Skip to main content

Metropolitan Water Reclamation District of Greater Chicago

It was 10 years ago this month that a Metropolitan Water Reclamation District of Greater Chicago (MWRD) landmark policy went into effect.

Following years of development, public comment, analysis and adoption, the MWRD’s Watershed Management Ordinance (WMO) was formally introduced in May 2014. Today, as it was intended, the WMO works to protect public health, safety, and welfare and Cook County homes and businesses from flood damage by managing and mitigating the effects of development and redevelopment on stormwater drainage. 

Watershed Management Ordinance development
Developments greater than 0.5 acre must comply with the stormwater management provisions of the MWRD’s Watershed Management Ordinance to prevent development from exacerbating flooding.

Over the last decade, through the WMO, more than 154 million gallons of rainwater have been retained in green infrastructure volume control practices. In addition, more than 3,100 permits have been issued for more than 9,100 acres of development to create nearly 70 million gallons of compensatory storage and detain more than 700 million gallons of stormwater runoff. As a result of the WMO, the MWRD developed watershed specific release rates to ensure detention facilities are sized appropriately and incorporated a regional stormwater detention and volume control trading program.

“We are proud of the 10 years of achievements, stormwater capture and protection for our environment since our Watershed Management Ordinance went into effect,” said MWRD President Kari K. Steele. “If communities grow without careful and thorough stormwater planning, sewer systems and local waterways can become overwhelmed. It is because of prudent planning and policies like the WMO that we are building livable, thriving communities throughout Cook County.”

Where the WMO is applicable

The WMO provides uniform minimum stormwater management regulations for Cook County and prevents proposed com­mercial, municipal, and residential development and redevelopment projects from exacerbating flooding. It applies to all development outside of the City of Chicago within the boundaries of Cook County.  It also regulates qualified sewer construction within the MWRD’s corporate boundaries, outside of the City of Chicago, as well as in service agreement areas.  The WMO regulates qualified sewer construction, drainage and detention, volume control, floodplain management, isolated wetland protection, riparian environment impacts, and soil erosion and sediment control. The WMO accomplishes this by requiring site runoff detention facilities, compensatory storage and/or green infrastructure installations to control the rate at which water is released in developed conditions. Any development greater than 0.5 acre must comply with the stormwater management provisions of the WMO.

Historical Timeline

The challenges the WMO seeks to address have been centuries in the making. A flat topography and low permeable soil contributed to poor drainage in the Chicago region. A surge in population during the 19th and 20th centuries resulted in more development, paved roads, parking lots, walkways and buildings leaving less permeable space to absorb water. The  MWRD’s Sewer Permit Ordinance was implemented in 1969 to provide regulation, permitting and enforcement for qualified sewer construction. In 2004, the Illinois General Assembly granted the MWRD regional stormwater management authority for Cook County which allowed the MWRD to prescribe by ordinance reasonable rules and regulations for flood plain and stormwater management and for governing the location, width, course, and release rate of all stormwater runoff channels, streams, and basins in Cook County. Planning for the WMO was initiated in 2004 when the MWRD established a 33-member advisory committee. Members represented government agencies, non-governmental organizations and at least two members of each of the watershed planning councils from the six watersheds that the MWRD serves.

“It is because of the Watershed Management Ordinance that communities know their development and redevelopment will incorporate features to manage stormwater on a flat terrain impacted by the effects of climate change,” said MWRD Commissioner Yumeka Brown. “The WMO is one of the most important policies we have today working to reduce or mitigate the environmentally detrimental effects of future runoff.”

Learn more

Press Release

Established in 1889, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) is an award-winning, special purpose government agency responsible for wastewater treatment and stormwater management in Cook County, Illinois.


For more information: