Published: June 27, 2008 07:06 pm         

Flooding raises question of effects of watershed changes

The Back Porch column

An act of God. Or was it? A story last week in The Washington Post suggests topographical changes to the Midwest contributed to the devastating floods in Iowa and along the Mississippi River. The 15 inches of rain played a role, too.

Kamyar Enshayan is a member of Cedar Falls City Council and director of an environmental center at the University of Northern Iowa. He told The Post the changes to the land caused by agricultural practices have changed the land’s ability to absorb water.

He specifically noted the removal of prairie grass for plowed fields, underground drainage systems in fields, straightened streams and creeks, reduction of wetlands and the development of flood plains.

Jerry DeWitt is director of the Leopold Center for Sustainable Agriculture at Iowa State University. He told The Post that farmers are putting land closer to creeks and rivers into production. The practice pushes water from fields into the waterways faster without a buffer zone between farming fields and waterways.

The Post story reports the underground drainage systems have the same effect in pushing water quickly to waterways instead of letting it pool in fields. Combine that with the fact that corn will cover one-third of the state this year — in response to the ethanol boom — and that’s a lot of lost absorption.

Lyle Asell works for the Iowa Department of Natural Resources. He told The Post that from 2007 to now farmers took 106,000 acres of state land out of the Conservation Reserve Program, a federal program that pays farmers to leave land uncultivated. That land could have absorbed some of the rain if it had been covered with deep-root grasses.

During the 1980s and 1990s, Iowa led the nation in flood damage, Asell said. As creeks and rivers fill with sediment, their water-carrying abilities are diminished.

A West Virginia Supreme Court opinion Thursday in two cases related to the July 2001 flooding in the southern coalfields acknowledges that changes to watersheds could contribute to flooding.

The high court reinstated a jury’s verdict in one Raleigh County case and reinstated the claim of plaintiffs to pursue litigation in another Raleigh County case.

In the court’s discussion of the Upper Guyandotte River Watershed, justices noted the stricken testimony of one expert witness regarding the diminished absorption rates at Slab Fork caused by 245 miles of timbering skid roads. Yes, that’s 245 miles.

Footnote 4 of the opinion said evidence in the Slab Fork case showed that in the decade preceding the July 2001 flood, Western Pocahontas Properties removed 40 percent of the timber from the 22,650-acre watershed. That’s a lot of trees with deep roots that absorb a lot of water on steep hillsides.

The very definition of runoff is water that has nowhere else to go when it can’t be absorbed.

Some people are comparing this brief economic downturn to the Great Depression. That time also saw the Dust Bowl, which gave birth to a federal conservation program. Perhaps it’s time to revisit the fruits of that terrible time before conditions really do get that bad again. Land use must be part of that review.

Developments suck up the best farmland and the level land along creeks and rivers. To continue farming, farmers suck up the best wetlands and push farming into the hills or closer to rivers and creeks. The cycle must be stopped.

Enshayan told The Post: “Cities routinely build in the flood plain. That’s not an act of God; that’s an act of City Council.”

— Young is a Register-Herald columnist. E-mail: ynerissa@verizon.net.

© 2008 by Nerissa Young