Creeks in Revolt

A middle-class family with several children find their dream home in a new metropolitan subdivision, fall in love with it and buy it. It's really more than they can afford, but the couple decide to stretch their budget to provide more space for the children they dote on. The pretty house has a large yard and the kids will love that, too.

It's midwinter when they move in and everything is fine. But when spring comes, the little creek at the back of the yard turns into a roaring torrent. It takes a while, but the couple begins to realize the creek is actually devouring their yard. Two months later half of the backyard is gone, and the creek is still eating its way toward the house. They call in an engineer, who suggests building a dike or retaining wall at the back of the yard. Cost: up to $100,000.

The couple doesn't have the money; developers of the subdivision claim innocence in the whole affair. City managers sympathize with the couple, but take no responsibility and offer no solutions. The whole thing will probably end up in court, and there will be no winners, whatever the outcome.

In many of Missouri's rapidly-developing areas, once-docile local streams are overloaded with all of the water running off of new roads, parking lots and all the other hard surfaces that make subdivisions and shopping malls possible. Homes, buildings and other structures built too close to these streams may be threatened or destroyed.

Often a quaint, seemingly-harmless creek that you could "step over" only 10 years ago turns downright mean. Although most people who live near these streams are aware of visible problems, few understand the causes or realize the consequences that these problems have on the ecology of local streams.

Causes

What happens to streams in developing areas? Simply put, their watersheds change. Natural streams in undeveloped watersheds are covered by natural vegetation, mostly forests or prairies. This land retains a great deal of rainfall much like a sponge, slowly releasing it into nearby streams and creeks. Streams adapt to this naturally controlled runoff over thousands of years and form meandering channels with minimal erosion.

When parts of a watershed are cleared for urban development, its water holding capacity is greatly reduced. Urban areas, in particular, are covered with vast expanses of "impervious surfaces," including roads, parking lots and rooftops. These surfaces absorb little or no water.

When it rains, water