Skip to main content

News & Updates

Chicago’s New Stormwater Law Effective January 1, 2008


January 1, 2008

Read Time

3 minutes


Chicago’s antiquated combined sewer system, first built in 1856, captures raw sewage and stormwater together before sending it downstream away from the city. Due to a technicality in the Clean Water Act regarding discharges into combined sewer systems, most Chicago developers have avoided onerous federal stormwater requirements. Meanwhile, despite spending billions on the Deep Tunnel, $50 million per year to upgrade sewers, and additional funds for rainblockers on city streets, the sewer system is overburdened. During heavy rains, the Metropolitan Water Reclamation District routinely discharges overflow sewage into the Chicago River and occasionally into Lake Michigan.

Chicago’s new Stormwater Management ordinance, effective January 1, 2008, is directed towards solving the sewage overflow problem. Though the ordinance does not regulate detached single or two-family homes, it applies to all other new developments and redevelopments which either (a) disturb more than 15,000 square feet, (b) create an impervious surface of 7,500 square feet or more, or (c) directly discharge stormwater into any water body or separate (rather than combined) sewer system.

Developers are most concerned that many new projects must capture and retain the first one-half inch of rain during any storm. Below is a summary of the ordinance.

Before any construction begins after January 1, 2008, each regulated project must have a Stormwater Plan approved by City officials. The Plan, which imposes an application fee ranging from $1,000 to $3,000, must provide the following:

  • Site Plan – Developers must submit a detailed site plan, including building structures and fences, roadways, pervious areas including grass and dirt, surface flow and grading directions, proposed sewers, and the location of building outspouts;
  • Volume Control – Documentation must establish that the development will capture one-half inch of run-off from all impervious surfaces, or for developments not directly discharging into waters or a separate sewer system, a fifteen percent reduction in impervious surfaces from existing conditions. To achieve these mandates, the City has issued regulations outlining “Best Management Practices” (BMPs), which, if properly installed, utilized and maintained, are acceptable for meeting the volume control requirements. BMPs include installation of bio-infiltration systems (rain gardens), drainage swales, green roofs, natural landscaping, permeable paving, rooftop runoff BMPs (planter boxes, rain barrels and cisterns), stormwater trees and vegetated filter strips.
  • Discharge Rate Control – The development must manage the rate of off-site discharge. Among other requirements, developments must be designed to manage the 100-year storm event and to provide means to manage and direct overflows to the public right-of-way. BMPs for meeting these requirements include restrictors, detention basins, detention vaults, oversized pipes, and parking lot and roof detention.
  • Sediment/Erosion, Operation/Maintenance and Other Controls – The plan must provide adequate measures to curtail erosion and continue to meet the requirements throughout the project’s existence. Specific types of construction projects must also include measures such as catch basins, intercepting grease basins and lint and trench basins.

Though the Ordinance allows variances, they are discouraged and may only be issued if the applicant demonstrates exceptional circumstances.

Both the City Departments of Water Management and the Environment are authorized to enforce the new stormwater law. Failure to obtain Plan approval prior to construction subjects the violator to a civil penalty of $5,000 to $10,000. Penalties for other infractions range from $100 to $1000 each day, as well as attorney fees and up to three times the City’s expenses in remediating a violation. The City also has authority to issue cease and desist orders to shut projects down for failure to meet the requirements of the new law.


June 29, 2022

City of Chicago Adopts New “Cooling Ordinance”: What Do Chicago Community Associations Need to Know?

Read More

June 29, 2022

Reminder to Chicago Employers: New Sexual Harassment Policy, Notice, and Training Requirements Take Effect July 1

Read More