HiddenRiverCommonAreaBankStabilization_HiwasseeR_Clay_NCWRCComments

North Carolina Wildlife Resources Commission
Cameron Ingram, Executive Director

Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]
October 12, 2023

Ms. Shannon Healy
U.S. Army Corps of Engineers, Regulatory Branch
151 Patton Avenue, Room 208
Asheville, North Carolina 28801-5006

SUBJECT: Hidden River Common Area Bank Stabilization
Hiwassee River, Clay County

Dear Ms. Healy:

Biologists with the North Carolina Wildlife Resources Commission (NCWRC) reviewed an
application to stabilize 80 feet of streambank on the Hiwassee River in Clay 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).

Wild trout reproduction should not be impacted by the project, and activities do not need to be
avoided during the trout moratorium. However, the site is just upstream of the Upper Hiwassee
River Aquatic Habitat, a NC Natural Heritage Program natural area rated Exceptional due to the
richness and ecological significance of species it supports. In the vicinity of the project, a
number of rare and listed species are found, including Christyi’s Elimia (Elimia christyi, NC
Endangered), Rainbow (Villosa iris, NC Threatened), and Eastern Hellbender [Cryptobranchus
alleganiensis, US Federal Species of Concern, NC Special Concern (SC)]. Excellent sediment
and erosion control measures are needed on the project to protect these sensitive species.

The application proposes to address erosion in a 80-ft area of bank with riprap and also install a
set of stairs for access to the river. Instead of riprap, we recommend sloping the banks and
planting them with native vegetation. If rock must be used, we recommend stacking larger
boulders instead of riprap; stacked stone will likely be a longer-term solution. We recommend
incorporating as many native shrubs and trees as possible on the slope as well as the top of the
bank, as native woody vegetation will provide long-term bank stabilization, keep water
temperatures cool, and provide wildlife habitat.

Hidden River Common Area Stabilization Page 2 October 12, 2023
Hiwassee River, Clay Co
We offer the following recommendations to minimize impacts to the aquatic community:
1. 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, preferably at the end of each work day.
2. Bank work should be performed during low flows.
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 sloping the bank and planting it with native woody vegetation instead of
using rock. If rock is used, only clean boulders should be used, and they should be stacked
and backed with a semi-permeable liner.
5. We recommend that the project incorporate as many native trees and shrubs as possible.
Incorporating native wildflowers and grasses is also recommended to provide better habitat
for wildlife such as birds and butterflies. For planting recommendations, please see NC
Cooperative Extension’s guide on small-scale solutions to eroding stream banks and NC
State University’s list of mountain riparian species, attached. In addition, we recommend
reaching out to the streambank restoration staff at Mountain True, who may be able provide
site-specific recommendations ([e-mail], 828-837-5414).

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

Attachments: Small-scale Solutions to Eroding Stream Banks
NCSU mountain riparian species list

ec: Victoria Ewing, Hidden River Estates POA
Joey Winston, NC Division of Water Resources