Among the current projects at the Iowa Flood Center (IFC) are two efforts to develop floodplain maps, and a project to place stream-stage sensors on bridges across the state.

Web-Based Flood Inundation Maps

Web-based flood inundation map for Des Moines, Iowa

IFC researchers are developing high-resolution web-based flood inundation maps for several communities in Iowa. With data gathered through bathymetric surveys to determine the shape of the channel, supplemented by aerial LiDAR data, researchers can create very detailed maps of the streambed, which can be used to illustrate the extent of flooding under different flooding conditions.

The information is available to the public via an interactive Google Maps-based online application, so community members can see how predicted flood levels could affect their property. Maps for several Iowa communities are already available at the Iowa Flood Center website.

The Iowa Floodplain Mapping Project

Building on the success of the flood inundation maps, IFC researchers have begun work on a project that will provide less-detailed floodplain maps for most of Iowa. The four-year Iowa Floodplain Mapping project is funded with $10 million from the U.S. Department of Housing and Urban Development. Working closely with the Iowa Department of Natural Resources (DNR), the IFC will develop FEMA-approved floodplain maps for the 85 Iowa counties that were declared federal disaster areas after the 2008 floods.

“These maps will provide Iowans with new information concerning flood risk in their own communities, so they are empowered to make informed land use and land management decisions,” says Nathan Young, IFC associate director and an IIHR associate research engineer.

IFC researchers will map all streams draining one square mile or more in each of the 85 Iowa counties, relying on statewide LiDAR (laser radar) data recently collected by the DNR. LiDAR is a remote sensing technology used to develop digital elevation models of the land surface. Young says this will make it possible to accurately describe Iowa’s river and stream networks, develop computer-based flood simulations, and delineate floodplains. In the process, researchers hope to develop innovative, efficient new floodplain mapping tools.

Once completed, the maps will be available online to guide floodplain regulation and management.

Affordable Stream Stage Monitoring

The sensor uses sonar to measure the distance to the water.

Until recently, gauges to measure river and stream levels were few and far between in Iowa. IFC students helped develop an affordable electronic sensor to measure stream levels and transmit up-to-the-minute data to the center. The sensor is placed on bridges and uses sonar to measure the distance from the water’s surface to the sensor. This information, transmitted via cell phone to a central database, provides an accurate picture of current stream levels.

The DNR and the IFC recently completed a pilot project to deploy a preliminary network of 50 sensors across the state. Fifty more sensors were deployed in 2011, and more are planned for 2012. A statewide system that could be in place within a few years would enhance the ability to monitor stream stages and predict flooding.

Renewed state funding in 2010 and other grants allow the IFC to continue advancing our understanding of floods. In November 2010, for example, new funding from the U.S. Department of Housing and Urban Development was announced, to support pilot projects to help Iowa minimize erosion, manage runoff, and mitigate future flood damage. This project, and others to come, will help ensure that Iowa is better prepared to handle inevitable future flooding.

To learn more about these projects and others at the IFC, visit the Iowa Flood Center website.