Westminster, CO Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Governing sections
- W.M.C. Sections 11-8-2, 11-8-13(B)
- Freeboard requirement
- 1 foot above BFE (known-BFE areas)
- Unknown-BFE areas
- 2 ft above nearest street gutter flowline
- AO zones
- 3 ft above grade or depth+1 ft
- Applies to
- New construction & substantial improvements
Summary
Westminster requires new construction in a mapped floodplain to elevate the lowest floor one foot above the base flood elevation, and three feet above grade in AO zones, under Section 11-8-13(B) and the freeboard definition in Section 11-8-2.
Freeboard shall mean the vertical distance in feet above a predicted water surface elevation intended to provide a margin of safety to compensate for unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood... (B)Residential Structures:(2)In floodplain areas in which the base flood elevation (BFE) is known, all new construction and substantial improvements of residential construction shall have the lowest floor, including basement, elevated one foot above the BFE as indicated in the flood insurance study (FIS).
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 12).
Full Breakdown
Section 11-8-2 defines "Freeboard" as "the vertical distance in feet above a predicted water surface elevation intended to provide a margin of safety to compensate for unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood," and defines "Base flood elevation (BFE)" as the elevation on a FEMA flood insurance rate map for zones such as AE, AH, and VE representing the one-percent-annual-chance flood level. " Where the BFE is not known, the lowest floor must instead sit two feet above the gutter flowline of the nearest street.
In an AO zone, structures must be elevated three feet above the highest adjacent grade if no depth number is specified in the FIS, or at least one foot higher than the specified depth number. Subsection (C) applies the identical one-foot BFE freeboard and two-foot/three-foot alternatives to non-residential structures, with an added floodproofing option certified by a registered professional engineer. Subsection (K) applies the same one-foot freeboard above the prior BFE to any new construction on land removed from the floodplain by a FEMA LOMR-F.
Violations & Fines
Constructing or substantially improving a structure below the required one-foot BFE freeboard, or below the AO-zone elevation standard, without an approved floodproofing certification violates Section 11-8-13 and is subject to the Floodplain Administrator's permit review and denial under Subsection (J), with variances available only from the Director of Community Services or City Council on a showing of exceptional hardship under Section 11-8-18.
Frequently Asked Questions
How much freeboard does Westminster require above base flood elevation?
What if the base flood elevation is not known for my Westminster property?
Does Westminster have different elevation rules for AO flood zones?
Sources & Official References
Other rules in Westminster
Compare Westminster to another location·View the Colorado environmental rules overview
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Flood Elevation Requirements in Nearby Cities
How other cities in Adams County handle flood elevation requirements.