This article first appeared in INHF's Summer 2008 magazine.
Terry Haindfield/Iowa DNR |
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Heritage Valley, INHF’s newly protected area along the Upper Iowa River, suffered substantial flooding in June. Participants in our August 23 BioBlitz gathered data on the flood’s impacts on the 1,224-acre site’s land, plants and wildlife, which will be compared to BioBlitz data from 2007 and 2009. Watch for updates in future magazines. |
How should we make sense of the Great Flood of 2008? Why was the damage so much greater than past floods, and what can we do about it? Having witnessed nature at its worst, Iowans are called to be our best as we rally to prevent such destruction in the future. Learn more.
Some say recorded history isn’t long enough to safely predict extreme floods. Others claim we have just glimpsed our future after global climate change. Both points may be true, but they can also lead to despair and paralysis. Fortunately, explanations nearer at hand offer more hope.
Water tied to land
Let’s get back to the basics: Water management requires land management. And we must do a better job of both.
Consider obvious land changes of the last 100 years: converted prairies and wetlands, cleared woodlands, drainage tiles, straightened streams, leveed floodplains, and ever-more roads, roofs and driveways to shed more rainfall. While we have added buffers along some waterways and restored some wetlands, they are not enough when millions of acres now act as a chute rather than a sponge.
Consider that intensive row-crop farming and excessive tillage have long been depleting the very soil qualities that can absorb and store rainwater. Despite some improvements in recent years, studies show about 30 percent of cropland is still eroding at excessive rates.
Consider that cash crops used to include oats and hay, which provided deep-rooted vegetation as well as spring and fall soil cover to prevent rapid runoff and erosion.
Land changes suggest needed policies
These factors go far to explain why historic flooding is not a reliable predictor of future flooding. They also suggest basic, common-sense policy and management changes we can use to mitigate the impact of deluges to come, and, as a bonus, help slow climate change.
- Encourage and demonstrate the use of cover crops, continuous no-till planting and grass-based livestock systems that maximize infiltration.
- Reinvent the Conservation Reserve Program for new environmental and economic realities.
- Enforce existing soil conservation requirements in state and federal law.
- Move crop production out of flood-prone areas to avoid repeatedly subsidizing crop losses and repairing flood damages. Convert floodplains to forests, grazing land and wildlife habitat.
- Mandate and implement urban storm water ordinances that set infiltration and water-holding requirements, especially for new development.
Communities are again seeking state and federal help to raise new and bigger levees. Some projects will make economic sense, but many won’t. The unfortunate consequences of levees are that they raise downstream risks while offering a false sense of security. They entice people to take unnecessary risks and do nothing to address the upstream sources of the problem.
Previous record rains fell on an Iowa landscape very different from today’s. The quantity and speed of this year’s floodwaters are, in large part, a consequence of our collective land management decisions. If we continue to neglect our land, we cannot afford to build levees high enough or strong enough to contain the next great flood.
For more information, e-mail Duane Sand, Public Policy Director, or call (515) 288-1846.