N.J. Admin. Code § 7:13-3.5

Current through Register Vol. 56, No. 21, November 4, 2024

Section 7:13-3.5 - Flood hazard area determined by approximation (Method 5)

(a) This section sets forth the procedure for approximating a flood hazard area design flood elevation using the method described in chapter Appendix 1. This method does not provide a floodway limit. Therefore, the Department shall issue an authorization under a general permit or an individual permit for a regulated activity within an approximated flood hazard area only if the project meets the requirements at (f) below.

(b) The flood hazard area design flood elevation for a regulated water can be approximated under Method 5, provided the following requirements are satisfied:

1. Method 1 (Department delineation method) set forth at 7:13-3.3 cannot be used because no Department delineation exists for the section of regulated water in question;

2. Methods 2 through 4 (FEMA fluvial, FEMA tidal, and FEMA hydraulic methods) set forth at 7:13-3.4 cannot be used because no qualifying FEMA flood mapping exists for the section of regulated water in question; and

3. The drainage area of the water at the project site does not exceed 30 square miles.

(c) An applicant may elect to establish the approximate flood hazard area limit at an elevation higher than that which is provided by Method 5 in order to match an existing topographic feature onsite, such as the top of an embankment, or to run concurrent with a verified freshwater wetland or transition area line.

(d) Method 5 is intended to be conservative and may in some cases overestimate the actual limits of flooding onsite to ensure that public health, safety, and welfare is adequately protected in absence of a Department delineation or FEMA flood mapping.

(e) If the Department determines that using Method 5 to approximate a flood hazard area will significantly underestimate the depth of flooding on a particular site due to an unusual hydrologic or hydraulic condition within the drainage area, or due to a unique feature on or near the site, the Department shall not approve a general permit authorization or an individual permit for any regulated activity in the approximated flood hazard area if such approval is determined to constitute a threat to public safety. Should the applicant choose to apply for a permit in such a case, the flood hazard area limit shall first be calculated according to Method 6, as described at 7:13-3.6.

(f) The Department shall issue an authorization under a general permit or an individual permit for a regulated activity in a flood hazard area approximated under Method 5 only if the flood hazard area is verified under N.J.A.C. 7:13-5 and the Department determines, based on a visual inspection of submitted site plans and without a review of calculations, that one of the following requirements is satisfied:

1. No fill or aboveground structure is proposed within a flood hazard area; or

2. Both of the following are true:

i. Any proposed fill and/or aboveground structure is located outside a floodway; and

ii. The flood storage displacement requirements of 7:13-11.4 are satisfied.

N.J. Admin. Code § 7:13-3.5

Amended by 48 N.J.R. 1067(a), effective 6/20/2016