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Naperville, IL Environmental Rules: Flood Zones (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

FEMA flood zone rules in Naperville, IL, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.

Key Facts

DuPage area rule: DuPage Countywide Stormwater/Floodplain Ordinance
Will County area rule: Will County Stormwater Management Ordinance
DuPage ordinance effective: May 14, 2019
Copy on file: City Engineer's office

FEMA Flood Zone Lookup

FEMA assigns every parcel in the U.S. a flood-hazard designation on its Flood Insurance Rate Maps (FIRMs). Zones starting with A or V are high-risk Special Flood Hazard Areas where federally backed mortgages require NFIP flood insurance. Zone X indicates moderate-to-minimal risk, where insurance is optional but often recommended. Your specific zone determines insurance cost, build elevation, and permit requirements in Naperville, IL.

Zone	What it means	NFIP required?
A	High-risk flood area; 1% annual chance flood, no detailed analysis.	Yes
AE	High-risk; same as A but with established Base Flood Elevations.	Yes
AH	High-risk shallow flooding (1-3 ft), usually ponding.	Yes
AO	High-risk shallow flooding (1-3 ft) with sheet flow on sloping terrain.	Yes
V	High-risk coastal zone subject to wave action (no BFE).	Yes
VE	High-risk coastal zone with wave action and established BFEs.	Yes
X (shaded)	Moderate risk; between the 1% and 0.2% annual chance flood.	Recommended
X	Minimal risk; outside the 0.2% annual chance floodplain.	No

Look up Naperville, IL on the FEMA flood map

FEMA maps update periodically; verify zone before buying flood insurance or building.

Summary

Naperville doesn't write its own floodplain code - City Code § 5-6-1 adopts the DuPage Countywide Stormwater and Floodplain Ordinance by reference for the city's DuPage County area, with a separate Will County ordinance covering the rest.

The flood plain regulations for development in special flood hazard areas in the DuPage County portion of the City as contained in the DuPage Countywide Stormwater and Floodplain Ordinance, effective May 14, 2019, as amended from time to time, are hereby adopted by reference. One (1) copy of said regulations, effective August 1, 2019, shall be kept on file for public inspection in the office of the City Engineer.
(Ord. 99-103, 6-15-1999; Ord. No. 12-094, § 3, 7-17-2012; Ord. No. 13-059, § 3, 6-18-2013; Ord. No. 19-083, § 2, 6-18-2019)

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 101).

Full Breakdown

Naperville's own code contains no free-standing floodplain rulebook; instead § 5-6-1 adopts by reference the DuPage Countywide Stormwater and Floodplain Ordinance (effective May 14, 2019) for development in special flood hazard areas within the DuPage County portion of the city, with a copy on file with the City Engineer. A parallel provision, § 5-6A-1, adopts the Will County Stormwater Management Ordinance (effective November 28, 2018) for the smaller Will County portion of Naperville. Which county ordinance governs a given parcel depends on which county it sits in.

Violations & Fines

Developing in a mapped flood hazard area without following the adopted county ordinance is a code violation enforced through the City Engineer's office; the specific permit and penalty terms are set out in the adopted DuPage or Will County ordinance itself, on file at City Hall.

Frequently Asked Questions

Does Naperville have its own floodplain ordinance?

No. City Code § 5-6-1 adopts the DuPage Countywide Stormwater and Floodplain Ordinance by reference for flood hazard development in the DuPage County part of the city.

What governs floodplain rules in the Will County part of Naperville?

§ 5-6A-1 adopts the Will County Stormwater Management Ordinance, effective November 28, 2018, by reference for that portion of the city.

Sources & Official References

[1]Naperville Municipal Code § 5-6-1

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