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Altered terrain almost beckons disaster
Take note, Minnesota: A little foresight in managing wetlands might have mitigated catastrophic flood damage to the south.
By DENNIS ANDERSON, Star Tribune
Last update: June 19, 2008 - 10:59 PM
Case in point: the Iowa floods, with damages that will total in the billions of dollars -- were all predictable, if not preventable.
Like Minnesota, Iowa has been almost completely transformed since settlement. According to the Iowa Department of Natural Resources, 95 percent of that state's wetlands have been drained or filled. About 75 percent of its forests have been cleared and more than 99 percent of its prairies have fallen to the plow.
Additionally, most natural vegetation -- typically called buffers -- along rivers and streams has been removed, lowlands have been tiled and streams channelized, or straightened, to provide more tillable land.
And more floods.
For which a lot of Iowans -- and you and I -- are about to be billed. Again.
Ironically, Congress only recently has passed its latest version of a federal farm bill. This measure, whatever its other virtues or vices, is sure to ensure more flooding. Not just in Iowa, but throughout the Mississippi River watershed, including vast portions of Minnesota.
This huge and complex bill, like its predecessors, promises to continue mistakes of the past. As sure as rain will fall, corn acres and soybean acres encouraged in floodplains and protected by the bill will facilitate inundations similar to those that have devastated Iowa towns and rural areas in recent days.
The reason is simple: Thanks to modern agriculture -- which happily defers its flooding and other "business expenses'' downstream to society at large -- the landscape's hydrology has been altered so dramatically that water -- be it snow, snow melt or rain -- will continue to be drained swiftly from the land by a vast system of tiles and ditches.
Rivers on the receiving ends of these lattice works will in turn rise beyond capacity, and flooding will ensue.
A group called The Wetlands Initiative, with studies that were funded in recent years by the McKnight Foundation, believes society should change course in at least two ways to prevent costly floods.
First, restore the natural hydrology in the floodplain and reconnect some of the leveed floodplains to the parent river to take advantage of the flood storage potential that wetlands provide,'' a WMI report advises.
Second, where lands are frequently flooded, eliminate economic activities that are adversely affected by inundation. In short, the bottomlands of the Upper Mississippi River Basin should be returned to their natural state, which would hold floodwaters for weeks, if not months, at a time. Levee districts could be used for strategic flood control by capturing flood peaks when and where needed.
Unfortunately, such changes are unlikely, even though damage totals from the current floods might rival those of 1993, when the cost alone to Iowa, Illinois and Missouri was $12 billion.
Not incidentally, those three states also have drained the most wetlands, 87 percent on average.
In Minnesota, the best chance for improved watershed management and fewer, less severe floods, probably lies with dedicated conservation funding, which will be on the statewide November ballot.
If approved, some $200 million a year will flow toward better wetland, upland and watershed management.
Still, as noted at the outset, it's unlikely people anytime soon will successfully demand a stop to agricultural practices that virtually guarantee flooding -- even at great expense to them, financially and otherwise.
Dennis Anderson • email@example.com