Mountain View, CA Environmental Rules: Flood Elevation Requirements (2026)

Chapter 48 requires elevation compliance to be documented, not just designed on paper. Section 48.14.20 requires that, upon placement of the lowest floor (including any basement) and before further vertical construction proceeds, a CA-licensed land surveyor or civil engineer must certify the elevation required by the building code and submit it to the chief building official, with a second certification due before final inspection; new or substantially improved nonresidential buildings additionally need FEMA floodproofing certification before final inspection. Falling below that elevation is only allowed through the variance process in Article IV, and Section 48.16.05 makes clear the city does not treat that lightly: 'variances from the elevation or other requirements in the building codes should be quite rare' because of the seriousness of property damage and the cost of insuring underelevated structures, and variances are barred outright in floodways where they would raise flood levels (Section 48.16.30).

Where an applicant does seek a variance to build the lowest floor below the base flood elevation, Section 48.16.50(e) requires the floodplain administrator to notify the applicant in writing, specifying the exact difference between the base flood elevation and the proposed lowest-floor elevation, and to state that building below the required elevation 'will result in increased premium rates for federal flood insurance up to amounts as high as twenty-five dollars ($25.00) for one hundred dollars ($100.00) of insurance coverage.' That notice must also flag the increased risk to life and property.

Variances are further conditioned on a showing that the site's unique physical characteristics make compliance an exceptional hardship, that the request is the minimum relief needed, and that granting it will not raise flood heights or endanger the public (Section 48.16.50(a)-(d)).