Monroe Township (Middlesex County), NJ Environmental Rules: Flood Elevation Requirements (2026)

Section 44-12 sets the local design flood elevation, or LDFE, for every project in a flood hazard area. It starts from the best available flood hazard data, the Flood Hazard Area Control Act minimum statewide elevation requirements for lowest floors in A, Coastal A and V Zones, and ASCE 24 requirements for critical facilities, then adds freeboard. For a delineated watercourse the minimum is the elevation of the best available flood hazard data area plus one foot of freeboard, or as N.J.A.C. 7:13 describes. For an undelineated watercourse with a contributory drainage area of 50 acres or more, the applicant supplies either an unexpired NJDEP flood hazard area verification plus one foot of freeboard and any additional freeboard ASCE 24 requires, or a Method 5 or Method 6 determination under N.J.A.C. 7:13 plus the same freeboard, sealed and submitted under § 44-35A(3). Zone AO areas use the highest adjacent grade plus the depth number specified plus one foot, and three feet above the highest adjacent grade when no depth number is specified. Class IV critical facilities must meet the higher of the 0.2% annual chance (500-year) flood elevation or the flood hazard area design flood elevation with an additional two feet of freeboard, and Class III critical facilities in coastal high hazard areas get one additional foot.

Section 44-74 applies the LDFE: new construction and substantial improvement of a habitable building must have the lowest floor, including basement, and attendant utilities elevated to or above the LDFE and confirmed by an elevation certificate. Section 44-17 bars using changed base flood elevations until a CLOMR application is filed and FEMA approves, and § 44-19 lets the Floodplain Administrator require applicants to obtain data or have a licensed professional engineer determine the elevation when none is specified.