Rising waters raise concerns about flood control measures
Heavy rains and high waters in the nation's midsection are focusing attention on flood control. Is it adequate? Is it well thought out?
Homeowners who battled floodwaters from Oklahoma to Michigan this past week might say no. And increasingly, a number of local officials and water experts agree.
``Flood control measures are not adequate,'' says Brent Blackwelder, vice-president of the Environmental Policy Institute in Washington, D.C.
``We need regional planning on a much larger scale,'' says Joanne Alter, commissioner of the Metropolitan Sanitary District of Greater Chicago. ``Flooding doesn't know any political boundaries. And yet our taxing authority [and] our planning authority stop at the township line or the county line.''
Current measures were clearly not enough for the heavy rains of the past two weeks. Rivers overflowed and stormwater runoff backed up, causing at least 11 deaths and millions of dollars in damage in Ohio, Michigan, Illinois, Iowa, Missouri, Kansas, Arkansas, and Oklahoma. In the Chicago area alone, damage is estimated at $35 million or more.
Solutions run along two main lines: big engineering projects, such as dykes or levees, and nonstructural options, such as preserving wetlands. When the rains began to fall in the Chicago area in mid-September, both types of water systems kicked into action.
In conventional terms, the Metropolitan Sanitary District's Tunnel and Reservoir Project is an engineering marvel. Dubbed ``Deep Tunnel,'' the 47-mile underground system held nearly 1 billion gallons of excess water at the peak of the storms, preventing further flooding. But when it reached capacity late last week, engineers reluctantly had to allow raw sewage to flow into Lake Michigan.
``We had a billion [gallons'] worth of storage and we needed 360 billion,'' says Bill Macaitis, the district's assistant chief engineer. The $2.4-billion sewer and flood-control project is only half finished because of complaints about its expense. If completed, it would include a 360-billion-gallon network of reservoirs, capable of handling most floods.
While Deep Tunnel was collecting stormwaters last week, an innovative commercial development in nearby Itasca, Ill., was largely unaffected by the heavy rains. The Hamilton Lakes project suffered no flooding because its largely nonstructural system was designed to collect and store rainwater, leaving huge areas of lawn where water could seep through.
``Water is really something that takes up space,'' says Jack Sheaffer, president of Sheaffer & Roland, the firm that designed the Hamilton Lakes system. ``And where we put it is the sole role of management. ... If we don't store it underground, we store it on the surface and we call it flooding.''
Despite various control projects, flood damage in the United States has grown every decade this century because of increased development, according to several studies. Not only are buildings placed in or very near flood plains, the construction of new streets and parking lots leaves fewer places where rainwater can be absorbed by the soil.
Some flooding is impossible to control cost effectively, says Kyle Schilling of the US Army Corps of Engineers Institute for Water Resources.
But critics say the federal government should pay more attention to nonstructural solutions, such as banning new construction in flood plains, flood-proofing some existing structures there while moving others.
Mr. Blackwelder also suggests preserving upstream wetlands, recharge areas, and green spaces along rivers, which help control water flow naturally.