NYS Expands Flood Regulatory Framework with 500-Year and Sea Level Rise Provisions

ByMary Bart

On Dec. 31, 2025, New York State’s newest edition of the Uniform Fire Prevention and Building Code (the “2025 Uniform Code”) took effect, embedding climate-informed flood provisions that significantly expand where and how flood-resistant construction standards apply statewide, not counting New York City. The update reflects a thoughtful integration of modern flood risk science into building regulation—particularly through expanded regulatory flood hazard areas, refined elevation terminology, and explicit recognition of sea level rise in tidal areas.

Expanding the Regulatory Flood Hazard Area

A defining advancement in the 2025 Code is the expansion of the regulatory flood hazard area to include 0.2-percent annual chance flood zones (the 500-year floodplain). Under the updated provisions in Section R306 of the Residential Code (RCNYS) and Section 1612 of the Building Code (BCNYS), the regulatory framework now applies flood-resistant construction requirements to moderate flood hazard areas—shown on FIRMs as Zone B and Zone X (shaded).

Although the elevation requirement within these 500-year zones remains tied to the base flood elevation (BFE) associated with the 1-percent annual chance flood event, the expansion ensures that a broader set of buildings and infrastructure are evaluated for flood risk and constructed to consistent, resilient standards. For practitioners and communities, this shift represents a meaningful step toward addressing risk beyond the traditional 100-year footprint. Further, the expansion of the regulatory flood hazard area is consistent with a major provision of the newly published national consensus standard for flood resilient buildings, ASCE 24-24.  

Introducing Required Flood Elevation and Integrating Freeboard

The 2025 Uniform Code introduces the new term Required Flood Elevation (RFE)—a unifying concept for establishing elevation requirements across flood hazard areas. As defined in Section R306.1.4, the RFE is established as the greater of:

  • The base flood elevation for the applicable flood source, plus:
    • 2 feet of freeboard; and
    • An additional 18 inches for sea level rise in flood hazard areas adjacent to tidal waters; or

  • The elevation of the design flood associated with flood hazard areas depicted on a community’s adopted flood hazard map.

The continued requirement for 2 feet of freeboard remains an important buffer above the base flood, enhancing protection against events that exceed minimum expectations, or where regulatory mapping does not keep pace with natural or anthropogenic changes over time. Incorporating freeboard into the Required Flood Elevation calculation reflects longstanding best practices, while the expanded application into moderate hazard zones acknowledges that risk does not stop at the edge of the SFHA.

Accounting for Sea Level Rise in Tidal Areas

A key change to the 2025 Uniform Code is the explicit inclusion of sea level rise (SLR) considerations in tidal coastal areas. As noted in the Regulatory Impact Statement supporting the Code: 

“In both the Residential Code and Building Code, provisions for sea level rise in tidal coastal areas were added that increased the required flood elevation by adding an additional 18 inches in tidal areas over current code requirements, based on recommendations from DEC. This provision is based on the Title 6 Part 490 Projected Sea Level Rise medium sea level rise scenario projections for the 2050s.”
(Regulatory Impact Statement, Appendix B, p. 33,)

The net effect is an additional 18-inch elevation requirement added to the base flood elevation plus freeboard for tidal adjacent areas. This provision is grounded in the New York State Department of Environmental Conservation’s projected SLR medium scenario for the 2050s and reflects a recognition that regulatory design must anticipate emerging conditions—not just historical flood risk.

Technical Considerations and Implementation Guidance

While the expansion of the regulatory flood hazard area and the establishment of the Required Flood Elevation framework are conceptually straightforward, practical challenges remain when multiple flood zones or complex site conditions are present. For example, determining the appropriate base flood reference where adjacent zones have different BFEs, or where AO zones are involved, can present technical ambiguity.

To support consistent interpretation, the New York State Department of Environmental Conservation (DEC) Division of Water has prepared a draft technical bulletin that will soon be published by the New York State Department of State to address these and other unique scenarios.

DEC Division of Water is also updating the model flood damage prevention ordinances and developing a Code Coordinated ordinance to reflect the 2025 Uniform Code provisions, with a goal of assisting communities to align local floodplain management ordinances with updated state requirements.

Similar Posts