HomeMy WebLinkAbout20200443 Ver 1_Request for IP_US ACE_20200402STATE OF NORTH CAROLINA
DEPARTMENT OF TRANSPORTATION
ROY COOPER
GOVERNOR
February 18, 2020
Kyle Barnes
Regulatory Project Manager
US Army Corps of Engineers
Wilmington District
Washington Field Office
Mr. Barnes,
JAMES H. TROGDON, III
SECRETARY
The North Carolina Department of Transportation (NCDOT) Ferry Division is requesting an
Individual Permit for dredging Sloop Channel. Although emergency conditions do not currently
exist, recent surveys have shown increased shoaling throughout the channel. The NC DOT is
looking to acquire the permits now so that in the event that shoaling does create emergency
conditions within the channel, a permit is already on hand. Due to the length of the channel and its
northward trajectory into the Pamlico Sound, two different dredging options will need to be
available for utilization. Therefore, the United States Army Corps of Engineers (USACE) would
assist NC DOT in areas where using a pipeline dredge is not feasible by employing a sidecast
dredge.
Sloop Channel runs from the Southdock Ferry Terminal to the naturally deeper part of the Pamlico
Sound, called The Reef, and is part of the Hatteras -Ocracoke ferry route. This route provides all
means of getting residents, visitors and supplies to and from Ocracoke Island and Hatteras. After
Hurricane Florence, the section of Sloop closest to The Reef experienced significant shoaling which
created navigational issues that prompted safety concerns for the Ferry Division, United States
Coast Guard (USGS) and general public. Additional shoaling was observed following Hurricane
Dorian in the same general area from around waypoint Sloop 5 to Sloop 8 in what has been
nicknamed the "dog -leg" because of how shoaling has forced the ferry route to run in zig zags. In
this approximately 3000-foot section only one vessel can travel through the channel at a time which
is not ideal from a safety or operational (ferry) standpoint. The USCG has expressed concern about
the narrowing of the channel in the same section and its vulnerability to becoming unnavigable for
day to day operations, including search and rescue missions. Being that this is a highly dynamic
area that is susceptible to winds and storm events, channel conditions could change rapidly. This
major modification to Major permit #224-87 will be for the NCDOT Ferry Division to 1) perform
maintenance dredging within Sloop Channel 2) excavate the channel to 225' wide and 12' deep
during dredging operations in order to match both the established channel and the terminal entrance
channel 3) dispose of dredged material into the state-owned Southdock spoil site located adjacent to
the ferry terminal using NC DOT's pipeline dredge 4) dispose of dredged material into the Pamlico
Sound using a US ACE sidecast dredge.
Mailing Address: Telephone: (252) 621-6251
NC DEPARTMENT OF TRANSPORTATION Customer Service: 1-877-368-4968
NCDOT FERRY DIVISION
159 LUCINDA LANE Website: www.ncdot.gov
POWELLS POINT, NC 27966
The purpose of this project is to be prepared to address the shoaling that resulted from Hurricane
Florence and Hurricane Dorian in the near future, and to keep a 10 year maintenance permit on
hand for the entirety of Sloop Channel so that emergency permits will not be needed at any point in
the future. Thus far, only surveying and general monitoring of conditions have been performed in
response to the shoaling. NCDOT has not dredged this location before but surveys suggest that the
changing conditions within the channel will result in the need for maintenance dredging. With the
maintenance permit we would be able to take care of all dredging needs quickly and efficiently to
get the route back to normal and under safe operating conditions without having to go through the
emergency permitting process. By excavating the channel to 225' wide and 12' deep during
dredging operations we would establish the channel as it is currently marked, match the entrance
channel width and depth, keep the channel from shoaling in as often, and reduce the amount of
dredging projects done in the area.
Sloop Channel stretches from its intersection with The Reef on its northern boundary to its
intersection with the ferry terminal entrance channel on its southern boundary. Due to shoaling,
channel conditions for vessel passage have begun to deteriorate. However, only the "dog -leg"
section of Sloop is currently presenting significant issues. It is believed that any and all dredging
that would occur in the near future would be located within this section. A vicinity map has been
included as part of the application.
The entrance channel to Sloop is permitted to a width of 225' and 12' deep MLLW. If we were to
dredge the entirety of the "dog -leg" section of Sloop to these dimensions based on the most recent
survey, we would remove approximately 126,423 cubic yards of material. The channel will always
be excavated while maintaining a 3:1 slope on all sides. There is no SAV present in the project area
due to water depth and the dynamic environment. Dredging activities will be limited to outside of
the moratorium period that spans from April 1 to September 30 each year. However, due to the
possibility of hurricanes and extreme shoaling, emergency situations could arise and dredging may
have to be done inside moratorium dates. Depending on the severity of shoaling in the channel,
dredging projects will last between three to twelve weeks.
The subsurface investigation included in this application was a preliminary study that was
performed in order to ensure that the material within the dog leg section of Sloop Channel was
suitable for offshore disposal if that method was ever needed. All of the samples were taken from
within the dog leg section where water depths are currently an issue. The offshore disposal option is
no longer being considered.
The type of dredge used for any necessary dredging events will be dictated by the location of
shoaling. If feasible, the NC DOT will use the Dredge Manteo which is a state-owned 12" pipeline
dredge that can transport excavated material approximately 2 miles to the Southdock spoil site.
Using the pipeline dredge is the most cost-effective and simplest method logistically because it is
state-owned and does not leave the North Carolina coast. If a pipeline dredge is utilized, it will be
located within the permitted channel at all times until the dredging event is complete. If the
compromised section of the channel exceeds the reach of the pipeline dredge (greater than 2 miles
from the Southdock spoil site), a US ACE sidecast dredge will be employed. If a sidecast is utilized
all material will be discharged directly into the Pamlico Sound and the dredge will either be moored
within the Hatteras ferry basin or working within the permitted channel. If emergency conditions
occur over 2 miles from the Southdock spoil site and a US ACE sidecast dredge is not available, it
is possible that the Ferry Division could look into employing a private contractor with a larger
pipeline dredge. In this scenario the privately -owned pipeline dredge would be able to reach further
distances than the state-owned dredge, but all disposal methods would remain the same.
Once permits are in hand the NC DOT will contact the NC DWR in order to get a MOA in place so
money can be transferred to the US ACE once it is determined that sidecast dredging in the dog leg
section of Sloop Channel is necessary.
If a pipeline dredge is utilized for any dredging event the Southdock spoil site will always be used
for material disposal. Current NPS SUP #5700-028 authorizes the NC DOT to place dredged
material via pipeline into the spoil site to maintain a 12' deep ferry channel. The permit also
authorizes that this spoil site can be expanded an additional .76 acres to accommodate additional
dredge material if needed. In accordance with this permit, the spoil site will be inspected by the
NPS resource management staff for any threatened and state species of concern prior to any
material being placed on the site.
Prior to submittal of this application the NC DOT sent a project narrative with drawings to US
FWS, NMFS, NC DMF, NC WRC and NC SHPO in order to receive input regarding the proposed
project. No concerns were raised by any of the agencies contacted and the e-mail correspondence
for each has been included as part of this application.
The equipment used for any dredging activities will include a sidecast or pipeline dredge, tug,
barge, excavator, bulldozer, 12" HDPE pipe and any other equipment needed for maintaining the
spoil site if applicable.
If you have any questions or need any additional information, please contact me.
Sincerely,
Brian Doliber
Environmental Specialist
Ferry Division
252 232 8025 mobile
252 6216251 office
bcdolibernncdot. gov
159 Lucinda Lane
Powells Point, NC 27966