Omaha World-Herald: Scientist: Flooding unlikely to recede

Scientist: Flooding unlikely to recede

By Nancy Gaarder

RED OAK, Iowa — Scarred by more than its share of devastating floods, Iowa has undertaken an ambitious effort to prod communities and the agriculture sector to undertake sometimes costly efforts to lessen the flood threat.

The first step — understanding the worsening flood problem in Iowa — has yielded discouraging news.

“What you’ve seen in the recent past is what you are going to get,” climate scientist Chris Anderson told about 20 southwest Iowa residents and officials attending a seminar here Tuesday.

Research in Iowa has found that annual rain and snowfall have increased, heavier rains are falling more frequently, the soil is getting saturated more often and stream flows are up from 20 percent to 50 percent since the 1940s.

Adding to the problem is development in urban areas and degrading soil quality in rural areas, which are accelerating runoff.

In 2008, floods caused $8 billion to $10 billion in damage in Iowa. Damage from flooding in 2010 is still being tabulated. At Iowa State University alone, flooding caused an estimated $40 million to $50 million in damage this year.

Anderson said the wetter weather that is leading to increased flooding is due to global changes in climate.

As oceans warm, they release massive amounts of water into the atmosphere, and that fuels rain and snow. In addition to more rain and snow and higher stream flows, Iowa can also expect a rise in periods without rain, he said.

Getting people to do something about the flood risk is the purpose of a series of meetings such as Tuesday’s. Because altering development and farming practices to avoid flooding is a tough sell politically, officials have seized upon the recent past as a call to action.

Over the past two years, the Iowa Legislature has taken a number of steps to improve flood control, including sending a signal to communities that they can’t count on the state to bail them out when flooding strikes.

One community that’s set a national example for aggressive control of development is Cedar Falls, Iowa, which is now restricting development in the 500-year flood plain. Most communities restrict building in a much smaller area — land in 100-year flood plains.

Paul Assman, county engineer for Crawford County, echoed a point made by several others, which is that people have to be better educated about the risks.

“Quite frankly, that’s what causes a lot of our problems — people building where they shouldn’t be building,” he said. “People get lured into a false sense of security, but we don’t have the slightest clue about what is a 100-year flood. People are naive.”

Presenters at the seminar discussed multiple efforts under way to respond to the flood threat. Two key efforts are better flood-plain maps and more stream gauges.

The newly formed Iowa Flood Center is working on both.

Ricardo Mantilla, a research engineer and hydrologist with the center, said ultrasound river monitors can be installed at bridges for about $3,000 apiece and nominal maintenance costs.

That compares to the more elaborate ones installed by federal scientists that cost $20,000 a piece to install and $10,000 a year to maintain.

The center, a part of the University of Iowa, is piloting a program using ultrasound monitors. If they work, the network could be expanded. There are 25,000 bridges in the state, compared with only 156 federal flood gauges.

Better stream gauges are crucial, said Jeff Theulen, emergency manager for Pottawattamie County.  Incorrect flood forecasts lead to false alarms, which lead to a desensitized public. That was the case this year in Pottawattamie County, he said.

Susan Judkins Josten, director of the Rebuild Iowa Office, which was formed to assist in the state’s recovery, said the key will be learning the lessons of the last two years.

Studies done after the Great Flood of 1993 recommended the same types of preventative actions that are being recommended now.

“We’ve had nearly 20 presidentially declared disasters in the past 20 years due to flooding, so there is even more of an onus on us to take action than there was 20 years ago,” she said.

Contact the writer:



(Click here to view the original article)