A good place to run
Four years ago, Skokie, Ill., resident Debra Shore wanted to replace her paved driveway with a permeable surface — gravel held in place by a plastic grid system. Shore estimated that the surface would prevent 10,000 gallons of rainwater from entering Skokie storm sewers every year.
She contacted Skokie village offices about obtaining an appropriate permit, only to discover that the suburb, located just north of Chicago, only allows concrete, asphalt or paving brick driveway surfaces. Shore reluctantly decided to maintain her paved driveway.
Even so, Jim Ochi, civil engineer in public works for Skokie, says there are some drawbacks to permeable surfaces. “They have to be vacuumed twice a year, or they end up getting plugged up, and then it’s just like a regular paved surface. They require a lot more maintenance, [including weed control],” he says. Snow removal can be more challenging as well. If the village allowed permeable surfaces for privately owned driveways and parking lots, he says, “you would end up with a hodgepodge of materials that would be very unsightly.”
Though seemingly insignificant, that driveway dilemma illustrates how some municipal ordinances can conflict with practices suggested by county and state stormwater management agencies to control runoff. And Shore considered the issue important enough to make it a pivotal element in her campaign for a seat on the Chicago Metropolitan Water Reclamation District’s nine-member board in the March Democratic primary.
Rain runs off driveways, rooftops, paved streets and parking lots, picking up contaminants, including oil, pet waste and trash. Discharging that water directly into storm sewers degrades water quality, causes flooding and, at times, mixes with raw sewage.
Congress aimed to prevent those problems when it changed the Clean Water Act to include storm discharges in the National Pollutant Discharge Elimination System (NPDES) permit program. As a result, the Environmental Protection Agency developed requirements for NPDES permitting. For example, developers and property owners must list measures to reduce runoff and remove significant pollutants from the stormwater.
A variety of suggestions for stormwater control sprang from the federal requirements and developed mostly at the county level across the United States. Washington and Maryland are examples of states with well-developed stormwater best-management-type practices, and other states, like Illinois, have followed their lead, organizing a single agency to oversee federal permitting and clustering county governments in regional stormwater management districts to promote good management practices.
While best practices vary considerably by region, they include some impressive new strategies. “What’s traditionally happened is that people have been rushing to get water down stream, but in the last 15 to 20 years, they began to realize they couldn’t do that without sacrificing water quality and causing flooding — so they started building retention ponds and letting water out at restricted rates,” says Kerri Leigh, director of Environment for the Natural Resources Group of the Northern Illinois Planning Commission. The commission works with local governments, encouraging them to adopt best practices for stormwater control.
“Best management practices [such as building retention ponds] protect streams from having too much flow by increasing the amount of permeable surfaces,” Leigh says. “Those surfaces also have a cleaning function.” Certain techniques to manage stormwater are not viable, such as in Illinois where retention ponds attract geese and other waterfowl as well as their droppings, Leigh says.
Guide for developers
Cook County, Ill.’s Metropolitan Water Reclamation District of Greater Chicago provides a manual for developers and property owners that suggests several ways to reduce runoff. “Guide to Storm Water Best Management Practices: Chicago’s Water Agenda” lists several ways to control stormwater runoff, including permeable paving surfaces for parking lots, low use driveways, access roads, fire lanes and alleys, along with filter strips planted with flowers and native plants that absorb and filter run-off.
Other recommended stormwater management practices include colorful rooftop gardens, like the one on top of Chicago’s City Hall. The 20,300-square-foot garden was designed to cool the building and absorb rain.
Green roofs, like City Hall’s, are sprouting up all over Chicago — on schools, museums, businesses and homes — thanks to a program started by the city’s Department of Environment, which provides $5,000 grants for the gardens.
One drawback to green roofs is that they require stronger structural supports than conventional roofs. The grant money does not go far if architectural modifications are necessary. But, fortunately, many other options are available, such as disconnecting downspouts from sewers and allowing the water to drain into lawns or collecting runoff in rain barrels, using it to water plants and trees.
Chicago’s manual also suggests planting more deeply rooted native plants to absorb water and prevent soil erosion. It also highlights attractive stone-laden drainage swales that absorb water.
Expansion drives many efforts
Similar efforts to control stormwater runoff exist in other communities across the country, such as Prince Georges County, Md., which sets the bar for best management practices, according to Leigh. New construction and flood damage from hurricanes inspired its stormwater control efforts, says Christopher Akinbobola, associate director of the county’s Environmental Services Division. Prince Georges County includes 26 municipalities, many of which are undergoing considerable expansion, pushing for zero storm runoff with all projects.
Growing population has moved Kane County, Ill., to insist on low-impact development. That approach creates clusters of new buildings on rises and hilltops to minimize drainage problems, uses permeable parking surfaces and preserves existing wetlands and open spaces to absorb stormwater runoff, according to Paul Schuch, Kane County’s director of water supply resources.
The recently constructed Fox Mill development in Kane County incorporates all of those things and goes even further, collecting wastewater, treating it and applying it to a nearby hayfield. “We’re trying to complete the hydrology cycle,” Schuch says. “We’re doing this to pump up our aquifers as opposed to pumping the water downstream to the Gulf of Mexico.”
Because Kane County does not have access to Lake Michigan for drinking water, “our goal is to make this county self-sustaining,” he says. His department also has begun analyzing natural groundwater flow and existing aquifers to prevent their destruction from development.
Washington also is working to protect its water quality. As part of its NPDES permitting process, the state requires installing hydro separators in new storm sewer systems to remove waste oil and sediment from the water stream. Although King County, Wash., publishes a best practices manual, its state Department of Ecology produces two separate manuals, recommending best management practices for its rainy western half and others for the dry eastern half.
Integrating wetlands restoration
Likewise, Florida is divided by watershed issues and produces a best practices manual for the northern half of the state and one for the southern half. But, wetlands restoration affects the entire state, and because the stormwater rules apply almost exclusively to new development, wetlands preservation is an essential element of stormwater management, flood control and water quality.
Florida’s best management practices not only include wetland preservation but “constructed wetlands,” which are developed to retain and purify water. Some of those operate like isolated wetlands, because they do not flow into streams or oceans.
The state has jurisdiction over both connected and isolated wetlands, except within Northwest Florida, because of fiscal constraints. There, wetlands jurisdiction is limited to only those that are connected, unless by some chance an isolated wetland is part of a constructed stormwater system.
Because isolated wetlands are regarded as natural retention ponds and filters for runoff, the relationship between them and stormwater control is growing. Isolated wetlands are found beyond southern states, including the Northeast and Midwest where they are called marshes, bogs, sloughs, fens, small glacial lakes and prairie potholes.
Despite their value in flood control, wetlands have become increasingly vulnerable to development. A 2001 U.S. Supreme Court decision, which removed U.S. Army Corps of Engineers’ jurisdiction over isolated wetlands, set off a series of requests from businesses to remove the Corps from making decisions in areas they wanted to develop, according to the Illinois Chapter of the Sierra Club. The organization noted that within a year of the decision, developers in Cook County filed 84 such requests.
States such as Wisconsin, Maine and Massachusetts have recognized the value of isolated wetlands for preventing flooding and maintaining water quality, and have established protective laws that stop their dredging, draining or filling altogether or require special permits for such activities. “Isolated wetlands are crucial to the prevention of flooding … they operate like sponges,” said Illinois State Rep. Karen May last fall in a phone interview after the defeat of her proposed protective legislation. “They clean and filter water and improve water quality — I call them the kidneys of the ecosystem — they replenish our aquifers.”
Susan DeGrane is a Chicago-based freelance writer.