Soft alternatives to soft-headed flood control
July 29, 1993
As a boy I was fascinated by moving water. A beneficent Providence would have seen me grow up to be a hydrologist or civic engineer; instead I just wrote columns about stormwater management. This one, I believe, was inspired by research I’d done on the topic for the American Planning Association’s magazine, Planning.
Everybody talks about floods, but nobody does anything about them. Well, not quite. The Army Corps of Engineers uses its considerable expertise to make them worse, and local governments work even harder to make them expensive by allowing people to build houses, businesses, and farms on flood-prone land.
All together now: Isn’t there a better way?
Yes. “Soft” engineering approaches to urban flood control have been successfully tried in Tulsa, Denver, Boston, and Denver. California’s Urban Creeks Council has been especially busy taking creeks out of culverts, revegetating eroded stream banks, redirecting flood flows to storage and groundwater recharge areas, and creating wetlands. The work is paid for by local contributions and volunteer help, plus money from a state bond issue that in 1992-93 supplied $1.3 million for twenty projects.
Restoring wetlands is tricky—they are as fickle as an alderman, and more complex—but most other stream functions are amenable to human repair. An eroding, denuded stream bank can be restored by wattles or fiscines or reed mats or root wads (upturned tree stumps), even concrete rubble interlarded with soil. Anything but high-tech, these techniques have proven durable and cheap.
Not that slickly engineered solutions are the sole province of the slide-rule types. Leslie Sauer, a principal of Philadelphia’s Andropogon Associates, is one of the new restorationists whose admiration for nature is practical rather than merely mystical. They realize that the meanders, grassy banks, and willows are not only ecologically correct but comprise a subtle and cost-efficient form of stream engineering.
New technologies are giving ecologically-minded restorationists tools that can begin to cope with nature’s complexity. Sauer has noted that computer modeling now makes it possible to engineer particular solutions for particular streambeds. New materials mean new possibilities; Andropogon has used a special porous asphalt to pave parking lots, turning them into groundwater recharge areas while reducing runoff to overburdened storm sewers.
Springfield’s most scenic spots—Lincoln, Washington, Bunn, and Bergen parks, Oak Ridge Cemetery—are stream courses that were protected by the city from development. Today’s generation of city officeholders—they do not deserve the term ‘leaders”—cut very poor figures next to their foresightful predecessors. However it is not too late to recoup some of the landscape values that recently have been thrown away as a result of such narrowly conceived “improvements” as Veterans Parkway.
As part of my daydream program to restore as many segments as still exist of the metropolitan area’s natural stream system, the city would not only ban building in floodplains but buy out existing properties and clear them. (Corps of Engineers money would be well spent here, since every gallon stored upstream is a gallon the Corps won’t have to control downstream.) Developers would be obliged to either build on-site retention systems proportional in size to the amount of land paved by a project, or contribute to a fund for public flood control projects. The individual homeowner can do her small part by installing rain barrels on downspouts to catch water for gardening and other yard use.
It isn’t hard to envision what such a program might lead to in Springfield—willows along Wabash west of Chatham Road, for example, or a marsh where the egregious Montvale development was proposed. Alas, as the teeth-gnashing over grass clippings proved, green is not the typical Springfieldian’s favorite color. Floodplains are dry most of the time, very wet sometimes, and tend to smell in between. They collect silt—that is part of their function—which is inconvenient in places like Washington Park, whose lower lagoon had to be dredged a few years ago at some considerable cost. Reforested creek branches will attract wild animals, and wild animals attract trouble when they show up in people’s backyards.
Worst of all from a political point of view, natural floodplains take up real estate. Pipes and levees are the methods of choice for controlling floodwater not because they work better but because they take up little land, and less land for nature to use means more for developers to sell. The land developer’s thirst for profits is matched by that of city officials everywhere, who are more than happy to impoverish the local ecology to enrich the local property tax coffers. Redwing blackbirds don’t vote.
The net cost of restoring a natural. stream system would be reduced by the value of the other benefits it would produce. Build a conventional flood control system and all you get for your money is a flood control system; restore even bits and pieces of a stream system and you get green space and wildlife habitat and fishing spots and trails.
Hey Associates, the Chicago-based water resources consultant, is working with the City of Chicago to restore its vanishing historic wetlands. Hey also manages the Des Plaines River Wetlands Demonstration Project in suburban Chicago at which State of Illinois agencies as well as the U.S. EPA, U.S. Army Corps of Engineers, and researchers from fifteen universities are trying to restore a natural flood control system in that highly unnatural area. These test wetlands function as habitat as well as research plots and have attracted birds such as the least bittern and yellow headed blackbird, species endangered in Illinois. In Colorado, recreational green-ways have been reconfigured to recharge local groundwater or to treat stormwater and secondary sewage plant effluent.
A sensible approach would seek to squeeze extra value from each public investment by combining habitat, scenery, and recreation with flood control where appropriate. A golf course or soccer complex is the perfect thing for a floodplain. (Case in point: the Illini Country Club course, which periodically relieves the Jacksonville Branch of its burden of stormwater.) Similarly, wooded stream corridors make perfect sites for bike trails.
Alas, while Nature has been into regional government for a long time, humans still haven’t caught on. The power to plan, purchase, and develop land for public use is invested in a half-dozen local agencies. The agency that deals with flood control is not the same agency that deals with recreation, and neither deals with zoning.
The Springfield Park District, for example, bought forty acres of a former upland farm for a new park for the city’s metastisizing west side. Near this flat, barren plot, houses are being built on picturesque lots in stream valleys. As long as we persist in building parks where houses should go and houses where parks should go, we ought to expect Nature to scold us once in a while for our stupidity. ●