Page 93 - Mapping the Nation: Taking Climate Action

"We get a lot more rain than when I was a kid," said Nikki Rosemeyer, GIS coordinator and analyst for the City of Dubuque. "We had six inches of rain in one storm this summer. If we get an inch and a half of rain, you see a river two feet deep flowing through the streets of our downtown." Bee Branch Background As Dubuque expanded to higher ground away from the Mississippi River, the problem worsened. Recurring property damage from frequent flooding prevented homeowners from accruing equity. During the five years from 2005 to 2009 when the assessed value of commercial property in Dubuque increased by 39 percent, it decreased by 6 percent in the flood-prone area. Initially, the floods affected only basements, but with growing development and climate change, the magnitude and frequency of flooding increased. Dubuque has a series of limestone bluffs above its low- lying downtown. Rosemeyer imported lidar data into GIS to visualize the city in 3D and identify the drainage basin causing stormwater runoff problems. problem, but that doesn't help the folks in the homes that have been getting flooded for the last 50 years," said Sharon Gaul, former grants project manager for the city's housing and community development department. "We decided to address both the public infrastructure and the housing structure." The Iowa Economic Development Authority received a $96 million Community Development Block Grant through the National Disaster Resilience Competition funded by the US Department of Housing and Urban Development and Rockefeller Foundation. Dubuque was one of nine watersheds to receive Iowa Watershed Approach funds, with $23.1 million for infrastructure improvements and $8.4 million for housing improvements. The city planned to complete 275 housing unit restorations and three major stormwater improvements by June 2021 for the multiphase work of the Bee Branch Watershed Flood Mitigation Project and the Bee Branch Healthy Homes Project. The flood mitigation project had been ongoing since 2003, and the homes project started in 2016. "There are a few different funnels that force a lot of water at a very high rate of speed through residential streets," Rosemeyer said. Six presidential disaster declarations were made between 1999 and 2011 when repeated flooding caused an estimated $70 million in damages to public and private property. Ensuring Healthy Homes The city applied for grants to mitigate the severe and frequent flash flooding. "We spent probably 15 years trying to put funding together for the stormwater A storytelling map of the Bee Branch Healthy Homes project details the actions taken to mitigate each address. 92 Inland Flooding