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Cook County, IL Environmental Rules: Flood Elevation Requirements (2026)

Some Restrictions

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

Key Facts

Freeboard requirement: 2 feet above base flood elevation
Governing chapter: Cook County Code Chapter 106
Applies in: Unincorporated Cook County only
Enforcing agency: Dept. of Building and Zoning
Penalty: $50 to $1,000 per day

Summary

In unincorporated Cook County, new and substantially improved buildings in flood zones must set the lowest floor at or above the flood protection elevation: base flood elevation plus two feet of freeboard.

City-specific rules exist: Evanston, Tinley Park, Oak Lawn, Chicago, Schaumburg, and Arlington Heights have their own flood elevation requirements rules that differ from Cook County's county-level regulations. If you live in one of those cities, check the city-specific page instead.

Flood Protection Elevation (FPE) means the elevation of the Base Flood (or depth) plus two feet of Freeboard at any given location in the Floodplain.

View official code

Full Breakdown

Cook County Code Chapter 106 sets the county's floodplain construction standard for unincorporated territory. Section 106-9(3) requires new buildings, substantial improvements, and manufactured-home or travel-trailer installations in a special flood hazard area to have their lowest floor, including any basement, built at or above the flood protection elevation (FPE): defined in Section 106-2 as the base flood elevation plus two feet of freeboard. The Department of Building and Zoning reviews elevation certificates and site plans before issuing a floodplain development permit, whether the building is elevated on fill, on piers or columns, or dry-floodproofed as a nonresidential structure.

Violations & Fines

Building below the required elevation without a permit draws a fine of $50 to $1,000 per day the violation continues, a stop-work order, and possible suspension of NFIP flood insurance coverage under Section 106-13.

Frequently Asked Questions

Does this freeboard rule apply in Chicago or Cook County suburbs?

No. Cook County's floodplain jurisdiction under Chapter 106 covers only unincorporated county territory; incorporated cities and villages, including Chicago, administer their own floodplain ordinances.

What exactly is the flood protection elevation (FPE)?

The base flood, or 100-year, elevation plus two feet of freeboard, per Cook County Code Section 106-2: the minimum height required for a building's lowest floor in a flood hazard area.

Can a building be floodproofed instead of elevated?

Only nonresidential buildings may be dry-floodproofed to the FPE instead of physically elevated, per Section 106-9(3)(c), and the design must be certified by an Illinois-licensed professional engineer.

Sources & Official References

[1]Cook County Code of Ordinances — Chapter 106, Floodplains

Other rules in Cook County

Noise Ordinances: Construction HoursSome Restrictions Fence Regulations: Height LimitsSome Restrictions Boat Dock PermitsSignificant Restrictions Vehicle Idling RestrictionsSome Restrictions Flood ZonesHeavy Restrictions Stormwater ManagementSome Restrictions Erosion ControlSome Restrictions Noise Ordinances: Vehicle NoiseSome Restrictions Parking Rules: Towing & Impound RightsSignificant Restrictions Parking Rules: Loading ZonesSome Restrictions Animal Ordinances: Veterinary Clinic ZoningFew Restrictions

All Cook County rules

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Flood Elevation Requirements in Cities Across Cook County

Chicago, IL Evanston, IL Oak Park, IL Schaumburg, IL Arlington Heights, IL Skokie, IL Des Plaines, IL Orland Park, IL Tinley Park, IL Oak Lawn, IL