20070721 Ver 2_WRC Comments_20220201

North Carolina Wildlife Resources Commission
Cameron Ingram, Executive Director
February 1, 2022
Mr. David Brown
U.S. Army Corps of Engineers, Regulatory Branch
151 Patton Avenue, Room 208
Asheville, North Carolina 28801-5006
SUBJECT: North Fork Reservoir Dredging
North Mills River and wetlands, Henderson County
Dear Mr. Brown:
Biologists with the North Carolina Wildlife Resources Commission (NCWRC) reviewed an
application to temporarily dewater and dredge the North Fork Reservoir, impacting 0.076 acre of
wetland and 0.618 acre of open water in Henderson County. Our comments on this application
are offered for your consideration under provisions of the Clean Water Act of 1977 (33 U.S.C.
466 et. seq.) and Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-
667d).
There are wild Rainbow Trout in the North Mills River, and normally, project activities should be
avoided between January 1 and April 15 to minimize impact to trout reproduction. However, the
Eastern Hellbender (Cryptobranchus alleganiensis, US Federal Species of Concern, NC Special
Concern) is found downstream in the North Mills River. The hellbender reproduction period
(breeding, nesting, and hatchling development) is generally August 15 to November 30. The
applicant estimates that the project will take 6 months to complete and proposes a timeframe of
April 16 to October 14, 2022. In order to minimize potential sediment impacts from project
activities to hellbender reproduction, we recommend that the project begin as soon as possible
instead of waiting until April 16. Both hellbenders and wild trout are especially sensitive to
excess sediment and effective erosion and sediment control is essential to minimize impacts to
them.
The North Fork Reservoir serves as a water supply source for the City of Hendersonville, which
proposes to dredge the impoundment and perform valve repairs if needed. Hydro -dredging was
last performed 15 years ago, but mechanical dredging is proposed for this project. The reservoir
would be lowered by 9 ft either with a surface siphon and released over the dam or to the intake
to the water treatment plant (WTP). A downstream release of 8 ft3 would be maintained at all
Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]

North Fork Reservoir Dredging Page 2 February 1, 2022
N. Mills R, Henderson Co.
times via siphon; the gate valve will remain closed during reservoir lowering and dredging. The
siphons will be surrounded by turbidity curtains, and turbid water will be allowed to settle in the
reservoir pool or sent to the WTP for treatment.
The applicant proposes to dredge the reservoir in two stages — first on the Big Creek arm of the
reservoir, and second on the Fletcher Creek arm. Temporary access would be provided with a
ramp and stream crossing on Fletcher Creek. During both stages, the stream flowing through the
dredge area (Big Creek or Fletcher Creek) would be diverted around the work area through a
lined channel
Isolated animals within the pond would be rescued and moved upstream or downstream. We
recommend relocating animals to relatively still waters where they will not be swept away by
current; NCWRC staff can advise the applicant as to the best location in the field.
Approximately 7,500 yd3 of sediment will be dredged and hauled to the Hendersonville WTP.
Once dredging is complete, water will be rediverted back into the channel and reservoir.
A new sediment release protocol will be implemented by adjusting the height of the gate valve,
with the gate valve set to release at least 8 ft3 at all times, with the valve opened wider to match
watershed inflow while maintaining full pool. Storm event flushing releases will be
implemented in the following manner: for any rain event of <0.5 in during a running 24-hr
period, the gate valve will be opened fully until flow over the weir ceases. The downstream
channel will be monitored quarterly for 3 years at 6 established cross sections to determine
changes in channel dimensions.
The City of Hendersonville has been purposeful about coordinating with the agencies on this
project, and we appreciate the consideration that they have given to NCWRC's concerns and
recommendations. We offer the following recommendations to minimize impacts to the aquatic
community:
1. Rather than beginning the project after April 15, we recommend beginning the project as
soon as possible in order to minimize work during the hellbender reproduction period of
August 15 to November 30.
2. Work should be accomplished as quickly as possible and vigilance used in sediment and
erosion control during site preparation, construction, and clean up. Disturbed areas should be
seeded, mulched and/or matted as soon as possible.
3. Any erosion control matting used should be free of plastic or nylon mesh, as this type of
mesh netting frequently entangles wildlife and is slow to degrade, resulting in a hazard that
may last for years.
4. We recommend that turbidity of the water released to the North Mills River be monitored
daily and a contingency plan involving best management practice and operation adjustments
be developed in case of high turbidity originating from project activities.
5. Please notify Andrea Leslie ([e-mail]) and Lori Williams
([e-mail]) at least 3 weeks before mobilization. In addition, consult with
Andrea Leslie as to the best relocation site for animals rescued from the reservoir.

North Fork Reservoir Dredging Page 3 February 1, 2022
N. Mills R, Henderson Co.
Thank you for the opportunity to review and comment on this project. Please contact me at
[phone] if you have any questions about these comments.
Sincerely,
Andrea Leslie
Mountain Region Coordinator, Habitat Conservation Program
ec: Tyson Kurtz, Clearwater Environmental
Andrew Moore, NC Division of Water Resources
Luke Etchison, Chris Goudreau, Powell Wheeler, and Lori Williams, NCWRC
Byron Hamstead, US Fish and Wildlife Service