TRANSMITTAL LETTER FOR BOARD MEETING OF NOVEMBER 2, 2017
COMMITTEE ON STORMWATER MANAGEMENT
Mr. David St. Pierre, Executive Director
Title
Report on Green Infrastructure, Detention, and Compensatory Storage Volumes Required by the Watershed Management Ordinance
Body
Dear Sir:
The Watershed Management Ordinance (WMO) regulates sewer construction within the District’s service area and development within suburban Cook County. It provides uniform stormwater management regulations to prevent future development projects from exacerbating flooding and protect environmentally sensitive areas. Green infrastructure (GI) is installed to comply with the stormwater management requirement of capturing one inch of stormwater runoff from all impervious surfaces of the development. Detention requirements have been enhanced by the WMO as compared to the previous requirements under the Sewer Permit Ordinance, and compensatory storage is required to mitigate development impacting the floodplain.
When a WMO permit is required, the development must comply with the stormwater management provisions of the WMO. The attached table includes the number of permits issued per quarter since the WMO became effective. It also summarizes the development area, volume captured by GI, locally-provided detention, and compensatory storage. The total for each year and running total are also provided. This table will continue to be updated at the end of each quarter and transmitted for your information.
Respectfully Submitted, Marcella V. Landis, Acting Director of Engineering, WSS:JK
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