Bayonne, NJ Environmental Rules: Flood Elevation Requirements (2026)

Chapter 29's specific standards apply once base flood elevation data exists for a site, whether from the Flood Insurance Study adopted at Section 29-3.2 or from other federal, state or engineering data the Construction Official gathers under Section 29-4.3b when FIRM data is unavailable. Under Section 29-6.2a, new construction and substantial improvement of any residential structure must have the lowest floor, including any basement, elevated to or above the base flood elevation shown for the site. Where a parcel instead falls in an AO zone on Bayonne's FIRM, meaning a shallow flooding area mapped with a depth number rather than a base elevation, the same subsection requires the lowest floor to sit above the highest adjacent grade by at least the depth number printed on the map, or at least two feet if the map lists no depth number.

Section 29-6.2a further requires adequate drainage paths around structures built on sloped sites so floodwaters are guided around and away from the building rather than pooling against it. The Construction Official reviews these elevations as part of the development permit process required by Section 29-4.1, and an applicant must document the lowest-floor elevation in relation to mean sea level on the permit application itself. Manufactured homes get a parallel rule at Section 29-6.3b, which requires the top of the lowest floor to sit at or above the base flood elevation once the home is set on a permanent foundation.