20210694 Ver 1_WRC no moratorium comment on 57_HayB-6054AHarmonDenSC2020-08_20210518

North Carolina Wildlife Resources Commission
Gordon Myers, Executive Director

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

August 4, 2020

M E M O R A N D U M

TO: Dave McHenry, Division 14 Environmental Officer
North Carolina Department of Transportation

FROM: Marla Chambers, Western NCDOT Coordinator
Habitat Conservation Program, NCWRC

SUBJECT: Scoping review of NCDOT’s proposed replacement of Bridge No. 57 on I-40
over Cold Springs Creek, Haywood County. TIP No. B-6054A.

North Carolina Department of Transportation has requested comments from the North Carolina
Wildlife Resources Commission regarding impacts to fish and wildlife resources resulting from
the subject project. Staff biologists have reviewed the information provided. The following
preliminary comments are provided in accordance with the 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), as applicable.

Our standard recommendations for bridge replacement projects of this scope are as follows:

1. We generally prefer spanning structures. Spanning structures usually do not require work
within the stream and do not require stream channel realignment. The horizontal and
vertical clearances provided by bridges allows for human and wildlife passage beneath
the structure, does not block fish passage, and does not block navigation by canoeists and
boaters.

2. Bridge deck drains should not discharge directly into the stream.

3. Live concrete should not be allowed to contact the water in or entering into the stream.

B-6054A, BRG. 57, I-40
COLD SPRINGS CR., HAYWOOD CO. PAGE 2 AUGUST 4, 2020
4. If possible, bridge supports (bents) should not be placed in the stream.

5. If temporary access roads or detours are constructed, they should be removed back to
original ground elevations immediately upon the completion of the project. Disturbed
areas should be seeded or mulched to stabilize the soil and native tree species should be
planted with a spacing of not more than 10’x10’. If possible, when using temporary
structures the area should be cleared but not grubbed. Clearing the area with chain saws,
mowers, Bush Hogs, or other mechanized equipment and leaving the stumps and root mat
intact, allows the area to revegetate naturally and minimizes disturbed soil.

6. A clear bank (riprap free) area of at least 10 feet should remain on each side of the stream
underneath the bridge.

7. In trout waters, the Commission reviews all U.S. Army Corps of Engineers nationwide
and general ‘404’ permits. We have the option of requesting additional measures to
protect trout and trout habitat and we can recommend that the project require an
individual ‘404’ permit.

8. In streams that contain threatened or endangered species, Mr. Logan Williams with the
NCDOT - ONE should be notified. 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. In streams that are used by anadromous fish, the NCDOT official policy entitled “Stream
Crossing Guidelines for Anadromous Fish Passage” (May 12, 1997) should be followed.

10. In areas with significant fisheries for sunfish, seasonal exclusions may also be
recommended.

11. Sedimentation and erosion control measures sufficient to protect aquatic resources must
be implemented prior to any ground disturbing activities. Structures should be maintained
regularly, especially following rainfall events.

12. Temporary or permanent herbaceous vegetation should be planted on all bare soil within
15 days of ground disturbing activities to provide long-term erosion control.

13. All work in or adjacent to stream waters should be conducted in a dry work area. Sandbags,
rock berms, cofferdams, or other diversion structures should be used where possible to
prevent excavation in flowing water.

14. Heavy equipment should be operated from the bank rather than in stream channels in order to
minimize sedimentation and reduce the likelihood of introducing other pollutants into
streams.

B-6054A, BRG. 57, I-40
COLD SPRINGS CR., HAYWOOD CO. PAGE 3 AUGUST 4, 2020
15. Only clean, sediment-free rock should be used as temporary fill (causeways), and should be
removed without excessive disturbance of the natural stream bottom when construction is
completed.

16. During subsurface investigations, equipment should be inspected daily and maintained to
prevent contamination of surface waters from leaking fuels, lubricants, hydraulic fluids, or
other toxic materials.

17. If culvert installation is being considered, conduct subsurface investigations prior to structure
design to determine design options and constraints and to ensure that wildlife passage issues
are addressed.

If corrugated metal pipe arches, reinforced concrete pipes, or concrete box culverts are used:

1. The culvert must be designed to allow for aquatic life and fish passage. Generally, the
culvert or pipe invert should be buried at least 1 foot below the natural streambed
(measured from the natural thalweg depth). If multiple barrels are required, barrels other
than the base flow barrel should be placed on or near stream bankfull or flood plain bench
elevation (similar to Lyonsfield design). These should be reconnected to flood plain
benches as appropriate. This may be accomplished by utilizing sills on the upstream end
to restrict or divert flow to the base flow barrel. Silled barrels should be filled with
sediment so as not to cause noxious or mosquito breeding conditions. Sufficient water
depth should be provided in the base flow barrel during low flows to accommodate fish
movement. If culverts are longer than 40-50 linear feet, alternating or notched baffles
should be installed in a manner that mimics existing stream pattern. This should enhance
aquatic life passage: 1) by depositing sediments in the barrel, 2) by maintaining channel
depth and flow regimes and 3) by providing resting places for fish and other aquatic
organisms. In essence, the base flow barrel should provide a continuum of water depth
and channel width without substantial modifications of velocity.

2. If multiple pipes or cells are used, at least one pipe or box should be designed to remain
dry during normal flows to allow for wildlife passage.

3. Culverts or pipes should be situated along the existing channel alignment whenever
possible to avoid channel realignment. Widening the stream channel must be avoided.
Stream channel widening at the inlet or outlet end of structures typically decreases water
velocity causing sediment deposition that requires increased maintenance and disrupts
aquatic life passage.

4. Riprap should not be placed in the active thalweg channel or placed in the streambed in a
manner that precludes aquatic life passage. Bioengineering boulders or structures should
be professionally designed, sized, and installed.

In most cases, we prefer the replacement of the existing structure at the same location with road
closure. If road closure is not feasible, a temporary detour should be designed and located to
avoid wetland impacts, minimize the need for clearing and to avoid destabilizing stream banks.
B-6054A, BRG. 57, I-40
COLD SPRINGS CR., HAYWOOD CO. PAGE 4 AUGUST 4, 2020
If the structure will be on a new alignment, the old structure should be removed and the approach
fills 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. Tall fescue should not be used in riparian areas. If the area that is reclaimed was
previously wetlands, NCDOT should restore the area to wetlands. If successful, the site may be
used as wetland mitigation for the subject project or other projects in the watershed.

Project specific comments:

1. B-6054A, Haywood County, Bridge No. 57 on I-40 over Cold Springs Creek and Forest Service
Road 288. This project, also known as Harmon Den bridge, is one of five I-40 bridge
replacement projects in Haywood County that are the focus of the Pigeon River Gorge Wildlife
Connectivity Collaborative. This group of stakeholders is promoting wildlife connectivity and
reducing wildlife-vehicle collisions along I-40 in the Gorge. NCWRC staff have been involved
with this group, also known as Safe Passage, participating in meetings and field visits since
2017. We have reviewed the comment letters submitted by group members with expertise
including “Recommendations for Significantly Enhancing Wildlife Connectivity under Five
Interstate 40 Bridge Replacements in the Pigeon River Gorge, North Carolina” (Hillard et al
2019) and “Conceptual Plan Comments for Wildlife Passage Measures, NCDOT Bridge
Number 57 (Harmon Den) Replacement Project, Cold Springs Creek Interstate 40, Haywood
County” (Terry McGuire 2020). We largely agree with their recommendations regarding this
bridge replacement project.

The Harmon Den bridge project is arguably the most important of the five proposed I-40 bridge
replacements in the Pigeon River Gorge in terms of providing a safe crossing for wildlife. It is
surrounded by public lands, including Pisgah National Forest land to the east and west (both
sides of I-40). The Forest Service land to the east also serves as Harmon Den Wildlife
Management Area, a NCWRC Game Land, and a Black Bear Sanctuary. To the west, beyond the
Forest Service land, is the Great Smoky Mountain National Park. Wildlife connectivity research
is ongoing in the Pigeon River Gorge, using camera traps, roadkill reports, and GPS collared elk
movement data. The target wildlife species for the study and the Safe Passage group are large
mammals: black bear, elk and white-tailed deer. These animals have the potential for causing the
most harm in a wildlife-vehicle collision. We agree with this focus; but recommend that other
wildlife inhabiting the region be kept in consideration throughout the development of this
project.

As wildlife and human populations grow, the potential for conflict between them, including
vehicle collisions, also increases. Black bear numbers are significant in the project vicinity.
Ongoing research indicates that Bridge 57 is within a hot spot for wildlife mortality, especially
black bear, along I-40. Elk were re-introduced to North Carolina in the early 2000’s and the
current, slow-growing population is estimated to be between 150 and 200 individuals. Elk
activity is documented in the public lands both to the east and west of the project and one has
been observed crossing through the project along the secondary roadway (Forest Service Road
288). White-tailed deer occur throughout the state and make up the majority of vehicle-animal
collisions in North Carolina.

B-6054A, BRG. 57, I-40
COLD SPRINGS CR., HAYWOOD CO. PAGE 5 AUGUST 4, 2020
Cold Springs Creek joins the Pigeon River just downstream of the project. While trout may be
present in the project area, significant trout reproduction is not expected downstream, therefore
we are not requesting a trout moratorium for this project. The popular game fish, Smallmouth
Bass, also occurs in the vicinity. Maintaining aquatic life passage through the project area is
recommended to provide an important connection between the Pigeon River and the smaller
streams in the Cold Spring Creek watershed. This connection may be important for reproduction
of certain aquatic species and provides access to refugia from thermal pollution and other
potential dangers in the Pigeon River.

The existing project interchange includes two ramps that cross Cold Springs Creek with double-
barrel culverts, one on either side of I-40. Both culverts appear to split the base flow of the
stream into both barrels. Widening the stream flow beyond the natural stream width reduces
water depth, potentially restricting aquatic life movement through them. Splitting the flow also
increases the chances of debris jams blocking the culvert entrance, which can hinder terrestrial
and aquatic life passage and potentially destabilize the crossing structure. No dry passage is
provided for wildlife. Each barrel of the east culvert measures 8’6”H x 10’W and each barrel of
the west culvert is 6’10”H x 10’W. The target large mammal species require open crossings with
large openness ratios to successfully use the structure. The recommended opening size presented
by Hillard et al (2019), and well supported by literature, is 23 to 33 feet wide and 13 feet high.
The height and width of the openings of the ramp culverts carrying Cold Springs Creek fall
significantly short of the expert recommendations.

The conceptual plan for providing a crossing for wildlife to pass under I-40 in conjunction with
this bridge replacement project presented by NCDOT for review appears to direct wildlife along
Cold Springs Creek, either through the culverts under the ramps or across the ramps along a
widened shoulder of the secondary road (Forest Service Road 288). We agree that it is
appropriate to direct wildlife along a natural travel corridor, such as a stream valley. The
topography of the project region does appear to be a natural funnel along the Cold Springs Creek
valley leading to the Pigeon River. It seems very unlikely for the larger animals, especially elk,
to readily go through one culvert, under a bridge and then through another culvert in their travel,
especially culverts with the existing dimensions. It is unclear if reconstruction of the culverts to
an appropriate size for the larger wildlife is practicable, when considering the grade of the
existing road the ramps connect to. Wildlife choosing to cross over the ramps rather than through
culverts or directing them across the ramps or along a road shoulder is undesirable. Even though
the traffic volumes may be low, it would increase the chance of wildlife/vehicle collisions or
other accidents due to driver distraction when wildlife are present. Wildlife near the road will
necessitate additional measures, like fencing and cattle guards, to prevent them from entering the
roadways or other areas. The conceptual plan appears to allow wildlife access to the secondary
road.

Since significant changes to the ramp culverts are necessary in order to allow large mammal
passage through the project, we recommend a redesign of the interchange that removes the ramps
and culverts from the Cold Springs Creek side of the interchange. A partial cloverleaf design
should be investigated. With the ramps and culverts removed from the stream corridor, wildlife
will only have a bridge to cross under. Provided attention is paid to details of the crossing, such
as minimization of noise from traffic on the bridge and appropriate materials are used for the
B-6054A, BRG. 57, I-40
COLD SPRINGS CR., HAYWOOD CO. PAGE 6 AUGUST 4, 2020
travel path, the partial cloverleaf design with no ramps in the stream quadrants appears to have
the best chance for successful wildlife crossings.

Design elements for the fencing that will funnel wildlife to the crossing and prevent their access
to I-40 are important. Gaps in the fence should be avoided. Designs should not include elements
that increase the likelihood that wildlife will pass over (such as wooden fence posts), under
(fence not keyed into the ground), or around the fences (poor end fence designs). Appropriately
designed cattle guards and wildlife escape ramps, effective for both ungulates and bear, should
be used where appropriate. Terry McGuire’s comments provide detailed recommendations for
many aspects of the design for a more effective outcome. The desired pathway for wildlife to
travel should be natural ground and have natural elements, such as native vegetation, logs and
rocks, designed for small and large wildlife. Vegetation that invites wildlife, such as elk, to
linger and graze should not be used in areas close to the roadways or other areas where their
presence can cause problems, such as distracting drivers. Attractive vegetation could be used in
the visible distance to help lead the animals through the crossing. Riprap should be avoided in
the wildlife travel pathway. NCWRC routinely recommends a 10-foot wide, riprap-free level
path on each side of a waterway be incorporated for wildlife passage.

NCDOT has the benefit of the collective expertise of wildlife and road ecology professionals in
the Safe Passage group who are active in collecting data, raising funds, and making
recommendations for safe wildlife passage across I-40 in the Pigeon River Gorge. NCDOT
would do well to utilize these resources to maximize the probability of a successful wildlife
crossing on this first of five projects, likely the most important project in reducing
wildlife/vehicle accidents and improving wildlife connectivity in the Pigeon River Gorge.

We request that NCDOT routinely minimize adverse impacts to fish and wildlife resources in the
vicinity of bridge replacements. The NCDOT should install and maintain sedimentation control
measures throughout the life of the project and prevent wet concrete from contacting water in or
entering into these streams. Replacement of bridges with spanning structures of some type, as
opposed to pipe or box culverts, is recommended in most cases. Spanning structures allow
wildlife passage along streambanks, reducing habitat fragmentation and vehicle related mortality
at highway crossings.

If you need further assistance or information on NCWRC concerns regarding bridge
replacements, please contact me at [e-mail]. Thank you for the
opportunity to review and comment on this project.

cc: Lori Beckwith, USACE
Kevin Mitchell, NCDWR
Jeff Hunter, NPCA