Elected officials: Mayor Jim Throgmorton and former Mayor Matthew Hayek
Location: Iowa City, Iowa
Iowa City (home to the University of Iowa) is a medium-sized city in eastern Iowa, just west of the Mississippi River. The Iowa River, which runs through the city, frequently overflows during heavy rain events, causing flooding. In June 2008, following record-setting tornadoes and massive amounts of rain from stalled thunderstorm systems, the Iowa River crested at about 31.5 feet (major flood stage is 25 feet). This was the city's largest flood on record, covering approximately 1,600 acres. The flood was 4 feet higher than the 100-year flood elevation, reaching roughly the mapped 500-year flood elevation. Consequently, two neighborhoods with homes that were constructed to be above the 100-year flood elevation were devastated. In total, 251 structures were damaged, and nearly 100 structures were destroyed or damaged beyond repair. More detail can be found in FEMA’s Midwest Floods of 2008 in Iowa and Wisconsin.
In response to the 2008 flood, the City Council in 2010 passed several ordinances and set up new zoning codes and policies to reduce future flood risk. The new ordinances and codes require new structures and structures that are substantially improved to be elevated or flood-proofed to 1 foot above the 500-year flood elevation. They also require structures that have people with limited mobility or emergency responsibilities to be located outside of the 500-year flood hazard area. These structures include police and fire stations, hospitals, emergency centers, senior housing and rehabilitation facilities. To address concerns about the preservation of historic properties, the city added a mechanism for a variance when elevation or flood-proofing would compromise a historic structure.
Iowa City has used voluntary property buyouts to permanently remove residents from flood hazard areas. The city was awarded funds under the Single Family New Construction Program to make up for lost tax revenue from the buyouts and provide homeownership opportunities to primarily low-moderate income homebuyers outside of the 100-year floodplain. Under this program, 141 homebuyers have received assistance purchasing newly constructed homes. According to Matthew Hayek, who served as mayor of Iowa City from 2010 to 2016, the creation of new housing elsewhere more than offset the lost revenue from property taxes due to the buyouts.
Mayors Throgmorton and Hayek discuss property buyouts
Iowa City also created the Gateway Project and the Riverfront Crossings Master Plan to make the city more resilient against flooding. The Public Works, Planning and Community Development, and Building Inspections departments all played a part in flood mitigation efforts, and in the years since the flood, the Building Inspections department and the Planning Division merged into one department to streamline and coordinate on many flood recovery programs. The city also benefited from the Iowa Flood Center (part of the University of Iowa College of Engineering), which provided expertise to improve Iowa City’s flood preparedness and resiliency. The city gained public support for its flood mitigation projects by being open in their deliberations and showing pictures of the anticipated outcomes.
Mayors Throgmorton and Hayek on how the Gateway project gained support
The Gateway Project reduces road closures of Dubuque Street and Park Road Bridge due to localized flash flood and historic Iowa River flood events. Dubuque Street is the main entrance to Iowa City and runs parallel to the Iowa River. During the 2008 flood, it was closed for an entire month. The project included raising Dubuque Street by 10 feet (which puts it at 1 foot above the 100-year flood level), and replacing and elevating the Park Road Bridge to 1 foot above the 200-year flood level. Former Mayor Hayek stresses the importance of making “the most of a flood,” by taking advantage of post-flood resources to shore up aging infrastructure with massive rebuilding.
According to the former mayor, after 2008, the city began to adopt flood protection measures that also enhance the river as an amenity for times when it is not flooding. This approach reflects a shifting attitude toward the Iowa River, viewing it as an asset or resource rather than merely a potential hazard. Under this approach, the Riverfront Crossings Master Plan was created in cooperation between the city, Environmental Protection Agency and Rebuild Iowa (a state organization). The plan aims to create a resilient riverfront park system using flood mitigation measures and stormwater best management practices. According to the EPA website, the plan would relocate vulnerable properties and infrastructure away from the floodplain and guide future development away from the most vulnerable areas. It promotes green infrastructure, vegetated buffer zones and public spaces along rivers and streams to reduce flooding, runoff and erosion.
One key piece of public infrastructure that was removed from the floodplain is the North Wastewater Treatment Plant. Wastewater is now directed to another plant approximately four miles downstream. Where the old wastewater treatment plant once stood, a park with trails and boat access is being built, and floodplain and wetland areas are being restored. This involves excavating the previously elevated floodplain to connect the restored wetland area to the groundwater table, and stabilizing Ralston Creek using stream restoration structures and vegetation. The restoration will benefit the community by providing natural riparian habitat along the Iowa River, improved water quality and flood storage during rain events.
Looking back, current Mayor Jim Throgmorton recalls that the city was taken by surprise by the 2008 flood, thinking that the ordinances put in place after the Great Flood of 1993 put the city in good shape. However, the 2008 flood proved to be much more severe. Looking toward the future, Mayor Throgmorton said Iowa City leaders anticipate future flood events will be worse than what it has experienced up to now, and the city needs to be prepared to “bounce back better than before.”
Mayors Throgmorton and Hayek offer advice to other elected officials
Take a story map guided tour through all the communities featured in Volume III's Success Stories. You can explore each communities’ timeline of flood events and responses, with an immersive narrative that includes photos, videos, and audio clips.