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

For a delineated watercourse, the elevation associated with the Best Available Flood Hazard Data Area determined in Section 33-102.2, above plus one foot or as described by N.J.A.C. 7:13 of freeboard; or

b. For any undelineated watercourse (where mapping or studies described in 33-102.2a and b above are not available) that has a contributory drainage area of 50 acres or more, the applicants must provide one of the following to determine the Local Design Flood Elevation:

1. A copy of an unexpired NJDEP Flood Hazard Area Verification plus one foot of freeboard and any additional freeboard as required by ASCE 24; or 2. A determination of the Flood Hazard Area Design Flood Elevation using Method 5 or Method 6 (as described in N.J.A.C. 7:13) plus one foot of freeboard and any additional freeboard as required by ASCE 24. Any determination using these methods must be sealed and submitted according to Section 33-105.2-3.

c. AO Zones. For Zone AO areas on the municipality's FIRM (or on preliminary flood elevation guidance from FEMA), the Local Design Flood Elevation is determined from the FIRM panel as the highest adjacent grade plus the depth number specified plus one foot of freeboard. If no depth number is specified, the Local Design Flood Elevation is three feet above the highest adjacent grade.

d.