Despite centuries of attempts to dam, straighten, channelize and levee America's rivers, humans have not kept flood plains from floods, says UC Davis geologist Jeffrey Mount. In fact, he says, the 1997 flooding in the Pacific Northwest, California and the Midwest showed that such artificial controls make matters worse, not better. In an address this month at the annual meeting of the Geological Society of America in Salt Lake City, Utah, Mount will call for more realistic, geologically sensible approaches to reducing flood hazards -- and to co-existing with them. Mount makes three key points: 1) Geologists and engineers know that rivers will flood uncontrollably, "but we have failed to communicate this to a populace that either does not understand it or, for various reasons, refuses to hear it." 2) Flood-plain policy and engineering decisions are being held hostage by predictions of flood frequency and the so-called "100-year flood event." These predictions are unreliable, yet are "the distributional tail that tends to wag the flood-control dog." 3) Traditional flood-engineering measures conflict with the natural function of rivers. "Yet by promoting development of the natural flood plain, these approaches have the unwanted effect of increasing flood damages, rather than reducing them."