Vallejo, CA Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard requirement
- 0.5 ft above base flood elevation
- AO zone standard
- 2 ft above grade if no depth listed
- Governing section
- VMC Sec. 7.98.160(C)(1)
- Certification required from
- Registered engineer or surveyor
- Applies to
- New/substantially improved residential structures
Summary
Vallejo requires new and substantially improved residential structures in a mapped flood zone to elevate their lowest floor, including any basement, at least one-half foot above the base flood elevation. Municipal Code Section 7.98.160(C)(1) sets that half-foot freeboard citywide, with a taller two-foot standard in AO zones lacking a mapped flood depth.
1. Residential construction, new or substantial improvement, shall have the lowest floor, including basement: a. In AE, AH, A1-30 zones, elevated to one-half foot or more above the base flood elevation. b. In an AO zone, elevated above the highest adjacent grade to a height equal to or exceeding one-half foot higher than the depth number specified in feet on the FIRM, or elevated at least two feet above the highest adjacent grade if no depth number is specified. c. In an A zone, elevated to or above one-half foot higher than the base flood elevation; said base flood elevation shall be determined by one of the methods in Section 7.98.140B. d. In all other zones, elevated to or above one-half foot higher than the base flood elevation.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Update 12 - 25).
Full Breakdown
160(C) of Vallejo's floodplain management chapter sets the elevation standard, commonly called freeboard, that new and substantially improved residential structures must meet within areas of special flood hazard. In AE, AH, and A1-30 zones, the lowest floor, including any basement, must be elevated to one-half foot or more above the base flood elevation, the elevation of the flood with a one-percent annual chance of occurring, also called the 100-year flood. In an AO zone, where the FIRM specifies a flood depth number, the structure must be elevated above the highest adjacent grade to a height at least one-half foot higher than that depth number, or at least two feet above the highest adjacent grade if no depth number is shown.
140(B), and in any other zone the same half-foot-above-base-flood-elevation standard applies. 160(C) requires the lowest floor elevation to be certified by a registered professional engineer or surveyor and verified by the city's building inspector, with that certification provided to the floodplain administrator. 190.
Violations & Fines
Constructing or substantially improving a residential structure below the required freeboard elevation violates Section 7.98.160(C) and, through Section 7.98.080, is a public offense punishable under the citywide general penalty in Section 1.12.010, up to a $500 infraction fine or a $1,000 misdemeanor fine and up to six months in county jail. Because a structure built below the certified elevation lacks the certification the code requires, Section 7.98.050's definition of 'violation' treats missing elevation certification as a presumed violation until documentation showing compliance is provided.
Frequently Asked Questions
How high above base flood elevation must a Vallejo home be built?
What is the elevation rule in a Vallejo AO flood zone?
Who certifies the elevation of a new building in Vallejo's flood zones?
Sources & Official References
Other rules in Vallejo
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Flood Elevation Requirements in Nearby Cities
How other cities in Solano County handle flood elevation requirements.