New Brunswick, NJ Environmental Rules: Flood Elevation Requirements (2026)

Section 15.36.030.C of the New Brunswick Municipal Code sets the local design flood elevation, or LDFE, for every flood hazard area in the City of New Brunswick. The LDFE starts from the best available flood hazard data, the state Flood Hazard Area Control Act minimum elevations for lowest floors in A, coastal A and V zones, and ASCE 24 requirements for critical facilities, then adds freeboard specified by the chapter. The chapter defines freeboard as a factor of safety expressed in feet above a flood level.

The number depends on the site. For a delineated watercourse the LDFE is the best available flood elevation plus one foot, or the freeboard N.J.A.C. 7:13 describes. For an undelineated watercourse with a contributory drainage area of fifty (50) acres or more, the applicant supplies either an unexpired NJDEP flood hazard area verification or a sealed Method 5 or Method 6 determination, each plus one foot of freeboard and any additional freeboard ASCE 24 requires. In a zone AO area the LDFE is the highest adjacent grade plus the depth number on the FIRM panel plus one foot, and three feet above the highest adjacent grade when no depth number is printed. Class IV critical facilities must meet the higher of the 0.2% annual chance flood elevation or the flood hazard area design flood elevation with two additional feet of freeboard. Class III critical facilities in coastal high hazard areas use one additional foot.

Section 15.36.150.B.1.c then requires the lowest floor of any new or substantially improved habitable building, basement included, together with attendant utilities and sanitary facilities, to sit at or above the LDFE and be confirmed by an elevation certificate. Substantial improvement means cumulative cost equal to or above fifty (50) percent of market value, reviewed over a ten-year period. The city engineer is the floodplain administrator under Section 15.36.040.A, and records the required elevation, determination method and base flood elevation source in the floodplain development permit. Under Section 15.36.070.C an elevation certificate is due when the lowest floor is placed, before further vertical construction, and again before final inspection. Section 15.36.150.G.1 puts the travel surface of any roadway or parking area in a flood hazard area at least one foot above the design elevation.