20180110_Travis Wilson - NC Wildlife Resources Commission Comments (17BP bridges)_20170216

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� North Carolina Wildlife Resources Commission �
Gordon Myers, Executive Director
January 30, 2017
MEMORANDUM
TO:
FROM:
SUBJECT:
Caitlin Marks
NCDOT Division 3
Travis Wilson, Highway Project Coordinator
Habitat Conservation Program
Division 3 Bridge replacements
Biologists with the N. C. Wildlife Resources Commission (NCWRC) have reviewed the
information provided and have the following preliminary comments on the subject project. Our
comments are provided in accordance with provisions of the National Environmental Policy Act
(42 U.S.C. 4332(2)(c)) and the Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16
U.S.C. 661-667d).
Our standard recommendations for bridge replacement projects of this scope are as follows:
l. 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 blocic 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 ar entering into the stream.
4. If possible, bridge supports (bents) should not be placed in the stream.
5. If temporary access roads ar 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
Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]

PAGE 2 JANUARY 30, 2017
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 steam
underneath the bridge.
7. In trout waters, the N.C. Wildlife Resources 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, NCDOT biologist 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. 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.
11. 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.
12. 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.
13. 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.
14. 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.
15. 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.
If corrugated metal pipe arches, reinforced concrete pipes, or concrete box culverts are used:

PAGE 3 JANUARY 30, 2017
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(s)
should be placed on or near stream bankfull or floodplain bench elevation (similar to Lyonsfield
design). These should be reconnected to floodplain benches as appropriate. This may be
accomplished by utilizing sills on the upstream and downstream ends to restrict or divert flow to
the base flow barrel(s). Silled barrels should be filled with sediment so as not to entrap wildlife
or support mosquito breeding conditions. Sufficient water depth should be provided in the base
flow barrel(s) during low flows to accommodate fish movement. If culverts are longer than 40-
SO 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, base flow barrel(s) should provide a continuum of
water depth and channel width without substantial modiiications 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 ar 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 ar 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.
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. If the area reclaimed was previously wetlands, NCDOT should restore the area to
wetlands. If successful, the site may be utilized as mitigation for the subject project or other
projects in the watershed.
Project specific comments:
Replace Bridge No. 11 in Onslow County: We recommend replacing this bridge with a
bridge. Standard recommendations apply.
• Replace Bridge No. 13 in Onslow County: Grants Creek is designated as an Anadromous
Fish Spawning Area. NCDOT should follow all stream crossing guidelines for

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JANUARY 30, 2017
anadromous fish passage, including an in-water work moratorium from February 15 to
June 30. We recommend replacing this bridge with a bridge. Standard recommendations
apply.
• Replace Bridge No. 23 in Brunswick County: We recommend replacing this bridge with
a bridge. Standard recommendations apply.
• Replace Bridge No. 161 in Duplin County: We recommend replacing this bridge with a
bridge. Standard recommendations apply.
• Replace Bridge No. 219 in Duplin County: We recommend replacing this bridge with a
bridge. Standard recommendations apply.
• Replace Bridge No. 16 in Sampson County: We recommend replacing this bridge with a
bridge. Standard recommendations apply.
• Replace Bridge No. 252 in Sampson County: We recommend replacing this bridge with a
bridge. Standard recommendations apply.
If you need further assistance or information on NCWRC concerns regarding bridge
replacements, please contact me at [phone]. Thank you for the opportunity to review and
comment on this project.