20191251_CAMA Additional Information Letter - Alternative Sandbags - Ocracoke_20200325

STATE OF NORTH CAROLINA
DEPARTMENT OF TRANSPORTATION
ROY COOPER
GOVERNOR
March 19, 2020
Greg Daisy
NC Division of Coastal Management
401 S. Griffin St., Ste. 300
Elizabeth City, NC 27909
J. ERIC BOYETTE
SECRETARY
Subject: CAMA Major Permit No. 24-03 Modification Request for Alternative Sandbags
Additional Information Response
Dear Mr. Daisey,
In response to your email dated March 5, 2020, the NC Department of Transportation is
providing additional information to the CAMA Permit No. 24-03 Modification request dated
March 2, 2020. NCDOT is currently installing sandbags along NC 12 on Ocracoke Island as
authorized by the Minor Modification (issued 1/31/2020) and will continue to install the
authorized traditional sandbags until the requested permit modification is issued or the project is
completed. Currently, the rate of production is approximately 30 linear feet a day.
The proposed alternative sandbags would not be hydraulically filled from the swash zone
as authorized for the current project. The proposed alternative sandbags would be filled from
onsite sources or the South Dock dredge spoil site using a front-end loader or similar equipment.
Onsite sources would be sand removed from the dune during sandbag installation or sand on the
roadway or roadway shoulders deposited by wind or overwash events. Sand for dune
reconstruction would be sourced from the South Dock Dredge spoil site or Avon borrow pit, all
as previously authorized by the Emergency Major Modification (issued 9/26/2019) and the Minor
Modification (issued 10/22/2019). Sand for the sandbags and dune reconstruction shall be of the
same general characteristics as the sand in the existing dune, per existing permit conditions. A
steel installation platform would be used to support the alternative sandbags during the filling
operation. Water may be used to pack the sand as the bags area filled to maximize capacity.
The alternative sandbags are made of white polypropylene and have a trapezoidal cross
section. The sandbag sections are 50 feet in length, and each 50' section is separated every 2' by
a sewn baffle. The 50' sections can be connected together at the ends with nylon strapping and
be cut to shorter sections. NCDOT proposes to use two rows of sandbags within the same
footprint of the previously authorized sandbags. The oceanward row would be 6' high and have
an 8'wide base. The landward row would be 4' high and have a 6' wide base. Both rows would
be placed 2' below the grade of the roadway and directly adjacent to each other with a combined
base of 14' wide. The alternative sandbags would be placed 10' from the edge of pavement and
would be entirely covered by the reconstructed dune. The reconstructed dune dimensions would
be 10' high and 50' wide, as previously authorized. The rate of installation for this sandbag
configuration would be approximately 200 feet per day. The proposed project is depicted on the
attached revised permit drawings.
Mailing Address:
NC DEPARTMENT OF TRANSPORTATION
DIVISION ONE
113 AIRPORT DRIVE, SUITE 100
EDENTON, NC 27932
Telephone: [phone]
Fax: [phone]
Customer Service: 1-877-368-4968
Website: www.ncdot.gov
Location:
113 AIRPORT DRIVE, SUITE 100
EDENTON, NC 27932

National Park Service coordination is currently underway. Their written response to the
project will be sent to you when received by NCDOT, but conversations with NPS indicate their
existing Special Use Permit would be amended to authorize the alternative sandbags upon
approval of the project by DCM. Correspondence with the US Fish and Wildlife Service and the
North Carolina Wildlife Resource Commission is complete. An updated Concurrence Letter
from USFWS will not be needed.
In addition to the question responses above, the location of the sandbags on Sheet 9 of the
permit drawings dated 12/4/2019 authorized by the Minor Modification (issued 1/31/2020) were
incorrectly depicted. The location of the 1,005 ft. section of sandbags on Sheet 9 needs to shift
southward approximately 200 linear feet on the drawing to better protect the roadway and avoid
damaging the established vegetative slope of the existing dune. Revised permit drawings have
been attached depicting this alignment shift.
These alternative sandbags would be a temporary measure until a long-term solution can
be selected and funded to maintain access to Ocracoke Island by NC 12. To minimize the
construction timeline of the temporary sandbag structure and to avoid impacts to open waters,
endangered species habitat, and environmentally sensitive areas, NCDOT requests CAMA Major
Permit No. 24-03 be modified to authorize the use of this alternative sandbag. Agency
correspondence, revised permit drawings, and additional product information are attached to this
letter. If you have any questions, please contact me at pcwilliams2kncdot. og_v or (252) 482-
1861.
Sincerely,
Jerry Jennings, P.E.
Division One Engineer
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Paul Williams
Division One Environmental Officer