Franklin Township, PA Environmental Rules: Flood Elevation Requirements (2026)

Franklin Township builds a freeboard margin into its floodplain standards rather than stopping at FEMA's bare 100-year (base) flood elevation. The Code's definitions section, § 27-202, sets 'REGULATORY FLOOD ELEVATION' as the 100-year flood elevation plus a freeboard safety factor of 1 1/2 feet, and that elevated number, not the raw base flood elevation, is the line every Flood Hazard District project must clear. Section 27-1305, Technical Provisions, Subsection 2.A, applies the definition to residential construction: in AE, A1-30, and AH Zones, any new construction or substantial improvement must have its lowest floor, including the basement, elevated up to or above the regulatory flood elevation. In A Zones without mapped base flood elevations, the Township instead uses an elevation derived from the nearest floodplain boundary point under § 27-1304, Subsection 2.C, or, absent any usable data, a minimum of three feet above the highest adjacent grade.

Nonresidential buildings get an alternative under Subsection 2.B: elevate to the regulatory flood elevation or floodproof the space below it so the structure is watertight, with walls able to resist hydrostatic and hydrodynamic loads, following the Army Corps of Engineers' W1 or W2 floodproofing classifications, certified by a registered engineer or architect. Fully enclosed space below the lowest floor, other than a basement, must include flood vents equal to at least one square inch of opening per square foot of enclosed area, split across at least two walls, with openings no higher than one foot above grade. Both the 2009 International Building and Residential Codes and 34 Pa. Code Chapters 401-405 apply on top of these Township rules wherever they are stricter.