Protect Wetlands to Cut Flooding

One of the first sounds I learned to imitate as a child was the UNKachunka-UNKachunka of a pile driver, pounding steel pilings into unstable ground before anyone built a new warehouse, medical building, apartment complex or any other major structure near the waterfront in my hometown of Norfolk, Va. It didn't even have to be at the waterfront, since much of the original town was built on wetlands that had been filled in decades and sometimes even centuries before I was born.

Midwestern children might notice wetland loss differently. They might admire the rich black soil of lowland farms, often wetlands drained by piping water into drainage ditches to create highly productive, now-tillable soils. And like communities on glacial terrain throughout the Midwest, a portion of my Midwestern neighborhood is built on filled-in wetlands.

The past 30 years have brought wetlands -- historically treated as waste lands -- into greater public sympathy. Fishermen and duck hunters have become vocal about wetlands' ecological roles as breeding grounds for many fish species and habitat for migratory waterfowl. Engineers document reduced siltation of dams and channels. Atmospheric scientists assert that because wetlands store carbon in soil and plant communities, they reduce carbon dioxide released into the atmosphere, thus helping reduce global warming.

But another crucial wetland function has recently caught Midwesterners' attention: flood mitigation. The terrible floods in recent weeks highlight a central hydrologic function that wetlands can play. They function as a sponge, absorbing potential floodwaters, slowly releasing them back into the streams and rivers they feed. One acre of wetlands is estimated to store up to 1.5 million gallons of floodwaters.

There are many factors influencing flooding, including location of communities and new developments in flood-prone areas; increased impervious surfaces that decrease absorption; deteriorating levees and other flood-control structures; and changing weather patterns, possibly as a part of global climate change. One big factor is the loss of wetlands.

Today approximately half of the wetlands remain from those estimated to have been in the lower 48 states in the 1600s. Wisconsin is estimated to have lost over 50 percent of its wetlands in the last 200 years -- Illinois 85 percent, Iowa 89 percent, and Minnesota 42 percent. Much of that loss occurred during the enormous agricultural expansion that followed World War II. The rate of loss has slowed substantially since the 1970s, but restoration and mitigation of wetland damage continue to be slower than the rate of loss.

The recent farm bill again authorized funding for the Wetlands Reserve Program, which funds restoration of wetlands that have been converted into farmland. Unfortunately, although both the House and Senate approved $1.9 billion for this program over five years, the final bill reduced funding to $1.3 billion, reducing from 250,000 to 185,000 the number of acres that can be enrolled each year. The nation needs a stronger commitment than this.

I have not experienced the trauma of flood damage firsthand, but a quick scan of UW-Extension bulletins on flood-related problems adds to the picture painted by recent news stories. UW-Extension provides excellent information on scores of too-graphic topics, ranging from snake control after a flood to handling food contaminated by a flood, to disinfecting flood-soaked bedding. There are tips on wrapping up washing machines and other appliances in plastic before the flood to keep silt out of motors, and handling livestock sickened by flood-infected feed. Cleaning contaminants from your home. Getting water-soaked farm machinery running safely. The list of tasks, headaches and costs seems endless.

Floods are tragedies, pure and simple, and their prevention requires multiple strategies, although flooding in some places following severe storms will always occur. But one smart strategy to minimize damage is protecting wetlands. It requires more than just restoration, since even existing wetlands are often compromised by chemical contamination, invasive species and other threats. But good land use planning to minimize development on these lands, protection against contamination, and restoration of former wetlands are all sound investments in public well-being.

Margaret Krome is a Madison resident who writes this column every other week.

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