This year's high water on the upper Mississippi has restarted a debate that began during the record floods of 1993. Should levees be higher and stronger, or should homes and businesses be moved out of the flood plain?
That question has no easy answer, in the Mississippi Basin or any other flood-prone region. Squared off are the natural inclination of humans to settle, farm, and develop fertile and scenic riverside land, and the inclination of great rivers to seek out their historic channels. After an extraordinary rainfall, the cost in disrupted lives and damaged property can be high - with taxpayers picking up much of the tab.
Flood walls and levees are designed to reduce those costs. And there's little question they can be locally effective. The media spotlight in this year's flooding has been on Davenport, Iowa, the only upper Mississippi urban center without permanent flood protection.
The value of some form of reliable protection for established city centers is hard to refute. But efforts to build ever higher levee walls around expanses of mostly open flood plain so that developers can move in - that's another matter.
A good deal of the latter is currently under way in the St. Louis area, particularly on the flood plain of the Missouri River, near where it joins the Mississippi. Malls, businesses, and residences could proliferate on land that was underwater eight years ago.
Local planners, and the Army Corps of Engineers, which builds the levees, may have no doubt the land can be made secure. Mighty rivers, however, offer no guarantees.
Following the 1993 floods, a joint federal-state program was launched to buy land in the flood plain and preserve it as open space - to be used for recreation and wildlife habitat, and occasional expansion room for the Mississippi and its major tributaries.
The program has slowed, and could slow more. It would be wiser and ultimately more frugal to reclaim flood-plain land now in order to avoid higher flood-damage costs later.
(c) Copyright 2001. The Christian Science Monitor