20201004 Ver 1_WRC Comments_20200930

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]
September 30, 2020

Mr. David Brown
U.S. Army Corps of Engineers, Regulatory Branch
151 Patton Avenue, Room 208
Asheville, North Carolina 28801-5006

SUBJECT: Slusher – Sapphire Farm
Thompson River, UTs, and wetlands, Transylvania County

Dear Mr. Brown:

Biologists with the North Carolina Wildlife Resources Commission (NCWRC) reviewed an
application to impact 0.402 acre of wetland and 279 ft of the Thompson River and unnamed
tributaries (UTs) in Transylvania County. I have visited the site twice, most recently with the
landowner to discuss proposed activities on September 8, 2020. 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 Brook Trout, Brown Trout, and Rainbow Trout are found in the project vicinity, and in-stream
and in-lake activities should be avoided between October 15 and April 15 to minimize impacts to
trout reproduction. In addition, the Thompson River supports the rare Chauga Crayfish (Cambarus
chaugensis, NC Special Concern). Effective erosion and sediment control on this project is essential
to protect these species and their habitats.

A 22-acre Swamp Forest Bog and Southern Appalachian Bog complex is also found on the site. This
wetland is part of the NC Natural Heritage Program-recognized Thompson River Headwater Flats
natural area. 3.4 acres of the bog portion of this wetland were managed in 2019, with shrubs and
trees removed to open canopy, benefiting herbaceous species, including Cuthbert’s Turtlehead
(Chelone cuthbertii, US Federal Species of Concern, NC Special Concern). The applicant may
perform further wetland management but will coordinate with NCWRC on future activities; we look
forward to working with the landowner and his consultants to benefit this important habitat.

Proposed project impacts are associated with lake enlargement, dam repairs, road layout changes,
and aesthetic elements on the site of a former camp, as follows:

 The lake footprint will be enlarged, permanently flooding 0.328 acre of wetland; these
impacts are projected to be offset by the construction of a littoral shelf that is expected to
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Thompson R & UTs, Transylvania Co
support 0.71 acre of future wetland. The dam and outlet structures will be improved,
resulting permanent impacts to 88 ft of an UT to the Thompson River impacts due to flooding
and fill, as well as fill of 0.05 acre of wetland. A new coldwater release structure will be
installed.

The lake will be drained via a bottom drain that is regularly used and drains directly to the
Thompson River. Lake levels will be lowered approximately 4 ft to expose work areas
around the edge of the lake. These areas will be dredged and reshaped. According to Matt
Fusco, areas will be allowed to dry out for 2-3 weeks before work commences. Work areas
will be surrounded by a double row of silt fence, and any runoff from the work areas will be
directed to sediment traps. Flows will be pumped around any work area that has flow.

We are concerned about sediment loss from this work. It is extremely important that this
work be done with effective sediment and erosion control measures. Work should be phased
so that work areas can be stabilized as soon as possible. Due to the presence of Brook Trout
in the Thompson River, we recommend pumping flows around the lake entirely so that the
lake can function as a backup settling basin.

 Road-related impacts include the removal of two existing 20-ft culverts on UTs to the
Thompson River and fill of 0.019 acre of wetland for road improvement and installation of a
timber bridge. An existing bridge set on a weir would be modified, increasing the pool size
behind the weir, flooding an additional 61 ft of an UT to the Thompson River.

 Aesthetic improvements are proposed by the construction of a large pool on the Thompson
River with a structure set on bedrock consisting of a large stacked rock structure followed by
two downstream steps consisting of smaller stacked rocks. Upstream of this, 75 ft of left
descending bank of the resulting pool would be stabilized with large rock. The rock structure
would fill 15 ft of river.

We are concerned that the in-stream structure will cause upstream and/or downstream
channel instability. Given that it is to be set on bedrock, the structure may not remain stable
under high flow events. The first set of larger rocks will be keyed into the bedrock by
drilling into the bedrock and securing the rocks with grout and epoxy, but this may not be
sufficient under high flows; in addition, it is unclear if the two step-down structures of
stacked stone (which will be set in notches cut out of the bedrock) will remain stable given
their bedrock base. If a structure is constructed, we strongly recommend that the structure be
reviewed and designed by a stream restoration engineer with restoration experience in
western North Carolina to ensure stability and aquatic organism passage.

Rhododendron-dominant understory has been cleared within the riparian area along the Thompson
River. This shrub layer is extremely important in providing organic matter to the river (fueling the
stream food web), in stabilizing stream banks, in supplying shade and moderating water temperature,
and in providing structure for riparian wildlife. A riparian corridor like that of the Thompson River
provides resting and browsing habitat for migrating songbirds, and cover provided by a thick shrub
layer is an important element of this habitat. Rhododendron itself provides nesting habitat for
Swainson’s Warbler and cover for other nesting species, such as Black-throated Blue Warbler.

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Thompson R & UTs, Transylvania Co
We appreciate the landowner’s efforts to conserve the diverse and important aquatic and terrestrial
resources on site, as well as his coordination with agencies on his activities. We offer the following
recommendations to minimize impacts to fish and wildlife:

1. In-channel 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 workday.
2. Disturbed stream banks should be seeded with a native riparian seed mix and planted with native
shrubs and trees.
3. Restore and conserve the shrub layer (including Rhododendron) within the riparian corridor to
benefit the Thompson River and riparian wildlife such as songbirds.
4. Any erosion control matting used should be free of plastic or nylon mesh, as this type of mesh
frequently entangles wildlife and is slow to degrade, resulting in a hazard that may last for years.
5. In-stream and in-lake activities should be avoided between October 15 and April 15 to minimize
impacts to wild trout reproduction.
6. We are concerned about the risk of stream channel and structure instability and resulting issues
with aquatic organism passage posed by the proposed in-stream structure on the Thompson
River. If such a structure is constructed, we recommend that it be reviewed and designed by a
stream restoration engineer with experience in western NC.
7. Any grout and epoxy used in-stream should be allowed to fully cure in the dry to avoid in-stream
toxicity.
8. We recommend diverting flows around the lake entirely during in-lake dredging and reshaping
activities.
9. Please reach out to Andrea Leslie at [e-mail] to discuss additional wetland
management activities. Also, please note that any bog clearing to benefit Cuthbert’s Turtlehead
should be done outside the reproduction window of that species.

Thank you for the opportunity to review and comment on this project. Please contact me at (828)
400-4223 if you have any questions about these comments.

Sincerely,

Andrea Leslie
Mountain Region Coordinator, Habitat Conservation Program

ec: Shannon Slusher, landowner
Matt Fusco, Fusco Land Planning and Design
Kaylie Yankura, NC Division of Water Resources
Byron Hamstead, US Fish and Wildlife Service
Jake Rash, NCWRC