Millcreek, PA Environmental Rules: Flood Elevation Requirements (2026)

Section 70-78 of the Code of the Township of Millcreek sets elevation and floodproofing requirements for development in the identified floodplain, and the benchmark is the regulatory flood elevation. Section 70-59 defines it as the base flood elevation (BFE) plus a freeboard safety factor of 1 1/2 feet. The base flood elevation is the water surface elevation shown on the FIRM for a flood with a one-percent or greater chance of being equaled or exceeded in any given year.

For residential structures, new construction or substantial improvement in AE, A1-30 and AH zones needs the lowest floor, basement included, elevated up to or above the regulatory flood elevation. In A and V zones where the FIRM shows no base flood elevations, the same standard applies, with the elevation determined under § 70-74C(2). In AO zones the lowest floor sits at or above the highest adjacent grade at least as high as the depth number specified on the FIRM. Nonresidential buildings have a second route: they must be elevated to the regulatory flood elevation or be floodproofed watertight below it, to the W1 or W2 classification in the Army Corps of Engineers publication Flood-Proofing Regulations or an equivalent standard, with plans accompanied by a statement certified by a registered professional engineer or architect.

Substantial improvement means work whose cost equals or exceeds 50% of the market value of the structure before the start of construction, and it includes substantial damage. Fully enclosed space below the lowest floor used solely for parking, building access or incidental storage needs at least two openings with a net total area of not less than one square inch for every square foot of enclosed space, with the bottom of all openings no higher than one foot above grade. Accessory structures need not be elevated if floor area does not exceed 100 square feet, they are not used for habitation, and power lines and outlets are elevated to the regulatory flood elevation. A permit application under § 70-63 must show the proposed lowest floor elevation based on the North American Vertical Datum of 1988.