Tinley Park, IL Environmental Rules: Flood Zones (2026)

Tinley Park's floodplain ordinance implements Federal Emergency Management Agency (FEMA) National Flood Insurance Program (NFIP) requirements and MWRD WMO floodplain provisions, which are generally more stringent than NFIP minimums. Areas mapped as Zone A, AE, or AH on the FEMA FIRM are Special Flood Hazard Areas (SFHAs) subject to the 1% annual chance flood. Tinley Creek runs through the Village with mapped SFHAs in several areas. Floodplain development requires a floodplain development permit from the Village and typically WMO permit from MWRD. New residential structures in the SFHA must have their lowest floor (including basement) elevated at least 1 foot above the base flood elevation (freeboard). Substantial improvements (improvements to existing structures whose cost exceeds 50% of the structure's market value) trigger full floodplain compliance. Fill placed in the regulatory floodway is prohibited, and fill in the flood fringe requires compensatory storage (0-for-0 volume replacement). Flood insurance is federally required for properties with federally-backed mortgages in SFHAs. Homeowners outside the SFHA can still purchase Preferred Risk Policies given that flooding can occur outside mapped zones.