Oregon Inlet Q3 2022 Maintenance Event Request DCM

COASTAL PROTECTION ENGINEERING OF NORTH CAROLINA, INC
4038 MASONaORo Loop ROAD
W I LM I NGTO N, NC 28409
910-399-1905
July 29, 2022
Heather Coats
Beach & Inlet Management Project Coordinator
North Carolina Division of Coastal Management
127 Cardinal Drive
Wilmington, NC 28405
Subject: Oregon Inlet Channel Maintenance Project —Written Notice of Intent to Conduct
Maintenance Dredging in Q3 of 2022 (Major Pennit #49-19)
Dear Ms. Coats:
The Division of Coastal Management (DCM) issued a CAMA Major Permit (#49-19) for the maintenance of
Oregon Inlet on June 24, 2019. This permit was subsequently modified on December 21, 2021 and has a
current expiration date of December 31, 2024. This letter serves as a written notice of Dare Counts intent to
initiate dredging under the subject pen -nit.
Dare County intends to utilize the dredge Miss Katie to maintain the Ocean Bar Channel at Oregon Inlet and
portions of the channel that run from Oregon Inlet to Hells Gate. Dredged material will be disposed in
proximity to the remaining portion of the Bonner Bridge and in the nearshore disposal area offshore Pea Island,
in accordance with the permits. Dredging is scheduled to commence in early to mid -August. Given the
frequent need for maintenance dredging at Oregon Inlet, Dare County anticipates the Miss Katie will perform
regular maintenance work under the subject permit for the foreseeable future. However, this correspondence
is specifically noticing for dredge operations anticipated to occur in August and September 2022 (Q3-2022).
The forthcoming dredge maintenance event is anticipated to be limited to dredging within the portions of the
Oregon Inlet Ocean Bar Channel and the Oregon Inlet to Hells Gate Channel as shown on the attached plans.
Dredging of the Ocean Bar Channel will follow best water as determined through coordination with the
USACE Wilmington District Navigation Branch. Dredging will be limited to a 400-foot-wide channel with
bottom elevation of -16 ft. MLW. Dredging of the Oregon Inlet to Hells Gate Channel will also follow best
water as determined through coordination with the USACE Wilmington District Navigation Branch and will
be limited to a 100-foot-wide channel with bottom elevation of -12 f . MLW. The disposal sites permitted
include a nearshore disposal site located off the northeastern end of Pea Island and disposal in proximity to the
deep scour holes beneath the Herbert C. Bonner Bridge. Because the majority of the existing Bonner Bridge
has been demolished, the Counts permit limits the disposal to the areas surrounding the remaining bridge
pilings which extends from the shoulder of Pea Island approximately 1,500 feet. This remaining portion of the
bridge is known as the "training structure". The training structure has been left in place to help keep the inlet
navigable after removal of the majority of the old bridge. The intention for keeping the training structure in
place is to forestall Davis Slough from returning to the prevailing deep -water channel through which it flowed
prior to the construction of the old bridge. The presence of the training structure, therefore, effectively serves
to minimize the risk that the deep -water channel will migrate south and threaten the integrity of the Pea Island
terminal groin. In 2008, the USACE wrote to the NCDOT that "the existing Bonner Bridge substructure acts
as a flow restrictor in Davis Slough and helps prevent the shifting of deep -water channels within the inlet".

Based on bathymetric surveys conducted by the USACE Wilmington District Navigation Branch on July 6 and
7, 2022, the estimated volume of material required to be removed to achieve the design channel dimensions for
the proposed Ocean Bar Channel and Oregon Inlet to Hells Gate Channel is 182,000 cubic yards and 194,000
cubic yards, respectively. Based on the current schedule of arrival for the Dredge Miss Katie and the estimated
dredging capacity, the maximum estimated volume of material that could be removed in August and September
is 182,000 cubic yards.
Permit Condition #5 of the CAMA Major Permit states, "Prior to the initiation of any dredging activities authorised by
this permit, the perittee shall, in coordination with the N.C. Department of Natural and Cultural Resources (DNCR�, develop
and i ple ent an archaeological survey of the proposed pr jea area. Initiation of permitted dredging activities shall not begin until
written approval is obtained from DNCR, and a copy of such approval has been submitted to the Division of Coastal
Management. "
Because this proposed maintenance event would occur in areas previously dredged by the USACE and/or
included in previous cultural resource investigations, Dare County and its consultants do not anticipate the
need for additional archaeological surveys prior to the Q3-2022 maintenance event. A letter has been sent to
the NC Division of Natural and Cultural Resources to request concurrence on this opinion and approval for
the proposed maintenance dredging. DCM will be provided a copy of NCDNCR's response to this letter,
should one be issued.
The subject maintenance dredging event will be the first dredging event to be performed with the newly
constructed dredge Miss Katie. In accordance with Permit Condition #7, Dare County is working with the
USACE regulatory project manager and EJE Dredging to determine a time and location for the USACE to
confirm the dredge has been constructed in accordance with the USACE hopper dredge plant specifications
and that the dredge plant complies with the conditions of t he Corps' 2004 FONSI. Please let me know if you
would like to participate in the inspection of the dredge.
As you are aware, a pre -construction conference has been scheduled for August 4, in accordance with Condition
#10 and a complete set of project plans is attached.
Please feel free to contact me anytime for further clarification or explanation of the project.
Very truly yours,
COASTAL PROTECTION ENGINEERING OF NORTH CAROLINA, INC.
Ken Willson
Project Manager
CC:
Robert Outten, Dare County
Barton Grover, Dare County
Josh Pelletier, USACE