Stormwater Management


Stormwater management and flood prevention in northeastern Illinois can be particularly challenging due to the region's flat topography and broad floodplains. Agricultural and urban development has not fully considered the long-term consequences of altering the region's landscape. As a result, the existing grey and green infrastructure designed to handle runoff is currently inadequate and requires significant investment in order to reduce negative impacts of flooding on private property, local infrastructure, regional transportation, an natural resources. Future development poses new challenges due to the reduction of the landscape's ability to absorb precipitation and the continuing pressure to develop flood prone areas. In addition, studies have indicated that climate change has been leading to an increase in the severity and frequency of extreme storms and that this will be particularly true in the upper Midwest, including the Chicago region.  

Stormwater crosses jurisdictional boundaries and the amount of stormwater runoff generated is heavily influenced by land use and transportation. The design of our streets and roads, which are a large contributor to stormwater runoff and are also in public ownership, can play a key role in reducing the negative impacts of future storm events. Land use and development, and the corresponding regulations, can help prevent new development and redevelopment from contributing to the problem and could potentially offer shared solutions for existing neighborhoods. Figuring out ways to better manage stormwater can also help the regional economy by reducing the stress flooding can cause on municipal budgets, the use of clean water and wastewater treatment costs, and private property damage and loss.

Integrating better stormwater management decisions into local planning, municipal operations and budgeting decisions, data and information sharing, and transportation planning and programming will be essential to tackling this problem. GO TO 2040 calls for integrating land use policies and site planning with water resources and identifies compact development, redevelopment, water conservation, and green infrastructure as essential techniques. The plan reinforces the need to not just rely on stormwater detention, but also to reduce the volume of runoff and use green infrastructure to manage stormwater. The plan also recognizes the need to develop sustainable sources of financing for stormwater retrofits and to provide performance data to stormwater managers. CMAP is currently engaged in the following activities related to stormwater management:

Stormwater Management Opportunity Planning

Urban flooding is a common concern among the region's municipalities, yet many lack the resources to identify opportunities and strategies to address flooding issues. CMAP has developed an approach to help identify problem areas and begin to articulate discrete, on-the-ground opportunities for improvements that can reduce flooding. CMAP is incorporating this approach in local planning projects though the Local Technical Assistance (LTA) Program.

Calumet Stormwater Collective

CMAP is an active member of the Calumet Stormwater Collaborative, which was formed in 2014 to improve stormwater management through investments in and coordination of green infrastructure solutions.

Stormwater Utilities

Storm sewers, culverts, and a host of other stormwater infrastructure components need repair, but funding for capital improvements is scarce. CMAP has outlined the legal authority and key components of a establishing a stormwater utility to respond to these challenges. 

Stormwater Planning Data Inventory

The Stormwater Planning Data Inventory includes a list of datasets that can inform local and regional analyses of flooding issues.