Yonkers, NY Hurricane Preparedness: Flood Elevation (2026)

City Code § 56-147C(1) requires a floodplain development permit applicant proposing new construction or a substantial improvement in Zones A1-A30, AE or AH, or Zone A where base flood elevation data exist, to state the proposed elevation of the lowest floor, including any basement or cellar, in relation to mean sea level. Once the lowest floor is complete, the permittee must submit the as-built elevation to the local administrator, certified by a licensed professional engineer or surveyor. Section 56-147D(4)(a) makes this a formal construction-stage checkpoint: upon placement of the lowest floor or completion of floodproofing, the local administrator must obtain from the permit holder a certification of the as-built elevation of the lowest floor or floodproofed elevation, again referenced to mean sea level, prepared by or under the direct supervision of a licensed land surveyor or professional engineer.

Manufactured homes must submit the elevation certificate upon placement on the site, and a recreational vehicle needs one too if it stays on a site 180 consecutive days or longer and is not fully licensed and ready for highway use. Section 56-147D(4)(b) warns that any further work undertaken before the certification is submitted and approved is at the permit holder's own risk, and the local administrator must review the submitted data and issue a stop-work order for any deficiency that is not immediately corrected. The City Engineer, as local administrator under § 56-147A, retains these elevation certifications along with floodproofing certificates and variance records under § 56-147D(8) and makes them available for public inspection.