Everyone benefits when stormwater sinks where it falls
Rain gardens sound exotic, but they are really a low-tech way to help rain soak in where it falls, replenishing water supplies and reducing pollution in waterways.
Roof gardens, on the other hand, have the same goals, but are something you should not try at home without the help of experts.
Marcus de la fleur has installed both - along with other tools - on a 50-by-150-foot lot at his home at 168 Elm Ave., Elmhurst. De la fleur is a landscape architect who wants to show homeowners how and why they can prevent stormwater runoff.
"Rain gardens you can build by a professional or yourself. There's relatively little liability associated with it," he said. "It's not recommended you build a roof-top garden on your own."
Preserving, recycling and filtering water through the ground rather than rushing it toward rivers and streams can prevent water shortages and flooding, he said. Another issue is the pollution stormwater brings to streams when it is allowed to roll off roofs, parking lots and driveways.
Installed properly so they direct rainwater away from houses, retention programs can help keep basements drier, too, he said.
With the cooperation of the landlord, de la fleur has installed rain barrels, cisterns and something called gravel grass as well as the rain garden and roof garden at a two-flat he rents with his wife, Cathy Haibach. The couple hopes to buy a home in Chicago, and he dreams of demonstrating indoor methods of sustainability there.
Now he maintains a volunteer web site to explain his project and answer questions from homeowners. At his job with Conservation Design Forum in Elmhurst, he works on similar but larger commercial and government projects.
"People are interested in doing or getting started," he said. "They send e-mails saying 'This is what I did and I wonder if it is right.'"
Many of these methods have been used for many years in Europe, said de la Fleur, who is from Germany.
And he thinks it's possible the United States isn't really trailing Europe any more in efforts to save the environment.
He has been in this country for six years and has noted amazing changes in that time. For example, the city of Chicago urges building owners to install green roofs, and engineers are embracing porous pavements.
"If we continue at this rate we will leave Europe in the dust," he said.
And what do the neighbors think about a yard full of tall prairie plants?
They love it, he insists.
"I got mentally ready for complaints and questions from the city council. None of that happened."
One person who made a negative comment responded later than she had done research and changed her mind, he said.
Here is what de la fleur has built on his yard:
The landscape architect uses several rain barrels. For example, on the south side of his house, three are tied together to capture water from the roof. Any extra is guided through a channel to the front yard rain garden.
De la fleur built rain gardens in the front and rear yards, but they are difficult to see. That's because they are really just basins dug a little lower than the surrounding area.
In his front yard, the lowest spot is only a foot below the rest of the yard, while in back it reaches a depth of 15 inches. And when the whole yard is planted with prairie grasses, native flowers and sedges, these areas don't really show.
In fact, despite heavy rains, de la fleur has not been able to catch water pooling in the rain gardens. He even biked home from work during a rainstorm to try to shoot a photo.
Native grasses and sedges are the work horses that take carbon from the air, build soil and keep it open so water can sink in and be filtered, said de la fleur. The flowers help but are more for looks.
And the beloved suburban turf grass does not perform the work of a natural sponge as well.
De la fleur's preparation of the rain garden included herbicide to kill the turf and weeds. Then he installed a ¼- to -inch layer of sand and prairie plant seeds.
He did not choose wetland plants because they are much fussier and need water flowing through their roots.
"For gardening they are a high-risk proposition, too much of a risky investment. It's never really wet in there," said de la fleur.
Prairie plants need sun, and if your yard does not have sun at least half a day it might not be able to host a rain garden. However, often the landscape architect finds that shady lawns are caused by trees, such as buckthorn and mulberries, that should be removed anyway.
While it may seem obvious, the fact that water flows downhill is an important rainwater management technique that homeowners need to understand, he said.
De la fleur also sees annual burns or fires, which are done with a license from the Illinois Environmental Protection Agency and permission from the local fire department, as an important part of growing the garden. The gardener who does not want to burn will have to start with plants rather than seeds and do extensive weeding, he said. Without burns thatch will build up in the yard.
Cutting the plants back to near the ground in the spring is a good idea whether the gardener uses fire or not.
Building a roof garden is a little bit like rocket science, said de la fleur.
You need waterproofing and something to protect the waterproofing. Then you need a carefully engineered growing medium that retains moisture and stability but drains freely. He installed 3 inches of growing material - expanded clay, a little soil, sand and loam - on top of 1 inch of drainage aggregate or special gravel. The 250-square-foot roof garden over the home's enclosed front porch captures 50 to 75 percent of the rain that strikes it, he says.
As you might guess, this is a harsh environment, and the plants have to be tough and drought tolerant. He chose sedums and blue gamma grass - native to the western great plains - and Mexican hat flowers.
The roof can be flat or pitched as much as 45 degrees. As bonuses, plants protect the roof from sun and serve as insulation. They also help combat the increased heat generated by metropolitan areas.
Gravel grass is planted in open-graded aggregate or gravel with sandy loam. It drains better than regular gravel. It can be used as temporary or occasional parking either at a home or larger institution.
Because of the quick drainage, drought-tolerant grasses such as buffalo grass and side-oats grama are used, and de la fleur recommends adding drought-tolerant fescues and clover. This has been tried for overflow parking for the Kane County Cougars.
The pavers are set a ways apart with stone chips in the spaces between them. The underlayment is porous such as gravel and stone chips.
Although de la fleur probably doesn't need that much water, there is a pump on an existing cistern that is 8 feet deep. Homeowners could use such water for laundry and to flush toilets, he said.
Areas of turf or blue grass are needed for parties and for children to play. Thus, de la fleur's landlord had him keep a few small areas for any eventual tenants.
Marcus de la fleur's web site is www.delafleur.com
Here are some of the grasses, flowers and sedges that Marcus de la fleur has planted in his rain garden.
Copper-shouldered oval sedge
Joe Pye weed
Little bluestem grass