20200121 Ver 1_WRC Comments_20200218

0 North Carolina Wildlife Resources Commission 0
Gordon Myers, Executive Director
February 18, 2020
Mr. David Brown
U.S. Army Corps of Engineers, Regulatory Branch
151 Patton Avenue, Room 208
Asheville, North Carolina 28801-5006
SUBJECT: Moose Branch Subdivision
UT to Mauney Branch, Graham County
Dear Mr. Brown:
Biologists with the North Carolina Wildlife Resources Commission (NCWRC) reviewed an
application to permanently impact 125 ft of an unnamed tributary (UT) to Mauney Branch and
0.043 acre of wetland, as well as temporarily impact 50 ft of the UT and 0.019 acre of wetland,
in order to construct a road, water and sewer lines, and other infrastructure for a subdivision in
Graham 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 Rainbow Trout are found in the project vicinity and in -stream work should be avoided
during the trout moratorium of January 1 to April 15 to minimize impacts to trout spawning.
The project site is on a largely forested parcel, and the development will involve 14 residential
lots, a road, and water and sewer line construction. Two sections of stream are proposed for
culverting — (1) one associated with the entrance road, which involves a 41-ft double-barreled
reinforced concrete pipe (RCP) culvert, and (2) the other associated with a construction entrance,
which involves 2 sections of single -barreled RCP culvert totaling 42 ft in length. Double
culverts set at the same elevation often result in one culvert carrying most or all of the flows over
time; this can cause channel instability and problems with aquatic organism passage. We
recommend replacing the double culverts with a spanning structure such as a bridge or
bottomless arch instead. If a culvert must be used, we recommend using a single larger squash
pipe capable of carrying base and stormflows. We also recommend against using RCP material,
as it is smooth and is less likely to hold stream substrate and provide for movement of aquatic
organisms like fish and salamanders.
Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]

Moose Br Development Page 2 February 18, 2020
UT Mauney Br, Graham County
As the culvert associated with the construction entrance appears to be needed only for
construction, we recommend removing this when construction is completed.
We offer the following recommendations for the project to minimize impacts to fish and wildlife
resources:
1. Work should be accomplished as quickly as possible and vigilance used in sediment and
erosion control during site preparation, construction, and clean up.
2. Any matting used on site should be free of nylon mesh; nylon mesh netting frequently
entangles wildlife and is slow to degrade, resulting in a hazard that may last for years.
3. We recommend against using RCP culverts, as RCP is smooth and is less likely to hold
stream substrate and provide for movement of aquatic organisms like fish and salamanders.
4. We recommend replacing the double culverts with a spanning structure such as a bridge or
bottomless arch instead. If a culvert must be used, we recommend using a single larger
squash pipe capable of carrying base and stormflows.
5. If at all possible, remove the culvert and restore the wetland impacts associated with
construction access.
6. Tall Fescue is listed as a temporary and permanent seed; this species is highly invasive and
should be avoided.
7. In -stream activities should be avoided between January 1 and April 15 in order to minimize
impacts to Rainbow Trout spawning.
8. The stream should not be excavated except in the immediate vicinity of the utility and road
crossing locations.
9. Manage stormwater from the site in order to mimic a hydrograph consistent with an
impervious coverage of less than 10%. Incorporate Low Impact Development (LID)
techniques in site design. Ensure that stormwater management controls temperature,
releasing cool water downstream.
10. Use non-invasive native species and LID technology in landscaping. Using native species
instead of ornamentals should reduce the need for water, fertilizers and pesticides. Using
LID technology in landscaping will not only help maintain the predevelopment hydrologic
regime, but also enhance the aesthetic and habitat value of the site.
11. We recommend maintaining undeveloped parts of the parcel as forested habitat and
conserving these areas as green space.
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: Jon Swaim, McGill Associates
Amy Annino, NC Division of Water Resources