Schaumburg, IL Environmental Rules: Stormwater Management (2026)

13, 'Storm Sewer and Drainage Systems,' bars village approval of any residential, commercial or industrial subdivision unless it is served by storm sewers kept separate and independent of the sanitary sewer system, with an adequate outlet to an existing storm sewer network, consistent with the Cook County Watershed Management Ordinance (WMO). Design standards under subsection (B) require engineers to size storm sewers by the rational method on a 10-year storm frequency, using rainfall intensity data from Illinois State Water Survey Bulletin 70, and to route the runoff from a 100-year storm safely overland to the detention basin in case underground pipes clog.

Street and parking-lot drainage may not pond surface water more than six inches deep or send it across an intersection, and building sump pumps must connect to an available storm sewer with four-inch or larger rigid PVC pipe. Subsection (B)(13) requires retention-detention facilities for every nonresidential development larger than two acres, sized and released at the same volume and rate the WMO sets, with a minimum three-inch restrictor opening unless the village engineer approves a smaller one. Detention basins without a permanent pool must be landscaped with native plantings on slopes no steeper than four-to-one, and basins with a permanent water level need an eight-to-one safety shelf six feet wide, two feet below normal water level, to control erosion and support habitat.

The village engineer of community development reviews and approves every grading and drainage plan before a land development permit issues, and can require design revisions if erosion, flooding or capacity problems appear during construction.