Waukegan, IL Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard
- 2.5 feet above flood protection elevation
- Wall openings
- No lower than elevation plus 2.5 ft
- Basement construction
- Watertight masonry, engineer-sealed design
- Building site grading
- Slopes away from walls, 5 feet min
- Datum
- Mean sea level, New York City
Summary
Waukegan sets its regulatory flood protection elevation 2.5 feet above the mapped high-water profile, and Sec. 6-131 carries that same 2.5-foot freeboard into construction rules, requiring every doorsill, windowsill, or wall opening to sit no lower than that elevation plus 2.5 feet.
(a)Profile drawings and schedules. Profile drawings and schedules provided in United States Geological Survey Hydrological Investigations Atlas, Series HA, dated 1964 through 1971, accompanying and identified as part of this article, are incorporated herein for the purpose of establishing regulatory flood protection elevations on or along the streams, channels and basins established in section 6-93 of this article. The regulatory flood protection elevation shall be 2.5 feet above the attached water surface profiles provided in United States Geological Survey Hydrological Investigations Atlas, Series HA, where a flood of record has not been determined. ... A doorsill, windowsill or the base of any other opening in the outer walls of a main building or structure, including drain conduits, shall be constructed at an elevation not lower than the established regulatory flood protection elevation plus 2.5 feet, unless surrounded by a watertight areaway the top of which is not lower than such minimum elevation.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 113).
Full Breakdown
Sec. 6-95(a) ties Waukegan's regulatory flood protection elevation to the profile drawings and schedules in the USGS Hydrological Investigations Atlas referenced in Sec. 5 feet above the attached water-surface profile. Subsection (b) applies the elevation nearest to a given building, lot, or parcel, measured at right angles to the flow of the adjoining stream or channel, or from the nearest detention pond or basin, whichever produces the higher elevation, and subsection (c) datums those elevations to mean sea level at New York City unless the profile notes a different reference point.
That base elevation then drives the article's construction standards: Sec. 5 feet of freeboard, unless it is protected by a watertight areaway built to that same minimum height. Sec. 5-foot line to be built of watertight masonry engineered by a state-registered architect or engineer to resist hydrostatic pressure, and Sec. 6-133 requires the building site itself to be graded to that height and slope away from the walls for at least five feet.
Violations & Fines
Sec. 6-116 withholds zoning, building, and subdivision permits until a project meets the elevation standards in Sec. 6-95, 6-131, 6-132, and 6-133, so a wall opening, basement, or building pad built below the required flood protection elevation plus 2.5 feet of freeboard cannot receive city approval, and Sec. 6-132's watertight-construction design must carry a licensed architect's or engineer's seal before it is accepted.
Frequently Asked Questions
How much freeboard does Waukegan require above the base flood elevation?
Do basement walls need special construction in a Waukegan flood area?
Can I use a watertight areaway instead of raising a doorsill?
Sources & Official References
Other rules in Waukegan
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