Troy, NY Environmental Rules: Flood Elevation Requirements (2026)

Section 158-4 of the Troy City Code sets the general standards inside the area of special flood hazard in the City of Troy, New York, in Rensselaer County. Subsection E covers residential construction: new construction and substantial improvement of any residential structure must have the lowest floor, including basement, elevated to at least six inches above base flood elevation. Under § 158-3 the base flood is the flood with a one-percent chance of being equalled or exceeded in any given year, and substantial improvement means any repair, reconstruction or improvement costing 50% or more of the structure's market value.

Subsection F covers commercial, industrial and other nonresidential structures. They either elevate the lowest floor, including basement, to at least six inches above the base flood elevation, or floodproof the structure and its utility and sanitary facilities so that less than six inches above the base flood level it is watertight with walls substantially impermeable to water. That option also requires structural components that resist hydrostatic and hydrodynamic loads and buoyancy, and a registered professional engineer or architect must certify the design. The certificate, which records the specific elevation to which the structure is floodproofed, goes to the City Engineer or a designee.

Subsection G requires manufactured homes placed or substantially improved within Zones A1-30 to sit on a permanent foundation with the lowest floor at least six inches above base flood elevation, and § 158-4 A(2)(e) ties the elevated foundation to FEMA 85, published in September 1985. Fully enclosed areas below the lowest floor need at least two openings with a total net area of not less than one square inch for every square foot of enclosed area, with the bottom of every opening no higher than one foot above grade, unless an engineer or architect certifies another design. Under § 158-5 B(3) the Director of Code Enforcement records the actual elevation of the lowest habitable floor, in relation to mean sea level, of every new or substantially improved structure.