Floodplain Management Requirements After a Flood

National Flood Insurance Program Rebuilding Requirements

Many communities in New York are suffering and recovering from extreme flooding. In many areas, flooding has hit record levels or levels not seen in decades. Residents and business owners are understandably anxious to repair damaged building components. Municipalities are already burdened with the necessity to make sure that structures are safe.

Flood Protection Requirements

Rebuilding requirements after a flood or any other disaster must also consider the flood protection requirements contained in community local laws that were passed as a condition of participation in the National Flood Insurance Program. These requirements are also contained in the Residential Code of New York State, the Building Code of New York State and the Existing Building Code of New York State.

Break the Damage - Rebuild - Damage Cycle

A primary goal of the National Flood Insurance Program is to break the damage - rebuild - damage cycle by requiring all new, substantially improved, and substantially damaged structures within mapped flood hazard areas to be constructed in a manner that is reasonably safe from flooding. That requires proper building elevation and protection techniques.

Substantial Damage

• The definition of "substantial damage" is: "damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred." This definition applies whether or not actual repair work is performed.
• FEMA regulations (44 CFR 60.3) require new construction and substantially improved or substantially damaged structures within mapped flood hazard areas to meet specific floodplain development standards.
• The Building Code of New York State, the Existing Building Code of New York State, and the Residential Code of New York State all require substantially damaged buildings in flood hazard areas to meet all of the flood design requirements for new construction. The purpose of these requirements is to make sure that damage is minimized when the next flood occurs.
• It is the responsibility of local communities as participating communities in the National Flood Insurance Program, and as the enforcement agents for the Building Code of New York State, to determine if a damaged structure is in a FEMA mapped flood hazard area and, if so, to determine if the structure has been substantially damaged.
• If a structure has been substantially damaged, it must then meet the flood protection requirements. DEC staff is available to assist your community with the requirements; however we cannot make the substantial damage determinations on your behalf.
• After a federal disaster declaration, FEMA and DEC staff will also be available to provide assistance.

Some Rules of Thumb on Assessing "Substantial Damage"

• As an example, if a structure has been moved off its foundation, it is nearly certain that it has been substantially damaged.
• The U.S. Army Corps of Engineers has estimated that substantially damaged thresholdsare approached once flood waters exceed about two feet above the first floor on a traditionally constructed structure with a basement. If there is no basement, that threshold is approached with about three feet of flood water over the lowest floor. In such situations, a more detailed determination of damages and comparison to the market value of the structure is required.
• FEMA has developed guidance on substantially damaged structures. That can be found in the manual "Answers to Questions about Substantially Damaged Buildings", available on the FEMA Website provided in the right column on this page under "Links Leaving DEC's Website".

Estimating Flood Damages

• FEMA also has an electronic "Substantial Damage Estimator" that can be downloaded from the FEMA Website provided in the right column on this page under "Links Leaving DEC's Website". When determining if a structure has been substantially damaged, you must compare the cost of returning the structure to its before damaged condition to the market value of the structure prior to the damage. Acceptable estimates of "cost of repair" or damage sustained include itemized estimates by a licensed contractor or other professional estimators in the construction industry.
• For structures with a National Flood Insurance Program (NFIP) policy, you may also use the damage estimate by the NFIP claims adjuster for the structure only, not including contents.
• You may also use building code valuation tables published by the major building code groups.
• The building department may use its own professional judgment based on knowledge of local and regional building costs. However, you must be consistent in your judgment. FEMA's "Substantial Damage Estimator" can help, and has withstood legal scrutiny in New York State.
• The market value pertains only to the structure. Market value may be determined by a professional appraiser, or the community may use the adjusted property appraisal for the structure only.
• Other techniques may be used as screening tools. However the closer the damage comes to 50 percent, the greater the accuracy of the determination should be.

Substantial Improvements

Should a structure not be substantially damaged, but the owner decides to provide additions, rehabilitation or other improvements during the repair, you must combine the total cost of repair with the cost of the improvement. If the combined cost equals or exceeds 50 percent of the market value of the structure prior to the damage, it is considered to be a substantial improvement, and the entire structure must meet floodplain development requirements.

Substantial Damage in the Regulatory Floodway

In some cases, a damaged structure may be located within a FEMA designated regulatory floodway. The floodway is a narrower portion of a riverine floodplain and must be kept clear of new development in order to pass flood flows without increasing flood elevations by any measurable amount. If a damaged structure is within the floodway, and has been deemed to be substantially damaged, the structure may be repaired on the same site provided that it is elevated in accordance with floodplain development requirements, and the footprint does not exceed the pre-existing footprint of the structure. If the footprint of the structure expands within the floodway, or if the owner plans to bring fill into the floodway, then an engineering analysis is required to prove that the encroachment does not increase flood elevations.

Do You Need Assistance?

For further assistance on floodplain development requirements during this difficult time, or at any time, please call your regional DEC floodplain management official, or DEC's Floodplain Management Section in Albany at 518-402-8185. The table below provides DEC floodplain Staff contact information.

Central Office Floodplain Management Coordinators

• Dave Sherman - Environmental Program Specialist
• Brad Wenskoski - Environmental Program Specialist, Code Enforcement Official
• Mary Martin - Environmental Program Specialist
• Geoff Golick - Environmental Engineer
• Kelli Higgins-Roche - Environmental Engineer

Western NY Flood Hub, Assisting with Regions 6-9

• Karis Manning - Environmental Engineer
• Brienna Wirley - Environmental Program Specialist

Regional Floodplain Management Coordinators

• Find on this Page
• • Do You Need Assistance?
• Links Leaving DEC's Website
• • Answers to Questions about Substantially Damaged Buildings
  • Substantial Damage Estimator
• PDF Help
• For help with PDFs on this page, please call 518-402-8185.
• Contact for this Page
• Division of Water
  Bureau of Flood Protection and Dam Safety
  625 Broadway
  Albany New York 12233-3504
  518-402-8185
  Send us an email
• This Page Covers
•