Medford, MA Environmental Rules: Flood Elevation Requirements (2026)

Section 46-112, the specific standards provision of Medford's Flood Damage Prevention ordinance, applies once base flood elevation data has been provided for a parcel under Section 46-35 or Section 46-73. For residential construction, new buildings and substantial improvements, meaning work costing 50 percent or more of the structure's market value under Section 46-32's definition, must have the lowest floor, including the basement, elevated to or above the base flood elevation shown on the FIRM. Medford's ordinance does not add a freeboard buffer above that mapped elevation; it requires the lowest floor at or above the mapped base flood elevation itself.

Commercial, industrial and other nonresidential structures have a second compliance path: instead of elevating the lowest floor, the owner may floodproof the building below the base flood level so the walls are watertight and substantially impermeable to water, with structural components able to resist hydrostatic and hydrodynamic loads and the effects of buoyancy. That floodproofing must be certified by a registered professional engineer or architect, and the certification is filed with the city engineer under Section 46-74. Section 46-73 lets the city engineer use federal, state or other available base flood elevation data when the FIRM itself does not provide it for a given site, so that the elevation and floodproofing standards in Section 46-112 can still be applied.

A development permit under Section 46-77 must show the elevation of the lowest floor and any floodproofing before construction can begin, and the city engineer reviews that information against the Section 46-112 standard. Noncompliant construction is subject to the general enforcement and penalty provisions of Section 46-36 and Section 1-13.