AUTHORS: Zach Vernon, Chicago Metropolitan Agency for Planning
ABSTRACT: Created in 2005, CMAP is the official regional planning organization for the northeastern Illinois counties of Cook, DuPage, Kane, Kendall, Lake, McHenry, and Will. The agency and its partners are in the process of developing ON TO 2050, a new comprehensive regional plan slated for adoption in October 2018. The plan will recommend a suite of actions to achieve sustainable prosperity for all of metropolitan Chicago. As part of the plan development process, CMAP has been exploring and refining policy recommendations in key areas, including strategies to address urban and riverine flooding.To help direct these recommendations, CMAP has developed a Stormwater and Flooding Strategy Paper, which will inform the related recommendations made in ON TO 2050. The paper presents strategies to reduce flooding impact throughout the region by integrating stormwater management into transportation and land use planning, alongside analysis of damages from past flooding events. To help direct these strategies, CMAP has developed urban and riverine flooding susceptibility indexes to identify priority areas across the region for flooding mitigation activities. GIS datasets representing flood susceptibility factors such as impervious cover, age of development, and combined sewers were used to construct the indexes, by assessing each factor’s influence using a GIS-based frequency ratio approach as implemented via a custom Python toolbox. The flood susceptibility indexes will help CMAP focus stormwater planning efforts within the region, and this presentation will discussion the background, inputs, analysis techniques, and results.
