
At this point, Rush was so hooked on saving water that he wanted to aim for 100 percent retention of the water runoff on the property. An old underground masonry cistern, typical of homes built before the 1920s, sat unused on the north side of the house. Early residents of the house probably used the stored water for cleaning and laundry. The pair cleaned and repaired the old cistern to use the water for irrigation.
Next to the cistern on the north side of the house ran a strip of scraggly, seldom-used lawn. The men decided to replace it with a bioswale. Just like a rain garden—except for its shape, which is longer and narrower—a bioswale would capture any overflow from the cistern and allow it to percolate into the ground rather than flow into the street. Because this area was in the shade of the house, they used plants that prefer those conditions. The result turned an awkward, narrow space into another infiltration tool, one that bursts with color and texture from interesting native savanna and woodland plants such as perennial geraniums, ferns, asters, grasses, and sedges.
Project 7: Gravel Grass
The final project involved replacing a conventional compacted-gravel parking space next to the garage with gravel grass, another type of porous pavement that is little used in the United States. The base consists of gravel mixed with sandy soil (1 part sand to 5 parts soil), which provides good infiltration and is stable enough to bear the weight of a vehicle but does not compact so much that it cannot sustain plant growth. On it, de la Fleur planted a mixture of buffalograss, sideoats grama, fescue, and clover. Besides absorbing water, the advantage of gravel grass is that, when it is not being used, it looks like an extension of the yard because it is green.
Spreading the Word
By the time the men had finished their projects, they had spent about $2,500 in total. People in the community were starting to notice, and the two were asked to show the yard on a local garden tour. De la Fleur realized visitors would have many questions, so he organized the projects into seven stations with handouts explaining what each did and how they put it together. He also created a website, delafleur.com, that has these information sheets and explains every step of the projects and how to do them.
De la Fleur enjoys the teaching aspect: “It’s more persuasive to tangibly show people how they can make a difference.”
And Rush? Although he hasn’t calculated exactly how much money the Elm Avenue property has saved in water, lawn maintenance, and heating and cooling costs, he’s convinced enough to have since installed porous pavement at another of his rental properties and is looking to make the landscape around his own home more sustainable.
“Marcus is one of the extremely few people who wake up every morning thinking about what they can do for the planet,” Rush says. “I’m not that guy. I think I’m more like the typical American. I want to do the green thing but I favor a more practical approach. I want to be green and save money, as well.”
Lessons Learned from Elm Avenue
- We pay to send water away through our storm-sewer systems and then pay again to bring it back for household uses and watering our lawns.
- Areas of turfgrass absorb less runoff than a rain garden or bioswale.
- Rain gardens require less care than lawns because they don’t have to be watered, fertilized, or mowed.
- The enclosed front porch is now far more livable year-round because the green roof had the unexpected benefit of being a good temperature insulator, lowering heating and cooling bills.
- Going green can actually cost less. The water in the cistern and rain barrels replaced buying water for irrigation.
- One person can have an impact by reducing water usage and by demonstrating to others how it can be done.