The Illinois Department of Natural Resources, in collaboration with Illinois State Water Survey, developed a model stormwater ordinance to help Illinois communities manage flooding and combat flooding-related damages in urban areas. The ordinance was developed as a result of a report that found increasing extreme precipitation events and that an increasing number of flood claims are occurring outside of floodplains.
The model stormwater ordinance includes specific recommendations and regulations to better mitigate urban flooding damages:
1. Incorporate green infrastructure into development regulations by recommending non-structural best management practices treat at least 25% of water quality requirements and volume controls;
2. Incorporate water quality controls wherever possible to protect the hydrology, hydraulics and beneficial functions of streams, lakes, wetlands, floodplains, and flood-prone areas;
3. Provide incentives to developers and property owners to decrease impervious areas and preserve natural areas to allow for evaporation/transpiration, infiltration, and stormwater storage;
4. Limit stormwater runoff from development sites to prevent flooding and excessive erosion;
5. Establish maintenance plans to ensure stormwater measures remain as originally intended.”
The idea is that counties and municipalities will look to the model ordinance as a resource when drafting or revising their own stormwater runoff requirements. Local governments should find this model ordinance helpful in supplementing their existing codes. Each local jurisdiction should review the components and tailor their ordinances in accordance with local conditions and development activities.
Hopefully, implementation of these ideas will minimize or prevent entirely damage that result from extreme weather events and flooding.