Stormwater and Flooding

Stormwater and Flooding

Update: The Stormwater and Flooding ON TO 2050 strategy paper is now available and your feedback is welcome. Send your thoughts, ideas, or questions to

Flood damages are increasing

While flooding is a natural process, urban development and changing precipitation patterns due to climate change have affected the way water flows through the landscape. The Chicago region is experiencing more frequent and intense flooding events, which affect residents, businesses, and the region's economy and infrastructure. Storm and flooding events can also interrupt performance of our transportation network, leading to congestion, accidents, and road closures. In addition, property damages from reoccurring flooding have the potential to contribute to larger scale disinvestment.  

Integrating stormwater management into land use and transportation planning

Changing precipitation patterns and outdated design standards have left much of the region's infrastructure designed for yesterday's storms. The existing green and grey infrastructure designed to handle runoff is currently inadequate and requires significant investment in order to reduce negative impacts of flooding on local infrastructure, regional transportation, natural resources, and private property. The location and form of our buildings and streets can reduce stormwater runoff volumes and transform rainwater into an asset for our communities. From street designs to large-scale open space investments, land use and transportation planning can play a role in reducing flooding damages and enhancing our communities. 

ON TO 2050 will refine existing stormwater management policies

The policies in GO TO 2040 broadly covered the integration of stormwater management with development. CMAP intends to build an understanding of the region's greatest flooding mitigation needs and identify effective strategies for flood prevention and stormwater management in ON TO 2050, the next regional plan. ON TO 2050 will help communities select stormwater management approaches that align with community and regional goals of enhanced quality of life as well as environmental and economic sustainability.
As a first step in the process, CMAP reviewed the main causes and drivers of flooding in the region as well as the known impacts of flooding. This memo on the causes and impacts of flooding aims to establish a core understanding for future recommendations.