Flooding in urban areas from stormwater runoff may be mitigated when state and local governments plan a coordinated effort to reduce their risk. The Illinois State Water Survey (ISWS) and the Illinois Department of Natural Resources (IDNR) offered their support to communities by developing a model ordinance that city and county officials can use when revising or drafting their own stormwater ordinances.

Model Stormwater Management
Ordinance (IDNR)

The model ordinance is a template containing the minimum requirements for an effective ordinance and best practices for maximum stormwater protection, according to Sally McConkey, head of the Coordinated Hazard Assessment and Mapping Program at the ISWS, Prairie Research Institute, University of Illinois. It is intended to be used as a stand-alone document to assist any community wishing to revise its ordinance requirements for stormwater management, or it could be used as a guide to add stormwater provisions to existing subdivision ordinances, building codes, or zoning ordinances.

“The stormwater model ordinance is one tool a community can use to manage stormwater and reduce flood damages,” McConkey said.  “Adopting provisions of the ordinance can also earn Community Rating System points for participating communities which can lower flood insurance rates.”

In the past century, nearly all flood claims involving private and federal flood insurance were located in urban areas, and about 90 percent of those claims were located outside of floodplains, according to the Report for the Illinois Urban Flooding Awareness Act. (http://www.isws.illinois.edu/hilites/more.asp?id=ufaa&fr=hi).  With extreme precipitation events increasing by as much as 40 percent, local ordinances will become particularly important in the future as communities mitigate stormwater runoff damage to new development and redevelopment.

The ISWS and IDNR encourage communities to adopt strategies provided in the ordinance as best practices to mitigate flooding from stormwater runoff.  One strategy is to provide incentives to developers and property owners to decrease impervious areas and preserve natural areas to allow for evaporation, infiltration, and stormwater storage.

The model ordinance is now available for local officials at

http://www.dnr.illinois.gov/WaterResources/Documents/IL_Model_Stormwater_Ordinance.pdf