7 Pitfalls Of Flood Mitigation Strategies

In October 2012, Superstorm Sandy submerged many Downtown Manhattan streets, along with entire neighborhoods throughout the five boroughs. Historic storm surges and floodwaters revealed the inability of New York City’s building stock to weather another storm or survive anticipated sea level rise.

Sandy prompted the Federal Emergency Management Agency to update its Flood Insurance Rate Maps, as well as change building criteria and valuation. As a result, developers’ insurance companies and the Department of Buildings continue to lobby for stronger resiliency measures in the NYC Building Code, FEMA and other standards such as American Society of Civil Engineers 24-14.

NYC has 538 miles of coastline, and more than 84,000 buildings worth over $129B are below the 100-year flood plain. The Federal Emergency Management Agency’s National Flood Insurance Program established flood hazard regulations in 1983 so compliant communities could receive relief. 

Whether you are buying, selling or renovating commercial properties, Vidaris advises CRE pros to watch for these seven common mistakes when it comes to flood prevention and damage mitigation.

1. Assuming your building is safe because it is not near the water

FEMA flood zone maps establish the elevation of the flood plain, which often stretches far inland when the terrain is low-lying. According to Vidaris Senior Principal Robert LiMandri, since new neighborhoods were remapped into flood zones after Sandy, knowing where your property stands today is essential.

2. Assuming your project is exempt because of its limited scope of work

Building codes offer exemption from full flood hazard compliance for properties that predate flood regulations. However, when repairs and upgrades exceed half the market value of the property, they are classified as a “substantial improvement.”

With this designation, further significant upgrades may be required, potentially resulting in lost rentable space below the flood plain. Even if improvements do not exceed that threshold, some work could still be considered a new noncompliance, violating codes.

3. Counting on a variance from the Board of Standards and Appeals

How to approach grandfathered building stock with occupied basements and cellars is a conundrum. Owners may want to implement upgrades to satisfy their flood insurance carriers, but find themselves limited by what the code sanctions.

"Before you start racking up attorney fees on time-consuming variance proceedings, carefully research measures you can actually take that conform with the building code," LiMandri said.

4. Misplacing vital systems

Building codes necessitate elevating building mechanical, electrical and plumbing systems above potential flood zones, but this creates awkward placement of emergency generators, fuel storage tanks, boilers and other mechanical systems. Avoid sacrificing prime real estate square footage by ascertaining which components are safe to leave below the flood plain.

5. Leaving height and floor area bonuses on the table

"If grandfathered portions of your building were destroyed by Sandy, learn about the redefined zoning parameters so that you can rebuild and elevate such conditions to retain your property’s full value," LiMandri said.

For new development, floor area and roof coverage bonuses are now available to offset the spatial requirements of flood resiliency features.

6. Assuming exits will not be required during a flood

Exits must remain open and unobstructed in the event of a flood. Exit doors cannot be blocked by flood shields or held shut by hydrostatic pressure. Knowing where, when and how to elevate exits can help to maximize valuable square footage while ensuring occupant safety.

7. Failing to install actionable systems

Some property owners and managers opt for flood mitigation products that require human intervention. Although these might be within budget, satisfy a flood insurance carrier and work with the building design, they may not be practical in the event of a flood. Spending money on protection without the ability to execute is ultimately a waste.

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