For years, stormwater management in Cook County was a patchwork of efforts by local, regional, state and federal agencies. Then in November 2004, the Illinois General Assembly enacted Public Act 93-1049, allowing for the creation of a comprehensive stormwater management program in Cook County under the supervision of the Metropolitan Water Reclamation District of Greater Chicago (MWRD). The Act required the MWRD to develop the Cook County Stormwater Management Plan (CCSMP), which provides the framework for the stormwater management program. This includes the program’s mission, purpose, goals, assessments and plans. The MWRD’s Board of Commissioners adopted the plan in February 2007.

With the adoption of the CCSMP and the implementation of the MWRD’s countywide stormwater management program, Cook County has the means to address a range of stormwater management issues through proper watershed regulations and watershed planning. Under this plan, the MWRD established Watershed Planning Councils and completed Detailed Watershed Plans for the six major watersheds in Cook County; initiated a Stormwater Management Capital Improvement Program; initiated a Small Streams Maintenance Program; and adopted and implemented the Watershed Management Ordinance (WMO).

The CCSMP was amended in July of 2014 to be consistent with P.A. 98-0652, which grants the MWRD authority to acquire flood-prone properties and to plan, implement, finance and operate local stormwater management projects. The MWRD entered into a Consent Decree with the Environmental Protection Agency in January 2014, which prompted establishment of the Green Infrastructure Program. Additionally, the Infiltration/Inflow Control Program was incorporated into the WMO in 2014.