20230780 Ver 2_Response to 6-09-23 additional information USACE & NPS DEA CALO Back Sound to Lookout BIght_NCWRC_20230706

� North Carolina Wildlife Resources Commission �
Cameron Ingram, Executive Director
MEMORANDUM
TO: John Policarpo
Wilmington District
US Army Corps of Engineers
and
Daniel Govom
NC Division of Coastal Management
NC Department of Environmental Quality
FROM: Maria T. Dunn, Coastal Coordinator
Habitat Conservation Division
DATE: June 20, 2023
SUBJECT: Response to Modification of Draft Environmental Assessment (Draft EA) Channel from
Back Sound to Lookout Bight Maintenance of the US Army Corps of Engineers and US
National Park Service Channels, Carteret County, North Carolina.
Biologists with the North Carolina Wildlife Resources Commission (NCWRC) have reviewed the
additional information and response to agency comments with regard to impacts on fish and wildlife
resources. Our comments are provided in accordance with provisions of the Coastal Area Management
Act (G.S. I I3A-100 through I I3A-128), as amended, Sections 401 and 404 of the Clean Water Act, as
amended, the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.), the Fish and
Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661 et seq.) and the Migratory Bird
Treaty Act.
The NCWRC previously reviewed and provided comments on the Draft EA Channel from Back Sound to
Lookout Bight Maintenance of the US Army Corps of Engineers (USACE) and US National Park Service
(NPS) Channels (Dunn 19 May 2023). Our previous comments on the Draft EA remain current. This
memo is in response to additional information received during a June 6, 2023 interagency meeting and a
June 9, 2023 revised federal consistency determination request.
The dredge proposals and deposition locations remain relatively unchanged from the original April 2023
Draft EA submittal. However, the USACE has determined the size of the island is no longer conducive to
using only heavy equipment and pushed berms to control dredge material effluent as originally presented
in the Draft EA. Specific information regarding the initial event and material placement on Sandbag
Island has been changed and expounded.
Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]

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The June 6, 2023 interagency meeting was called to specifically address material placement and
management on Sandbag Island. Two designs were presented, each using geotubes to direct and contain
material so it would not enter the water on the backside of the island where submerged aquatic vegetation
(SAV) is present. The use of geotubes was requested by USACE in lieu of sandbags. One design included
a temporary geotube dike installed within a small footprint along the back edge of the island. The other
design had a more robust structure footprint, using temporary geotube structures to encircle a larger area
of the island. Two types of geotube materials were discussed. The first geotube consisted of 100' sections
of burlap that was stated to biodegrade in a few years. The second geotube consisted of approximately 60'
sections composed of synthetic materials. USACE staff stated removal of geotubes once installed is
unlikely. In addition to geotubes, turbidity curtains would be installed around the entire project area.
Additional information requested of USACE during the call included specific design, design
justifications, cross -sectional plans, and constructability. The additional information was forwarded to
state agencies by USACE on June 9, 2023.
The NCWRC understands the need to dredge the USACE and NPS navigation channels and place
material in areas near dredged channel locations. We prefer beneficial placement of material for habitat
and public trust resource enhancement, management, or protection over mere sediment deposition.
Beneficial placement includes placement of material on managed bird islands, such as Sandbag and
Morgan Islands and in certain circumstances on Lighthouse Beach or Cape Lookout Oceanside Beach.
Placement of material in these areas should follow better management practices, such as moratoria,
natural design specifications, and construction methodology to minimize impacts to environmental
resources. These practices were detailed in the Draft EA and may be revisited prior to a placement event.
While we do not prefer side -cast dredging, the need to side -cast dredge to obtain deeper depths for
pipeline dredging or to obtain needed depths during urgency or emergency situations is an allowable
option. Implementation of moratoria and buffers should be included during side -cast dredge events. Due
to the options of upland placement and side -cast allowance, we do not prefer deep water placement. This
option has not previously been exercised and may impact several marine species and environments as
well as affect channel system hydrology.
The additional information received in June specifically addresses the initial dredge event and placement
of material on Sandbag Island. The USACE has determined the island is too small to allow control of
effluent placement utilizing only heavy equipment and pushed berms. The June 9, 2023 revised request
proposes to use synthetic geotubes, pushed berms, and turbidity curtains. The larger of the two footprints
presented during the June 6, 2023 meeting is proposed. The USACE states this design would provide
better stabilization and constructability. A 2' overburden is proposed to the geotubes.
The NCWRC is still concerned with the use of geotubes on Sandbag Island. We do not generally support
the use of sandbags or geotubes on shorelines due to the hardened environments they create and the
impediments they impose on wildlife resources. Even though they may be covered by overburden or even
planted after initial placement, the synthetic material remains for extended periods, as is evident by the
sandbags that still remain. Synthetic material, even when covered, can impede numerous wildlife
functions such as nesting, foraging, benthic recovery, and even island accessibility once overburden
erodes. However, we also understand the complications of control of effluent placement in an area with
minimal upland that is surrounded by sensitive aquatic environments. We believe impacts to SAV should
be avoided and expansion of the island should only be done to the previously stated parameters.
Therefore, the NCWRC does not object to the use of geotubes designed from the more natural, burlap
material that will biodegrade in a few years. This material will not remain indefinitely, but will allow
control of effluent placement, provide protection for SAV during material deposition, increase island
stability, and likely maintain a larger footprint for future placement events. The burial of the burlap
geotubes with overburden may also increase the life of the material in comparison to open exposure.

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The NCWRC appreciates the coordination among all agencies and interested parties to provide improved
accessibility and navigation safety in the Back Sound and Lookout Bight area. We strongly encourage
continued communication with our agency and the NPS with regard to material management activities
that may affect and improve waterbird and aquatic habitats. We look forward to any forthcoming
information and coordination as the initial project is implemented and the Final EA is presented. If there
are any comments, questions, or concerns please do not hesitate to contact me at
man a.dunn&ncwildlife.org or 252-495-5554.