N.J. Admin. Code § 7:13-12.14

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

Section 7:13-12.14 - Requirements for bank stabilization and channel restoration

(a) This section sets forth specific design and construction standards that apply to any bank stabilization or channel restoration project proposed in any regulated area.

(b) The Department shall issue an individual permit under this section only if the following requirements are satisfied:

1. The applicant provides:

i. A complete written description of the existing erosion, instability, or ecological degradation including:

(1) A history of the site and the watershed;

(2) An explanation of any previous attempts to stabilize or restore the bank or channel; and

(3) The likely causes of any erosion, instability, or ecological degradation proposed to be remedied;

ii. A demonstration of why the selected stabilization or restoration methods (as described at (c) below) are the most suitable for the site. At a minimum, this demonstration should include and discuss the following:

(1) The location of any headcut in the channel if present. A headcut is a sudden change in elevation in the stream bed, which usually occurs at the leading edge of a forming gully, and is indicative of erosive forces that are likely to continue to wash away the natural channel;

(2). Any upstream or downstream stressors that may have contributed to and/or exacerbated any erosion, instability or ecological degradation, which should be addressed as part of the project;

(3) How future development in the watershed could impact the bank and/or channel and the proposed stabilization and/or restoration;

(4). The anticipated lifetime of the proposed stabilization or restoration; and

iii. A maintenance and monitoring plan to ensure the success of the proposed stabilization or restoration, which includes:

(1). An action plan in case of future failure of the project; and

(2) A plan to reduce the likelihood of future erosion, instability and ecological degradation onsite;

2. The project is designed by an individual with experience in fluvial geomorphology (and soil bioengineering if used on site), as evidenced by documentation supplied with the individual permit application; and

3. In cases where nuisance flooding is a related issue, flood capacity outside the regulated water is increased by terracing the overbank areas where appropriate, so that the channel is not forced to convey excessive flows.

(c) The Department shall issue an individual permit to restore to a stable condition a bank or channel, which has become eroded, unstable, and/or ecologically degraded, only if the project is accomplished as follows:

1. Where feasible, a localized eroded bank or destabilized channel is restored solely by cutting back the bank to a stable slope and planting with native, non-invasive plant species suitable for stabilization. Generally a slope of no greater than 50 percent (a ratio of two horizontal to one vertical) is recommended to stabilize an eroded bank;

2. Where the applicant demonstrates that cutting the bank and planting vegetation as described in (c)1 above cannot adequately restore the channel and/or fully prevent erosion due to excessive channel velocity, soil bioengineering shall be used to stabilize the eroded bank and/or restore the channel. In designing soil bioengineering installations, the existing soil characteristics, the bank and/or channel's physical structure, and the hydrologic conditions on site shall be considered; and

3. Where the applicant demonstrates that, given the velocity and configuration of the adjacent channel and/or other conditions of the site, vegetation and/or soil bioengineering alone are not adequate to stabilize the bank and/or restore the channel, the use of revetments, retaining walls, or other armoring to stabilize the bank or channel is conditionally acceptable.

(d) The Department shall issue an individual permit to restore to a natural condition a regulated water that is significantly ecologically degraded, such as a channel enclosed by a pipe or culvert, a channel that has been previously straightened, channelized, or lined with revetments, retaining walls, or other armoring, or a channel that has relocated or become significantly eroded or incised through natural processes, only if the following requirements are satisfied:

1. The project will result in:

i. Ecological enhancement, including habitat creation, restoration, or enhancement;

ii. Riparian zone creation in accordance with N.J.A.C. 7:13-13.10; and/or

iii. Riparian zone restoration in accordance with N.J.A.C. 7:13-13.11;

2. To the maximum extent practicable, all structures enclosing or lining the regulated water are removed;

3. To the maximum extent practicable, the regulated water is restored to its natural condition and configuration, including channel geometry, sinuosity, aquatic habitat, and benthic characteristics;

4. The channel is stabilized using vegetation in accordance with (c)1 above and/or soil bioengineering in accordance with (c)2 above; and

5. The project is designed to minimize adverse impacts to flooding offsite, such that the following requirements are satisfied for any flood event described in 7:13-12.1(i). For the purpose of determining compliance with this subsection, calculations shall be rounded to the nearest 0.1 feet:

i. The proposed construction does not subject any habitable building to increased depth or frequency of flooding;

ii. The proposed construction does not increase offsite flood depths within 500 feet upstream and downstream of the project by more than one foot; and

iii. The proposed construction does not increase offsite flood depths in areas located more than 500 feet upstream and downstream of the project by more than 0.2 feet.

N.J. Admin. Code § 7:13-12.14

Amended and recodified from 7:13-11.14 by 48 N.J.R. 1067(a), effective 6/20/2016

Amended by 49 N.J.R. 2246(a), effective 7/17/2017