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Chris Anderson, from Iowa State University's Climate Science Initiative, said rainfall amounts in the Midwest have increased 31 percent, and heavy rainfall events occur more frequently now than in the previous 100 years.

"It's not just something that's going on in Ames; it's something that the scientific community has found across the whole northern United States is changing," Anderson told the approximately 50 attendees, most of whom were Iowa city or county officials.

Land use change also needs to be considered, said Kristie Franz, assistant professor of Geological and Atmospheric Sciences at ISU.

"Because climate is not explaining everything that's going on in our watersheds," she said.

The Cedar Falls City Council amended its ordinances after a landowner requested to build in the 500-year flood plain just four weeks after the floodwaters receded in 2008. The council's policies now prohibit new subdivisions within the flood plain, Councilman Kamyar Enshayan said.

"Nearly every city has filled in its flood plain, and that's not good," Enshayan said. "That has to change." When developers build in the flood plain, "that water has to go somewhere."

Jason Conn, a flood plain planner for the Iowa Department of Natural Resources, said the agency is in the process of updating county flood plain maps and addressing flood plain permitting.

"We don't want to allow new development in the flood plain that will adversely affect existing development," Conn said.

Allen Bonini, a watershed improvement program supervisor for the DNR, said water quality improvements that settle sediments and nutrients and kill bacteria can also help mitigate flooding.

"Let flood plains act like flood plains," Bonini said.

Legislative recommendations from the Rebuild Iowa Advisory Commission to support disaster recovery and preparedness have gone largely unimplemented due to budget constraints, said Aaron Todd, a community planning specialist for the commission.

Enshayan said cities and counties can play an important role in mitigating flood effects.

"Cities do have an important responsibility," he said. "We think of it as individuals … but when we really think about it, it's the cities and counties that are shaping the future."

Ricardo Mantilla, a research engineer for the Iowa Flood Center, said the organization is developing tools to assist local governments.

New technology is helping explain how rainfall from storms turned into runoff in 2008 and channeled downstream until it formed a "massive flood wave" for Cedar Rapids and other communities.

The Iowa Flood Center is improving flood monitoring and forecasting, and creating detailed computerized maps that demonstrate how deep and fast water will flow at specific locations. The maps should be available statewide within about five years, Mantilla said.

"There is a big gap between the research community and what's being communicated" to communities, he said.

The seminar was hosted by Iowa's Rebuild Iowa Office in cooperation with University of Iowa's Center for Global and Regional Environmental Research, University of Northern Iowa's Center for Energy and Environmental Education, Iowa State University Extension, Iowa League of Cities, Iowa State Association for Counties, the Department of Natural Resources and Department of Agriculture and Land Stewardship.

He joined other state and local officials this past week for a seminar, "Anatomy of Iowa Floods: Preparing for the Future," at North Iowa Area Community College.

Panelists discussed flood plain management strategies, water quality issues, building rural-urban watershed coalitions, state and public policy issues, and increasing precipitation and water run-off in Iowa.

Cedar Falls Councilman Frank Darrah discussed his city's re-written flood plain ordinance, which includes no new development in what's now called a 500-year flood plain.

Charles City Mayor Jim Erb said he'd like an alliance of urban and rural interests.

"I don't think without both we'll be successful in making much progress," he said. "We clearly have been very successful in draining the land, but in doing that we're taking a lot of water and accelerating how quickly it goes into the river, so therefore you get higher levels quicker.

"I'm all in favor of a regulatory approach to flood plain issues," Erb said. "I congratulate them on putting together the program, and I hope we're able to pursue a positive plan for the entire watershed."

Increased water retention and infiltration would reduce pollution and flood damage, said Bill Ehm, water policy coordinator for the Iowa Department of Natural Resources.

"Let the flood plain be a flood plain," he said. "Keep it undeveloped."

Hogg noted that disaster mitigation was funded this year through the I-JOBS initiative, and legislation has passed to mitigate future flood damage.

He said all communities should be involved in the National Flood Insurance Program, and suggested paying landowners who help in floodwater prevention, and improvements such as rain gardens.

"We need to change," Hogg said. "We need to organize."

The seminar was hosted by the University of Iowa's Center for Global & Regional Environmental Research, the Rebuild Iowa office, the University of Northern Iowa Center for Energy and Environmental Education, Iowa Department of Natural Resources, Iowa Department of Agriculture and Land Stewardship, Iowa State University Extension, Iowa League of Cities, and the Iowa State Association of Counties.

Did You Know?

• Annual rainfall plus snowfall in Iowa has increased by 19 percent since the 1870s.
• Rainfall increase has been largest in spring and early summer, except in southeast Iowa, where fall rains have increased.
• Days with rainfall in excess of 1.25 inches have been more frequent.
• Stream and river flow have increased by 20 percent in the past 20 years.
• Spring soil moisture has been near saturation more frequently.
• Rainfall in the next 10 to 15 years will be like the past 20 years.
• Drought frequency in the next 10 to 20 years will be more like the 1950s to 1980s than the 1990s to the present.
• A wider variation between rainfall extremes will emerge in the next 30 years and beyond.

— Iowa State University Climate Science Program (http://climate.engineering.iastate.edu).