HomeMy WebLinkAbout20211241 Ver 2_B-3186_B-5898 - Haywood County - NCWRC Comments_202307119 North Carolina Wildlife Resources Commission 9
Cameron Ingram, Executive Director
March 20, 2023
Patrick Breedlove
Division 14 PDEA Engineer
North Carolina Department of Transportation
253 Webster Road
Sylva, NC 285779
Subject Scoping Comments on Replacement of Bridge No.s 155, 158, and 168 over US 23/74/19,
Haywood County. B-5898 and B-3186
Dear Mr. Breedlove,
Division 14 of the North Carolina Department of Transportation (NCDOT) invited comments from the
North Carolina Wildlife Resources Commission (NCWRC) on the subject revised bridge replacement
project. NCWRC biologists are familiar with the wildlife resources in the area. The following comments
are offered to conserve wildlife resources affected by the project and to promote wildlife -based recreation
in accordance with the applicable provisions of the state and federal Environmental Policy Acts (G.S.
113A-1through 113-10; 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).
General Comments
NCWRC standard recommendations for bridge and culvert replacement projects of this scope include:
1. New bridges or other channel spanning structures are recommended over culverts because they
typically require minimal if any stream impacts. The clearances of bridges allow for human access
and wildlife passage, fish passage, and navigation by boaters. Unlike bridges, culverts can prove
difficult to dewater during construction, which can lead to extended periods of channel instability and
erosion.
2. Bridge deck drains should not discharge directly into streams.
3. Live concrete should not be allowed to contact water in or discharging to streams.
Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: (919) 707-0220 • Fax: (919) 707-0028
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Haywood County
4. If possible, bridge supports (bents) should not be placed in stream channels.
Applicable measures from the current NCDOT Erosion and Sediment Control Design and
Construction Manual should be implemented and maintained during construction. Matting used in
riparian areas should not contain nylon mesh because it entangles and kills wildlife. Coir matting
should be used on unstable stream banks that are steep or susceptible to high water and matting
should be securely anchored with wooden stakes according to NCDOT specifications.
6. Temporary detours and access roads should be designed and located to avoid wetland impacts, to
minimize clearing, and avoid destabilizing stream banks. Tree stumps and root mats should be left
where possible under and along temporary access roads to limit streambank disturbance and promote
regrowth of vegetation. Temporary fills should be removed to original ground elevations upon the
completion of the project. Disturbed areas should be seeded, or mulched, and native tree species
should be planted with a spacing of 10'x10'.
7. A clear strip of streambank (rip rap free) of 10 feet in width should remain on each side of the
channel underneath bridges to facilitate wildlife passage. Smaller widths are also beneficial where
there are narrow abutment setbacks. Alternatively, a "wildlife path" can be constructed with a top -
dressing of finer stone if full bank plating is required. These measures should also incorporate any
ditch line plating.
8. NCDOT biologists should be notified about streams that contain threatened or endangered species.
Special measures to protect these sensitive species may be required. NCDOT should also contact the
U.S. Fish and Wildlife Service for information on requirements of the Endangered Species Act as it
relates to the project.
9. All work in or adjacent to streams should be conducted in dry work areas. Sandbags, cofferdams, or
other clean diversion structures should be used where possible to avoid excavation in flowing water.
10. Heavy equipment should be operated from the banks rather than in stream channels to minimize
sedimentation and reduce the likelihood of introducing other pollutants into streams.
11. Only clean, sediment -free rock should be used as temporary fill (causeways) and fill material should
be removed with minimal disturbance of the natural stream bottom when construction is completed.
12. During geotechnical investigations, equipment should be inspected daily and maintained to prevent
contamination of surface waters from leaking fuels, lubricants, and hydraulic fluids.
The following recommendations apply to corrugated pipes, reinforced concrete pipes, or concrete box
culvert structures:
1. Culverts and pipes must be designed to allow for aquatic life passage in accordance with current
NCDOT Guidelines for Drainage Studies and Hydraulic Design. This typically includes burial of a
single low flow barrel at least 1 foot below the natural streambed and backfilling with native material.
If multiple barrels are required, then the high flow barrel(s) should be placed on or near a bankfull
elevation. These "flood" barrels should be reconnected to benches and include sills on the upstream
ends to restrict or divert base flow into the low barrel. Barrels with sills should be filled with
sediment to avoid standing water. If rip rap is used for backfilling, then it should also be topped with
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native or other finer material to facilitate wildlife passage. In accordance with NCDOT Guidelines
for Drainage Studies and Hydraulic Design, alternating or notched baffles should typically be
installed in base flow culverts that are steep or longer than 40-50 linear feet in a manner that mimics
the existing stream flow pattern and profile.
2. Riprap should be minimized on banks and avoided on streambeds except where bed scour may be
expected. Rip rap placed on the streambed should be embedded or "keyed -in" to prevent or shorten
the duration of subsurface streamflow.
3. If multiple pipes or cells are used, then at least one pipe or box should be designed to remain dry
during normal flows to allow for wildlife passage.
4. Culverts or pipes should be aligned with the existing channel alignment whenever possible. Channel
widening should be avoided. Stream channel widening at the inlet or outlet end of structures typically
decreases water velocity, disrupts aquatic life passage, and causes sediment deposition that requires
increased maintenance.
Replacement of the existing bridge or culvert in the same location with road closure is typically
recommended to minimize impacts. If road closure is not feasible, then a temporary detour should be
designed and located to avoid wetland impacts, minimize the need for clearing, and avoid destabilizing
stream banks. If the structure will be on a new alignment, then the old structure and the approach fills
should be removed from the 100-year floodplain. Approach fills should be removed down to the natural
ground elevation. The area should be stabilized with grass and planted with native tree species. NCDOT
should restore the area to wetlands if the area reclaimed was previously wetlands.
Project -Specific Comments
Adherence to the trout moratorium should not be necessary with this project. Lake Junaluska is a short
distance downstream of the site, and natural reproduction by trout is unlikely in this relatively short
stretch of Richland Creek.
Big brown bats (Eptesicus fuscus) have been documented roosting east of the project area in bridge no.
107 as well as in bridge no. 155. The project redesign may no longer require modification of bridge no.
107 over the railroad line. Gray bats (Myotis grisescens, US Endangered) have been documented roosting
in bridge no. 186 over Richland Creek upstream of the project bridges. Because of the concentrated bat
activity in the region, and elsewhere in the Pigeon River watershed, the NCWRC recommends that the
bridges be resurveyed for bats during the summer roosting season. Consultation with the U.S. Fish and
Wildlife Service should occur to update concurrence and conservation measures for the project, as
needed.
Wildlife passage under the existing bridges is likely limited, partly due to the urban environment, though
small mammals and reptiles likely move along the forested riparian areas of Richland Creek. The
greenway trail and rip rap -free floodplain benches allow for unobstructed wildlife passage now.
Therefore, in accordance with standard recommendations, we request that the rip rap -free benching be
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maintained under the new bridges. This accommodation may become more important to wildlife because
the new bridges are likely to be widened to accommodate future highway widening.
Please contact me at david.mchenryAncwildlife.org or (828) 476-1966 if you have any questions about
these comments or need additional assistance.
Cordially,
D PcHien�, NCWRC Western DOT Coordinator
cc: Susan Westberry, AICP, PWS, CPESC, AECOM
Lauren Wilson, U.S. Fish and Wildlife Service