20131279 Ver 3_DCM Minor Mod Request_20200317

From:
Coats, Heather
To:
Deaton, Anne; Dunn. Maria T.; Scarbrauah, Anthony; Pelletier. Josh R CIV CESAW CESAD (USA)
Cc:
Spivey. Kelly; Staples, Shane; Howell, Jonathan
Subject:
FW: [External] Dare County- Hatteras Inlet Permit Modification Request
Date:
Tuesday, March 17, 2020 2:02:07 PM
Attachments:
imaae001.Dna
Permit Modification Request to DCM.pdf
Hi everyone,
Please see Dare County's attached request to modify their permit to allow for dredging of Hatteras
Inlet using DOT's cutterhead dredge, with disposal to the adjacent DOT upland site, along with an
associated moratorium relief request to allow them to work through April. At this time, it's
estimated that the DOT dredge could start work in mid -April and they anticipate 3-4 weeks of
dredging is needed. According to the attached letter, work may also be conducted by the Corps'
dredge plant concurrently or shortly after pipeline dredging.
Channel width and depth are to remain at currently permitted dimensions and remain within the
authorized dredge corridor.
Please let me know if you have any questions, concerns or comments by March 31 or earlier, if
possible.
Thanks in advance and I hope everyone is staying safe and well!
Heather
Heather Coats
Beach & Inlet Management Project Coordinator
Division of Coastal Management
North Carolina Department of Environmental Quality
910 796 7302 office
heather.coats(2ncdenr.gov
127 Cardinal Drive Extension
Wilmington, NC 28405
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Brad Rosov [mailto:[e-mail]]
Sent: Saturday, March 14, 2020 1:54 PM
To: Coats, Heather <[e-mail]>
Cc: Ken Willson<[e-mail]>; Brent Johnson
<[e-mail]>
Subject: [External] Dare County- Hatteras Inlet Permit Modification Request

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Good afternoon Heather,
On behalf of Dare County, please see the attached request for the modification of their CAMA
Permit #129-16 allowing for maintenance dredging within Hatteras Inlet. As we've previously
discussed, the County is interested modifying the permit to allow for the use of a cutterhead
pipeline dredge with the disposal of the material at the NCDOT upland disposal site on the northeast
tip of Ocracoke Island during the month of April. On February 3, we submitted a letter requesting
relief from the dredge moratorium in April. This modification includes that request as well. Please
get in touch any time to discuss.
Regards,
Brad Rosov
Senior Marine Biologist/Project Manager
Main: 910-791-9494
Mobile: [phone]
brosov(@coastalprotectioneng.com
Coastal Protection Engineering
4038 Masonboro Loop Road
Wilmington, NC 28409

COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
4038 MASONBORO LOOP ROAD, WILMINGTON, NC 28409 910-791-9494 PHONE [phone] FAX
March 14, 2020
Heather Coats
Division of Coastal Management
North Carolina Department of Environmental Quality
127 Cardinal Drive Ext.
Wilmington, NC 28405-3845
Re: Minor Modification to the Hatteras Inlet Channel Maintenance Project (CAMA Major Permit #129-16)
Dear Ms. Coats:
As you are aware, the Division of Coastal Management (DCM) issued a CAMA Major Permit for the proposed
Hatteras Inlet Channel Maintenance Project on December 22, 2016. This permit was recently renewed on
January 22, 2020. As stated in the permit application, the purpose of the project is to maintain navigation from
sloop channel (AKA the Horseshoe) into the Hatteras Inlet gorge via a connector channel or what is known as the
South Ferry Channel. Maintaining navigation through this dynamic area is necessary for commercial and
recreational boats to enter the Atlantic Ocean through Hatteras Inlet. Without adequate accessibility into the
inlet, the local economy would have continued to be impacted. Since the issuance of the permit, Dare County
has sponsored a total of six (6) dredging events following the deep water within the permitted dredge corridor
to maintain navigability to the inlet gorge. A permit modification was issued on March 14, 2018 allowing for 1)
a one-time open water disposal of up to 500 cubic yards of material; and 2) to widen the permitted channel
width from 150' to 200'.
Several months ago, you informed us that the North Carolina Department of Transportation (NCDOT) was in the
planning stages of performing dredging operations in proximity of Hatteras Inlet utilizing a pipeline cutterhead
dredge in the near future (see the red polygon in Figure 1). NCDOT has performed multiple dredging events
using this dredge within the confines of Hatteras Inlet over the past several decades. Since learning about the
NCDOT's proposed dredging, Dare County and representatives of our firm have reached out directly to the
NCDOT to learn more about their plan and how their dredging activity may benefit Dare County's objective in
improving the navigability to the inlet gorge. During a call on March 5, 2020 with you and representatives from
NCDOT, Dare County, DCM, and our firm, we discussed the concept of using the NCDOT cutterhead pipeline
dredge to excavate a channel in a location most suited to clear and maintain a path through the shoals in the
South Ferry Channel which would benefit the navigation needs of Dare County while also achieving the NCDOT's
goal of piping approximately 60,000-80,000 cubic yards of material to an upland disposal site located on
Ocracoke Island (Figure 1). The NCDOT has granted permission for Dare County to utilize this upland disposal
site as stated in a letter dated March 13, 2020 (Attachment 1). Depending on the success of NCDOT's dredge
operation and scheduling, Dare County may perform additional maintenance dredging using a United Stated
Army Corps of Engineers (USACE) special purpose or sidecast dredge Dare County's intentions are to conduct
enough maintenance dredging of the channel to allow for dependable navigation through this area during the
upcoming fishing tournament season and into October, when Dare County could once again begin routine
maintenance of the South Ferry Channel under the existing permit. Because Dare County is currently permitted
to only use sidecast and special purpose dredges, DCM Staff stated that Dare County is required to modify their
existing permits to allow the proposed action.
4038 MASONBORO LOOP ROAD, WILMINGTON, NC 28409 • PHONE: [phone] • FAX [phone]
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.

This letter serves as Dare County's formal request to allow for a one-time event to utilize a cutterhead pipeline
dredge to dredge a channel 200' wide and to a depth of -12 ft. MLLW with disposal of dredge material at the
NCDOT upland disposal site on the north end of Ocracoke Island. The remainder of this letter is intended to
provide information required to make an informed decision on granting the requested permit modification.
Dredge Material
Disposal Site
i
� k-
6
D 1,0D0 2,0
Feet
Notes: Legend:
1. 2018 background =1 Proposed Pipeline Dredge Channel <7:) Nearshore Disposal Area
imagery is from the Q Previously Dredged NCDOT Channel " SAV
USDA's National p Proposed 2019 NCDOT Channel C3 Dredge Avoidance Areas
Agricultural n Hatters Inlet Permit 224-87
Imagery Program.
C3 NCDOT 2014 Channel
Permitted Dare County Channel Corridor
Figure 1. Location of the proposed pipeline dredge channel, historical NCDOT dredge footprints, and the upland disposal area.
4038 MASONBORO LOOP ROAD, WILMINGTON, NC 28409 • PHONE: [phone] • FAX [phone]
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.

Purpose for this Modification
The utilization of the NCDOT's cutterhead pipeline dredge to excavate a channel within the "Proposed Pipeline
Dredge Channel", as identified in Figure 1, and potentially supplemented by follow-up maintenance dredging
performed by the USACE's sidecast dredge, is intended to maintain navigability through the summer months.
This proposed maintenance plan is believed to have the most potential to minimize the need for prospective
emergency dredging later into the summer months when biological resources may be more sensitive to
dredging related activities. Beyond the economic benefits to the local economy as a result of maintaining
dependable navigation in this area, the proposed action is intended to curtail safety concerns for mariners. In a
letter dated March 12, 2020, in response to current conditions the United States Coast Guard (USGS) stated that
"the reduced channel depth (in South Ferry Channel) limits offshore access by surf -capable response assets from
USCG Station Hatteras Inlet and potentially extends their search and response times by more than two hours"
(Attachment 2).
Construction Schedule
Based on feedback from NCDOT, they could be available to start dredging starting around the second week of
April. They anticipate needing approximately 3-4 weeks of dredge time to satisfy their needs. Depending on the
condition of the channel and scheduling, Dare County may request the USACE to conduct supplemental dredging
using the sidecast Dredge Merritt in parallel or shortly after the completion of NCDOT operations.
Sediment Characterization
The material excavated by the NCDOT cutterhead pipeline dredge will be pumped to the upland site located on
the northeastern tip of Ocracoke Island where it will be temporarily stockpiled and used for NCDOT projects.
The USACE collected a series of vibracores in 2003 in order to characterize the material from within the Hatteras
Inlet complex. A total of 12 vibracores were collected and analyzed during this effort of which 4 were located
within the first channel that was dredged under this permit in the spring of 2017. Analysis of these four
vibracores revealed that the material was primarily composed of light gray to olive gray, poorly graded fine to
medium sands with trace shells having less than 5% silt. This material is designated as an "SP" soil type under
the Unified Soil Classification System (USCS). The results of laboratory testing showed the mean grain size of
the samples analyzed ranged from 0.22 mm to 0.33 mm and the silt content, defined as % passing the #200
sieve, ranged from 0.0% to 1.3%. The vibracore logs show the depths to the channel bottom at the boring
locations ranged from -5.0 ft. to -15.9 ft. below Mean Low Water (MLW) and extended to depths ranging from -
13.2 ft. to -21.9 ft. below MLW. In addition to the information provided by this geotechnical analysis, NCDOT
staff have stated that the material dredged by the NCDOT pipleline dredge and placed in the upland facility in
the past has been clean sand.
Impacts Associated with the Use of a Cutterhead Pipeline Dredge
When sediment re -suspension occurs as a result of dredging activity, larger particles rapidly settle out; however,
the finer sediments may remain suspended for longer periods, or even indefinitely in turbulent water (Adriaanse
and Coosen, 1991). Suspended particles may interfere with the biological functions of some organisms such as
feeding, respiration, reproduction and potentially cause predator avoidance. High turbidity and silt loads can
have detrimental impacts to filter feeding organisms associated with nearshore benthic communities including
amphipods, isopods, decapods, polychaetes, mollusks and others. The conditions of diminished light penetration
can detrimentally affect the photosynthetic activity of phytoplankton, the primary producers of energy
production. Additionally, turbidity can affect the health of submerged aquatic vegetation (SAV). These impacts,
however, are often realized mainly through the use of sidecast or special purpose dredging activity. Unlike
sidecaster and special purpose dredges, pipeline cutterhead dredges generate comparatively lower amounts
of suspended sediment plumes which are confined to within a few meters of the drilling cutterhead at the
4038 MASONBORO LOOP ROAD, WILMINGTON, NC 28409 • PHONE: [phone] • FAX [phone]
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.

seafloor. A pipeline dredge sucks dredged material through one end, the intake pipe, and then pushes it out the
discharge pipeline directly to the disposal site. They function by drilling below the surface of the substrate;
therefore, the sediment plumes created from the drilling cutterhead are generally highly localized (CSA et al.,
2009) compare to the impacts associated with sidecast or special purpose dredges. Additionally, the material is
hydraulically moved from the cutterhead /sediment interface directly into a pipeline, eliminating the hopper -
filling stage and associated overflow when hopper dredges are utilized. Because pipeline cutterhead dredges
create minimal sediment plumes compared to the other dredge types, turbidity -related impacts would be
minimized through the use of the pipeline dredge to conduct the majority of the dredge maintenance work for
this one-time event proposed to occur after March 31.
Operational differences between dredge types contribute to the differences in potential impacts to sea turtles.
Thus far, no incidental takes of sea turtles have been reported as a result of operations utilizing pipeline
cutterhead dredges operating in southeastern coastal channels (Dickerson et al., 2004). The relatively slow
dredging motion of pipeline dredges also presents minimal risk for sea turtle takes as a result of collisions.
Dredging within the Dredge Moratorium
The County's goal is to maintain safe navigation through Hatteras Inlet throughout the year. In order to do so,
since 2017, they have implemented two dredge events each year utilizing a sidecast or special purpose dredge.
These events have strategically been scheduled just prior to and just following the dredge moratorium in an
attempt to avoid the need to request relief for emergency dredging during the warmer summer months. Dare
County was well positioned to conduct a dredge maintenance event in October 2019 when the USACE and
Division of Water Resources (DWR) announced that the two agencies had allowed the MOU that allowed for the
USACE to conduct the dredging for this project to expire. By no fault of Dare County, the dredge event was
postponed until early January. By that time, shoaling in the channel had reached a critical level. Despite
dredging attempts by the Dredge Merritt between January 27 and February 12, the channel remained
significantly shoaled. Based on the most recent efforts by the USACE Dredge Merritt, it is unlikely that the
remaining budgeted sidecast dredging available would effectively clear the shoaling and render the channel
navigable.
Previously Obtained Authorizations
The NCDOT received a Department of Army Permit (Action ID #SAWCO-N-028-000318), a CAMA Major Permit
(#224-87), and a Special Use Permit issued by the National Park Service (NPS) (#5700-028) allowing for the
operation of a cutterhead pipeline dredge within a portion of Hatteras Inlet with the disposal of material at the
upland disposal facility located on the northeast corner of Ocracoke Island. They have obtained permit
modifications in the past allowing for similar dredge activities to occur in various areas within the inlet complex
(see Figure 1 above).
Dare County received a Department of Army Permit (Action ID #SAW-2011-02140) on March 1, 2017 and a
CAMA Major Permit (#129-16) on December 20, 2016 allowing for maintenance dredging to -12' MLLW within a
defined corridor utilizing the USACE's sidecast and special purpose dredge plants. Figure 1 shows the extent of
the permitted dredge corridor in which all of the six dredge maintenance events conducted by Dare County and
most of the pipeline dredging conducted by the NC DOT has occurred. Permit modifications to the Department
of Army and CAMA Major permits were made on August 29, 2017 and March 14, 2018, respectively allowing for
a wider (200') channel.
Collectively, the permits held by both entities (NCDOT and Dare County) allow for the proposed activities
included in this permit modification request. With that context, Dare County respectfully requests that you
4038 MASONBORO LOOP ROAD, WILMINGTON, NC 28409 • PHONE: [phone] • FAX [phone]
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.

expeditiously consider processing this permit modification such that the required planning and coordination
may be carried out in time to minimize any requests to dredge into the summertime months.
If you have any questions, please feel free to contact me directly at 910-352-1555.
Sincerely,
Brad Rosov
Senior Marine Biologist
Coastal Protection Engineering of North Carolina, LLC
Office: 910-791-9494
Mobile: [phone]
[e-mail]
CC
Brent Johnson, Dare County
Ken Willson, CPE-NC
4038 MASONBORO LOOP ROAD, WILMINGTON, NC 28409 • PHONE: [phone] • FAX [phone]
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.

Attachment 1: Letter from NCDOT

STATE OF NORTH CAROLINA
DEPARTMENT OF TRANSPORTATION
Roy COOPER
GOVERNOR
March 13', 2020
Mr. Brent Johnson
Dare County Project Manager
Dare County Grants and Waterways
P. O. Box 1000
Manteo, NC 27954
Mr. Johnson,
J. ERlc BoYET rE
SECRETARY
I have received your request to allow spoil from the proposed dredging activity for Dare County in
the vicinity of Hatteras Inlet for a one-time event that will be completed by the NCDOT Ferry
Division Dredge Manteo. This permission is granted to use the spoil site already permitted by the
National Park Service to allow the deposition of dredge material for this time only. Please let me
know if you have any questions. Thanks.
Sincerely,
C 0� Gl ,
Lance Winslow
Assistant Director of Marine Asset Management
Mailing Address: TELEPHONE: 252-62 ] -6250
NC DEPARTMENT OF TRANSPORTATION MOBILEPHONE: 252-333-7673
MARINE MAINTENANCE UNIT
159 LuCINDA LANE
POWELIS POINT, NC 27966

Attachment 2: Letter from US Coast Guard

U.S. Department c
Homeland Securii
United States
Coast Guard
Dare County Plaruling Dept.
Grants and Waterways Commission
kttn: Brent Johnson
P.O. Box 1000
Manteo, NC 27954
Dear Sir:
Commander
Sector North Carolina
721 Medical Center Drive
Wilmington, NC 28401
Phone: [phone]
Fax: [phone]
16670
March 12, 2020
Recent surveys indicate significant shoaling in Hatteras Inlet South Ferry Channel near Ocracoke
Island reducing the channel depth to three feet at mean low water. Consequently, this area has
become hazardous for commercial and recreational vessels transiting the area, preventing nearly
all vessel traffic from safely navigating this inlet. In addition, the reduced channel depth limits
offshore access by surf -capable response assets from USCG Station Hatteras Inlet and potentially
extends their search and rescue response times by more than two hours.
We greatly appreciate your consideration of the community impacts of the shoaling in the South
Ferry Channel in determining your dredging project resources and priorities.
Please contact the CDR Heather Nanning at [phone] if you have any questions.
Sincerely,