Clifton, NJ Environmental Rules: Flood Elevation Requirements (2026)

Chapter 239, § 239-12 sets Clifton's local design flood elevation (LDFE) using the best available flood hazard data from § 239-11, the Flood Hazard Area Control Act's statewide minimum elevation requirements for lowest floors in A, Coastal A and V Zones, ASCE 24 requirements for critical facilities, plus additional freeboard set by the chapter (§ 239-12A). C. 7:13; an undelineated watercourse with 50 or more acres of drainage area requires either an unexpired NJDEP Flood Hazard Area Verification plus one foot of freeboard, or a sealed engineering determination under FHACA Method 5 or 6 plus one foot of freeboard and any additional ASCE 24 freeboard (§ 239-12B(1), (2)).

In AO Zones, the LDFE is the FIRM's highest adjacent grade plus the specified depth number plus one foot of freeboard, or three feet above grade if no depth number is given (§ 239-12B(3)). Class IV critical facilities must clear the higher of the 500-year flood elevation or the flood hazard area design flood elevation plus two feet of freeboard, while Class III critical facilities in coastal high hazard areas need one additional foot (§ 239-12B(4), (5)). Section 239-74 then requires the lowest floor, including basement, of new construction and substantial improvements of habitable buildings, along with attendant utilities and sanitary facilities, to be elevated to or above that § 239-12 LDFE and confirmed by an elevation certificate.