There was a day when basements in houses were intended to flood and hold rain until the sewers were ready to take the water, recalls Richard V. Doherty.
Nowadays, however, basements are improved and owners won`t accept a foot of water in the rec room as a way to handle storm runoff. Developers must supply a water-detention or retention plan.
And increasingly engineers are using natural areas as flood basins, and scientists are experimenting with growing things that one of them describes as ”plants that do constructive work” in hopes of halting flooding and erosion while beautifying the areas involved.
Doherty, public works director in Lombard, now wrestles with more sophisticated water problems such as retention and detention ponds, surcharging sewers, proper street drainage and preparing for a Lake Michigan water supply. But flooded basements, streets and yards are still a problem in his town and others, as the heavy rains of last August proved.
Instead of basements, engineers today use ponds to help control water runoff. In dry weather these can be office building and shopping center parking lots or parks and playing fields, anything that can hold and slow down storm water. Or they can be wetlands or small lakes, such as those at Green Trails, a large Lisle subdivision whose ponds add beauty to the setting.
Ponds, says Elmhurst City Manager Thomas P. Borchert, ”help the storm water system work right” and even may reduce creek flooding. In a typical industrial park use, such basins hold rain that otherwise would likely make sewers backup, Borchert says.
Without ponds, flooding can`t be prevented, say Doherty and others who work with developers to solve water problems. But some storms will exceed the ponds` capacity, and nearby homes and other buildings will still suffer.
It isn`t economically justifiable to construct ponds and sewers for a once-a-century storm, and indeed some of those in Lombard overflowed last August because they were designed for so-called 50-year storms, Doherty says. He wouldn`t want to spend what would be required to prevent all possibility of flooding, he adds.
But ponds have problems. They may constitute a danger to children. There may be too little land left in built-up areas for a proper pond; so one with steep sides is built and it is hard to get vegetation to grow on the slopes. This leads to erosion of the sides and filling up of the pond, reducing its capacity and imparing its functions, notes N.J. ”Pete” Pointner II, president of Planning Resources, a firm that works for several Chicago suburbs.
Pointner and others are trying to get developers and government officials to take a new look at ponds and the regulations governing them. ”You could get less maintenance and something that would enhance instead of detract from the property and add recreational values if they were properly designed,”
Pointner argues.
Now, he explains, Du Page County requires that ponds be on a separate lot in a subdivision called an outlot. ”The problem is that with a small subdivision or developer you do not have enough people in a homeowners association to maintain it.”
But if developers had the option of allowing every lot to touch the center of the pond or its shores, ”everybody would have lake frontage and you could allow for more creative landscaping” with less maintenance, Pointner says.
At Morton Arboretum, Research Director George Ware has been experimenting with running dwarf willows to help control erosion and beautify ponds. A running shrub is one whose roots spread and hold the soil.
Other erosion-control measures include riprap, which are loose stones;
gabion weirs, which are dams made of cages containing rocks; and grass. But Ware notes that stones wash out, whereas plants with good roots are less likely to do so.
Ware said three willows show promise, and he gave one of them to the Ginger Creek Homeowners Association in Oak Brook three years ago for use on islands that were having shoreline erosion problems.
The types are sandbard willow, Streamco and a hybrid dwarf from the Swiss Alps known as Salix cottetii.
Ware says that ”bank damage usually occurs in early spring and the willows resume growth then and begin to repair the raw spot with new shoots and interlaced roots.”
Pointner notes that ”the wind blows the water on even a small pond against the edges and tears them, weakening walls so they fail or look bad. It is hard to maintain the ponds because of the silt and dirt that fill them
(and) shallow water warms up and stagnates and you get moss, algae and associated odors.”
”It looks and smells bad,” he says.
