The RainReady Approach: Linking Municipalities and Residents to Manage Urban Flooding with Distributed Green and Grey Infrastructure
This paper presents approaches to residential flood mitigation through the RainReady program, developed by the non-profit Center for Neighborhood Technology. Urban flood mitigation programs may be designed in a number of ways, as illustrated by two case studies that each offer unique outcomes for flood risk analysis and reduction; community participation; and distributed stormwater infrastructure design.
“Urban flooding” as described here, occurs when precipitation overwhelms local drainage systems, and is most often predicated by undersized or failing sewage infrastructure, along with impermeable surfaces predominant in urban areas that do not allow for stormwater infiltration. Unlike riverine and coastal flooding, urban flooding can be highly localized - where even one building floods and an adjacent building does not due to individual site characteristics.
Two case studies are provided to illustrate assistance programs for localized flooding, that differ in approach to community outreach and financing.
Case Study 1 - City of Chicago, Illinois Residential Flood Assistance Program: After a 10-year storm inundated Cook County, Illinois in 2013, RainReady partnered with the Chicago Department of Planning and Development to provide free repairs and flood mitigation retrofits to select homeowners that experienced property damage, through their Residential Flood Assistance Program (RFAP). The program was funded through The U.S. Department of Housing and Urban Development’s Community Development Block Grants for Disaster Recovery (CDBG-DR). Recommended work typically included both green infrastructure and conventional flood mitigation measures. Backflow prevention valves were one of the most commonly installed mitigation measures. Other measures included foundation drains, sump systems, gutter and downspout repair, and site grading.
Case Study 2 - The Village of Oak Park, Illinois Pilot Program: In 2016-2017, RainReady partnered with the Village of Oak Park to launch a pilot program to reduce urban flooding risks using nature-based solutions such as residential rain gardens. The program addressed residential flooding due to overland sheet flow, seepage, and yard ponding, in non-floodplain locations. Ultimately, all grant-eligible measures were required to enhance onsite stormwater infiltration, such as through rain gardens, dry wells, and permeable pavement. Approximately 70 percent of program participants proceeded with construction of green infrastructure, predominantly rain gardens connected to disconnected downspouts and swales.
According to RainReady protocols, and demonstrated in these case studies, flood programs should:
- integrate resident knowledge into the risk assessment process;
- prioritize resident goals in the mitigation scope;
- weigh program requirements against participation goals; and
- incentivize measures that provide community-wide resilience benefits.
The studies have found that community flood resilience often can be best supported by utilizing distributed infrastructure with site-level building retrofits that include both grey and green infrastructure solutions. Community engagement and homeowner education is also integral to success by encouraging disaster preparedness and home maintenance activities that can reduce the impact of urban flooding - and in turn reduce the burden on the municipality in the long run.
Publication Date: 2017
Authors or Affiliated Users:
- Marcella Bondie Keenan
- Anna Wolf
- Center for Neighborhood Technology
- Best practice
- Case study