20210303 Ver 1_17BP.14.R.159_DWR 20210203v1_Bridge 204_Macon_GP Application__NCWRC Comments_20230831

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]

August 31, 2023

Crystal Amschler
U.S. Army Corps of Engineers, Asheville Regulatory Field Office
151 Patton Avenue, Room 208
Asheville, NC 28801

Kevin Mitchell
NCDEQ, DWR
2090 U.S. Hwy. 70
Swannanoa, N.C. 28778

SUBJECT: Comments on GP/WQC Renewal Application for Replacement of Bridge 204 on SR
1533 over Walnut Creek, Macon County (17BP.14.R.159)
DWR 20210303 ver.1

Dear Mrs. Amschler and Mr. Mitchell,

The North Carolina Department of Transportation (NCDOT) applied for a renewal of a General 404
Permit and 401 Certification for the subject project. I reviewed the application but have been unable to
find any prior correspondence on the project from the North Carolina Wildlife Resources Commission
(NCWRC). In the absence of prior correspondence, the NCWRC offers the following comments on the
project to help conserve wildlife resources and to promote wildlife-based recreation in accordance with
applicable provisions of the state and federal Environmental Policy Acts (G.S. 113A-1through; 1 NCAC
25 and 42 U.S.C. 4332(2)(c), respectively), the Clean Water Act of 1977 (33 U.S.C. 466 et seq.), and the
Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d).

Bridge number 204 on 1533 over Walnut Creek (C Tr) is a timber deck on steel beam structure that will
be replaced with a 104’ long two barrel 12’x 6’ reinforced concrete box culvert on 1% slope. The culvert
will have inlet and outlet sills and floodplain benches.

17BP.14.R.159 Page 2 August 31, 2023
Macon County
Walnut Creek at the bridge supports naturally reproducing populations of Rainbow Trout (Onchorynchus
mykiss), and there are Brook Trout (Salvelinus fontinalis) in Ledford Branch which joins Walnut Creek
immediately downstream of the bridge. There also are rare aquatic species found well downstream of the
bridge in the Cullasaja River.

The NCWRC recognizes that road and drive alignments made replacement of the bridge with a modern
bridge impractical. And there is a large natural waterfall about 100 yards downstream of the bridge which
already prevents upstream passage by fish.

The culvert will have a low slope and should be passable to aquatic life if it retains sediment. To promote
this, the NCWRC requests that the culvert be backfilled with a rip rap underlayment and topping of
relatively clean natural rock and gravel, which may be available on-site. If the culvert is not backfilled or
does not accumulate sediment, then, based on slope, the stream in the upper portion would likely be
overly shallow or sheet flow. The NCDOT typically backfills bridge to culvert projects like this,
particularly those in trout streams, but I did not see (but may have missed) specific reference to
backfilling in the design plans. Material quantities in the NCDOT contract might need adjustment if
backfilling wasn’t planned for but is added.

The NCWRC requests that the following conditions be included in authorizations to minimize impacts of
the project on trout resources and fishing:
1. The culvert should be backfilled with a rip rap underlayment and topping of relatively clean
natural rock and gravel.
2. The January 1 to April 15 trout moratorium will be followed since construction has a reasonable
potential to cause inadvertent sedimentation in trout spawning habitat downstream of the bridge.
3. Applicable measures from the current NCDOT Erosion and Sediment Control Design and
Construction Manual should be adhered to. Design Standards in Sensitive Waters (15A NCAC
04B .0124) are recommended as practical in the project’s erosion control design because a
watershed with sensitive species will be affected. Subpart D of the rule describes measures that
can apply to bridge replacement projects where sediment basins are not needed, or practical.
4. In accordance with standard GC conditions, matting used in riparian areas should not contain
nylon mesh because it entangles and kills wildlife. Coir matting should be used on disturbed
stream banks that are steep or susceptible to high water. Matting should be anchored with
wooden stakes according to NCDOT specifications.
5. Heavy equipment needs to be well-maintained and concrete pouring needs to be closely
monitored to avoid and quickly mitigate fuel, fluid, or wet concrete losses in or near streams.
6. Removal of vegetation in riparian areas and wetlands should be minimized.
7. Sandbags, rock berms, cofferdams, or other adequately designed diversion structures should be
used where excavation or other periods of extended stream disturbance has the potential for
downstream sedimentation.
17BP.14.R.159 Page 3 August 31, 2023
Macon County
8. The natural dimension, pattern, and profiles of streams and the grades of wetlands should be
restored where temporarily impacted.

Thank you for the opportunity to review and provide recommendations on this project. Please contact me
at [e-mail] or [phone] if you have any questions about these comments.

Cordially,

Dave McHenry, NCWRC Western DOT Coordinator

cc: Patrick Breedlove, NCDOT Division 14 PDEA Engineer