Building in a flood zone in Vallejo: the local rules

Each rule below links to the section of the Vallejo Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What Vallejo's code says

Vallejo code What Vallejo's code adds
Building in a floodway	No encroachment unless a registered professional engineer certifies no increase in base flood elevation. Applies: Designated floodways. § 7.98.210 · code text Prohibit encroachments, including fill, new construction, substantial improvement, and other new development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in [the base] flood elevation during the occurrence of the base flood discharge. No development unless all development combined raises the base flood level no more than 1 foot. Applies: In zones A1-30 and AE, until a regulatory floodway is designated. § 7.98.210 · code text Until a regulatory floodway is designated, that no new construction, substantial improvements, or other development (including fill) shall be permitted within zones A1-30 and AE on the city's FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community.
Height of the lowest floor	At least ½ foot above the base flood elevation. Applies: New or substantially improved homes in AE, AH and A1-30 zones. § 7.98.160 · code text In AE, AH, A1-30 zones, elevated to one-half foot or more above the base flood elevation. At least ½ foot above the FIRM depth number, measured from the highest adjacent grade. Applies: New or substantially improved homes in an AO zone with a depth number. § 7.98.160 · code text 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. At least 2 feet above the highest adjacent grade. Applies: New or substantially improved homes in an AO zone when the FIRM gives no depth number. § 7.98.160 · code text 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. At least ½ foot above the base flood elevation. Applies: New or substantially improved homes in an A zone. § 7.98.160 · code text 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. At least ½ foot above the base flood elevation. Applies: New or substantially improved homes in other flood zones. § 7.98.160 · code text In all other zones, elevated to or above one-half foot higher than the base flood elevation.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What are the rules for building in a Vallejo flood zone?

Vallejo's code: At least ½ foot above the base flood elevation. (New or substantially improved homes in AE, AH and A1-30 zones.) (§ 7.98.160); At least ½ foot above the FIRM depth number, measured from the highest adjacent grade. (New or substantially improved homes in an AO zone with a depth number.) (§ 7.98.160).

Building in a flood zone in Vallejo

What Vallejo's code says

Who this affects

Frequently asked questions

Ask about a specific Vallejo property

More on building on your lot in Vallejo