Since the inception of the Stormwater Management Program in 2014, MWRD has been assisting local communities to plan, implement, and finance stormwater projects. In December 2014, five planning pilot studies were initiated for the following areas:

• Little Calumet River/Cal-Sag Channel Drainage Areas
• Northbrook and Unincorporated Northfield Township
• Roberts Road Drainage Area
• Village of Harwood Heights
• City of Chicago’s 8th Ward and Surrounding Area

Upon the completion of these studies in 2017, a standardized approach, incorporating lessons learned from these studies, was developed for conducting additional planning studies.

Subsequently, six study areas were identified and prioritized in 2019. The scope of these studies included comprehensive analysis of existing flooding issues, development of concept-level alternative solutions, and review of potential funding opportunities for implementing stormwater improvements. These studies, completed in 2022, provided meaningful recommendations for reducing the impact of flooding issues in the following priority study areas:

• Butterfield Creek
• North Creek and Deer Creek
• Weller Creek and Willow Creek
• South Suburbs
• Chicago West
• Chicago South

Realizing that expanding this traditional approach for planning countywide could take several decades, MWRD has developed a new volume-based approach to expedite planning, prioritize, and track stormwater project implementation.

A New Approach

Stormwater plans developed through a traditional approach often have a limited shelf-life due to changing conditions such as climate, development, and community priorities. This traditional approach can result in static solutions unable to meet the dynamic needs of an ever-changing future.

To develop a long-term vision for stormwater planning that is flexible and dynamic, MWRD has developed an innovative approach that is more compatible with each community’s needs and timeline for addressing their stormwater issues. MWRD recognized that the core principle of its Watershed Management Ordinance (WMO)—ensuring volume control and/or detention is created for new development to abate the negative impacts of stormwater runoff—could serve as a useful planning tool applicable across the entire county. By adopting this WMO principle, an estimate of volume needed throughout subwatersheds and sewersheds across the county can be established, serving as the foundation of a planning tool that places each community’s stormwater needs on common ground.

Volumetric Planning Portal

This Volumetric Approach will provide a set of dynamic tools that can be used to identify potential flooding issues across the county and develop mitigation strategies in a significantly shorter timeframe. It includes building an online platform to allow communities and other agencies to easily access information from a Geographic Information System (GIS) database. The GIS data will be continuously updated in response to climate change and evolving development trends, ensuring that the data remain relevant and compatible with each community’s changing priorities and timelines.

Initially, this approach will allow MWRD to answer two crucial questions about urban flooding: Where is it most likely to occur, and what is magnitude of the issue? The development of this tool encompasses a series of countywide maps and data metrics being created to identify where potential flood-prone areas, opportunities for mitigation projects, and priority areas for actionable next steps.

Future Vision

The Volumetric Approach for Stormwater Planning is anticipated to achieve more impactful results in a significantly shorter timeframe compared to traditional planning approaches. Leveraging the foundation of the GIS data, additional tools could be integrated in the future to further streamline planning processes and reduce investment in planning studies by facilitating conceptualization and implementation of projects. Examples of additional data that could be incorporated to enhance the tool's effectiveness include local storm and combined sewer conveyance information, flooding data gathered from past studies, and the location of planned infrastructure projects, along with other pertinent community data that align with the goals and objectives of MWRD’s Stormwater Management Program.

The data and web tools for the Planning Portal are currently undergoing data quality reviews and testing. The portal is anticipated to be publicly released in early 2024.