Buxton NC - Project Narrative

BEACH RENOURISHMENT TO PROTECT NC HIGHWAY 12 AT BUXTON
COUNTY OF DARE, NORTH CAROLINA
NARRATIVE DESCRIPTION OF PROJECT
Dare County (NC), as the Applicant, is proposing a beach renourishment project, which calls for
up to 1.2 million cubic yards (cy) of beach -quality sand to be pumped onto the 2.9-mile (15,500
linear feet) beach via offshore dredging scheduled to start the summer of 2022. The anticipated
average fill density (volume of nourishment per linear foot of beach) is -77 cubic yards per linear
foot (cy/lf) of shoreline. The project's purpose is to restore sand losses due to chronic erosion and
to replenish the additional volume loss due to hurricanes Florence (September 2018) and Dorian
(September 2019).
The Applicant and its authorized Engineer (Coastal Science & Engineering) had the official pre -
application meetings on 7 November 2019 with federal and state agencies in addition to other
individual meetings with resource agencies. The sign -in sheet is included herein as Attachment 1.
Initial guidance regarding the preparation of environmental documents required by state and
federal resource agencies before, during, or after construction was received from the meeting. The
Applicant also requested Section 7 consultation under the Endangered Species Act at the earliest
time, along with instructions regarding endangered species monitoring requirements during
construction, and environmental sampling, if necessary, before and after construction
The Applicant has submitted the DWR Pre -Filing Meeting Request Form on 14 June 2021 per the
Clean Water Act Section 401 Certification Rule (Attachment 2).
• The project proponent hereby certifies that all information contained herein is true,
accurate, and complete to the best of my knowledge and belief.
• The project proponent hereby requests that the certifying authority review and take
action on this CWA 401 certification request within the applicable reasonable period
of time.
Coastal Science & Engineering 1 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

INTRODUCTION
Dare County encompasses -89 miles of ocean shoreline from the Town of Duck to Hatteras Inlet.
The northern 30 miles (on Bodie Island) include (from north to south) the towns of Duck, Southern
Shores, Kitty Hawk, Kill Devil Hills, and Nags Head. There is a 5-mile undeveloped portion of Cape
Hatteras National Seashore (Seashore) at the southern end of Bodie Island. The southern -53 miles
on Hatteras Island encompass the National Seashore and the communities of Rodanthe, Salvo,
Avon, Buxton (the proposed project site), Frisco, and Hatteras (Figure 1). Approximately 16 miles
are developed, and 38 miles are undeveloped along the oceanfront. In total, 50 percent of Dare
County's ocean shoreline is developed, and 50 percent is undeveloped and held in permanent trust
by the Seashore.
The narrative for the proposed Buxton beach renourishment project includes the following sections:
Review of the 2017-2018 Beach Restoration Project........................................................... 2
Summary of the 2017-2018 Project Performance............................................................... 5
ALTERNATIVES................................................................................................................. 7
PROJECT DESCRIPTION.................................................................................................... 7
SEDIMENT QUALITYAND COMPATIBILITY...........................................................................8
(1) Beach Sampling..................................................................................................................8
(2) Offshore Borrow Area Sediment Quality and Compatibility Analysis ............................9
CULTURAL RESOURCES STUDY IN THE BORROW AREA ....................................................... 10
DUNE MANAGEMENT PLAN.............................................................................................. 10
METHODS OF CONSTRUCTION......................................................................................... 11
SUPPLEMENTARY REPORTS...........................................................................................113
REFERENCES CITED........................................................................................................ 13
FIGURES........................................................................................................................ 14
ATTACHMENT 1 (Scoping Meeting Sign -Up Sheet)............................................................. 25
ATTACHMENT 2 (DWR Request Form for 401 Certificate)................................................... 26
ATTACHMENT 3 (15A NCAC 07H.0312 - Effective 1 April 2021)............................................. 28
Coastal Science & Engineering 2 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Dare County, as the Applicant, proposes to place up to 1.2 million cubic yards (cvl of beach -quality
sand along a 15,500-foot (-2.9-mile) length of Hatteras Island in the National Seashore, including
-0.8 mile in front of the developed Village of Buxton (Figure 2). The average fill density is -77 cubic
yards per foot (cy/ft). Nourishment sand will be excavated from a -200 acre offshore borrow area
located -2 miles offshore of Buxton within state waters. Confirmed by sixteen reconnaissance
vibracores and the final ten 10-ft long vibracores in the proposed borrow area, the Applicant
proposes an excavation depth of 10 feet below the existing substrate. The proposed borrow
area contains approximately 3.3 million cubic yards of beach -quality sand (if 10 ft excavation depth
is permitted). Cultural resource and geophysical surveys have been conducted to ensure no
impacts on culturally significant sites, other protected resources, or hard bottom in the proposed
borrow area.
The proposed renourishment project will serve five primary purposes:
1) Replenish sand losses due to chronic erosion, hurricanes (particularly hurricanes
Florence in September 2018 and Dorian in September 2019), and winter storms since
the completion of the 2017-2018 beach restoration project.
2) Continue to protect North Carolina State Highway 12 (NC 12) by providing a wider
beach to buffer storm waves between the ocean and the highway. NC 12 is the only
highway along Hatteras Island, serving permanent residents, first responders,
vacationers, and sightseers.
3) Further augment the regional supply of beach sand by utilizing a non -littoral borrow
source of compatible sediments from an offshore borrow area.
4) Integrate a dune management plan into the renourishment design to improve storm
protection.
5) Maintain Dare County's eligibility for future FEMA community assistance funds.
Review of the 2017-2018 Beach Restoration Project
An initial beach nourishment project was completed between 21 June 2017 and 27 February 2018
along the same stretch of oceanfront as the proposed renourishment project to meet the urgent
erosion problem in that area. Approximately 2.6 million cubic yards of beach -quality sand was
excavated from an offshore borrow area and placed along the 2.9-mile shoreline. The 2017-2018
offshore borrow area is adjacent to the proposed new borrow area and located within the state
waters, as illustrated in Figure 2. The permitted excavation depth was up to 7 ft below the existing
substrate. Dare County sponsored this project and served as project owner and administrator. The
Coastal Science & Engineering 3 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

County used local funding for the project without imposing additional costs on the state of North
Carolina or the US Government.
The County commissioned a feasibility study to assess erosion and formulate solutions (CSE 2013)
and subsequently completed an environmental assessment of beach restoration alternatives and
potential impacts (USACE-USDOI-NPS 2015). The County used official long-term erosion rates
published by NCDENR (2012) and determined the rates along different sections of the project area.
The average annual erosion rate adopted for the 2017-2018 project was 114,500 cy per year
(ie - 9,542 cy per month) along the 15,500-ft project area.
Dare County obtained permits under the National Environmental Policy Act (NEPA) and the state
Coastal Area Management Act (CAMA) permitting process, and procured the following state and
federal permits and certification:
1. North Carolina Department of Environment Quality 401 Water Quality
Certification (DWR #15-1087) - Issued on 23 November 2015.
2. North Carolina Department of Environment Quality Major CAMA Permit
(#136-15) - Issued on 15 December 2015.
3. National Park Service Special Use Permit (GOV16-5700-014) - Issued on 11
March 2016 and revised on 27 November 2017 for an extension.
4. U.S. Army Corps of Engineers (USACE), Department of the Army Permit
(#SAW 2015-01612) - Issued on 24 March 2016.
On behalf of the County, CSE prepared a final design, plans, specifications, and bid documents and
made them available to contractors on 15 March 2016 following review by County officials. The
County's reserved construction budget was $22,963,175. Bids were received and opened at 2 pm
on 7Apri12016. Because work involved excavations offshore, ocean -certified dredges were required
under US Coast Guard regulations. Therefore, only five US dredging firms were qualified to perform
this work. Four (out of five) firms, having ocean -certified equipment, bid on the project: Dutra
Group (Dutra), Great Lakes Dredge & Dock Company (GLDD), Manson Construction, and Weeks
Marine. Two construction windows were considered in the bid structure: summer 2016 and summer
2017.
Weeks Marine offered the lowest bid for construction in summer 2017, equating to $22,150,000
(included mobilization/demobilization and pumping) for the maximum volume allowed under the
permits of 2.6 million cubic yards. The net price equated to approximately $8.52 per cubic yard
($/cy). This bid price was $813,175 below the County's budget. The remaining funds could be used
Coastal Science & Engineering 4 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

for post -project monitoring, sand fencing, legal fees, administration, and future renourishment
study. Weeks Marine was awarded the contract in May 2016 to conduct the 2.6 million cubic yard
project in summer 2017.
Summer dredging was permitted for beach nourishment projects in the northern Outer Banks
because of inclement wave conditions in the winter months. The Contractor (Weeks Marine) elected
to use a cutterhead dredge (CR McCaskill) to start the nourishment on 21 June 2017. Construction
lagged primarily due to rough sea conditions that frequently curtailed operations and led to
mechanical breakdowns. As of 22 August 2017, -1.1 million cy of sand (-42 percent of the total
contract volume) were placed on the beach by the CR McCaskill.
In September 2017, four named hurricanes (Irma, Jose, Katia, and Maria) impacted the project area,
producing wave heights significantly higher than the required safe operating conditions for a
cutterhead dredge. Construction had to cease for over 50 days until 11 October, when the
Contractor started to use a hopper dredge (RN Weeks). Despite the intermittent work schedule,
construction moved forward. As of 22 December 2017, nourishment in front of the narrow isthmus
of NC Highway 12 was completed, and the highly vulnerable section of the road was protected.
Weeks Marine's newly constructed hopper dredge, the Magdalen, passed sea trials and obtained
the operation certificatejust in time in January2018, when the project was-80 percent completed.
With twice the the capacity of the RN Weeks, the Magdalen finished the last -0.5 million cy of work.
She delivered her last load at 1:30 pm on 27 February 2018, almost 5 months later than the
Contractor's original schedule. The three dredges that the Contractor used are shown in Figure 3,
and the Contractor's production rates in relation to the offshore wave heights" are summarized in
Figures 4 and 5. The average daily production rate was-18,000 cy per day (cy/day) during the
summer months of June through August, whereas the average daily production rate in the fall and
winter months of September through February was only -8,000 cy/day.
[*Wave records were obtained from a wave buoy at Diamond Shoals at NOAA National Data
Buoy Center - NDBC Station 41025. It is approximately 16 miles southeast of Buxton and
appears to be the closest real-time wave buoy to the Buxton project site. The station is
located at a water depth of -225 ft.]
Despite all the delays, the project was completed without any sea turtle takes or any other
environmental incidents. Collaborations among the Owner (Dare County), regulatory agencies
(USACE, NIPS, and NCDEQ), and the Contractor remained excellent during construction. The Buxton
project holds implications for future renourishment work. If summer dredging had not been
permitted, the duration of construction could have been longer, and the road could have breached
again during hurricanes and storms.
Coastal Science & Engineering 5 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Summary of the 2017-2018 Project Performance
After project completion, the newly nourished beach withstood a series of nor'easters in March 2018,
Hurricanes Florence in September 2018 and Dorian in September 2019, and other winter storms
without much interruption of the passage of NC Highway 12 or damage to the Buxton oceanfront
properties. However, nourishment sand was lost outside of the project area beyond the depth of
closure* after each weather event since project completion.
(*The normal limit of significant change in bottom elevation is called "depth of closure* - DOC.
For the Buxton project area, DOC was determined to be —24 ft NAVD (USACE-USDOI-NPS 2015).
This depth is based on estimates of DOC at decadal scales at Duck (Birkemeier 1985), Bogue
Banks (Olsen 2006), and Nags Head (Kaczkowski & Kano 2012). Therefore, the calculation limit
of sand volumes is referenced from foredune to —24 ft NAVD unless specified otherwise.]
Total volumes along the Buxton project area (relative to the pre -project condition in May 2017) are
illustrated in Figure 6. The pre -hurricane season beach condition survey in June 2018 and post -
Hurricane Florence survey in October 2018 show that the net sand volume loss due to Hurricane
Florence is 303,732 cy** along the 15,500-foot project area within the calculation limit from
foredune to -24 ft NAVD. This sand loss is equivalent to -12 percent of the volume placed during
the 2017-2018 project. The pre -hurricane season beach condition survey in June 2019 and post -
Hurricane Dorian survey in November 2019 show that 164,690 cy of sand (-6 percent of the
nourishment volume) shifted out of the project area.
(**To isolate incident -related damage, volume losses between surveys were adjusted above (but
not in Figure 6) for background erosion that was predicted to occur during the time period
between the pre -storm (June 2018) and post -storm (October 2018) surveys. The annual
background erosion was estimated to be 114,500 cy per year (cy/yr) (USACE-USDOI-NPS 2015).
This is equal to 9,542 cy per month. During the four -month period between the pre- and post -
storm surveys, background erosion was estimated to be 38,168 cy. Therefore, the net sand
volume loss due to Hurricane Florence is 303,732 cy along the 15,500-foot project area between
the foredune and the FEMA depth limit.]
Confirmed by the most recent beach condition survey in August 2020, approximately 634,925 cy (the
orange bar on the far right in Figure 6) of the 2.6 million cubic yard nourishment sand remained in
the project area, which is equivalent to -25% of the volume placed during the 2017-2018 project.
Sand loss along the Village of Buxton was greater than along the National Seashore. Ninety-seven
percent (97%) of nourishment sand placed along the Village of Buxton was lost (represented by the
first group of bars in Figure 6). In comparison, the project lost 65 percent and retained 35 percent of
the sand volume placed alongthe National Seashore. Surveys of the-5,000-ft downcoast area (Cape
Point east shoreline) since nourishment indicate that as much as 480,000 cy (or -50 percent) of the
Coastal Science & Engineering 6 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Buxton sand losses have accreted to built-up the undeveloped beach of the National Seashore.
This is equivalent to an accretion of 96 cy/ft (or -38 cy/ft/yr).
By August 2020, beach conditions at Reach 1 - Buxton returned to the pre -nourishment condition
of May 2017 in regards to the unit volume, as shown in Figure 7. The red line in Figure 7 represents
the pre -nourishment condition in May 2017, and the black line represents the most recent
condition in August 2020. The section of beach where the black line overlaps with the red line or
below the red line (ie - stations 1885+00 to 1930+00 in the Village of Buxton) means there was less
sand volume along that section in 2020 than in 2017.
The annual erosion rate since project completion (between February 2018 and August 2020) is
between 650,000 and 700,000 cy/yr (over 50 cy/ft/yr), which is several times higher than the
historical average adopted for the design of the 2017-2018 project (114,500 cy/yr or 7.4 cy/ft/yr). A
high erosion rate has also been measured at Nags Head (Dare County) in recent years. Nags Head
is located -45 miles northeast of Buxton in the northern Outer Banks. CSE's beach condition surveys
show that the average annual erosion rate at Nags Head has been over 45 cy/ft/yr between
November 2017 and April 2019. That is much higher than its historical erosion rate of 5.2 cy/ft/yr.
Several factors caused the much -higher -than -normal erosion rate along the Buxton project area,
listed as follows.
(1) Normal nourishment sand spreading at the project boundaries
(2) Four named hurricanes (Irma, Jose, Katia, and Maria) impacted the project area
in September 2017 during construction, increasing the sand deficit relative to
pre -construction conditions.
(3) A series of nor'easters impacted the project area in March 2018, soon after project
completion
(4) Hurricanes Florence (September 2018) and Dorian (September 2019) impacted after
project completion
(5) Sand shifted offshore beyond -24 ft NAVD due to the existence of a nearshore deep trough
(6) Deterioration of sand -retaining structures (ie -groins) at the south end of the project has
lessened sand trapping
The loss of function of the existing groins was discussed in the Environmental Assessment for the
project (USACE-USDOI-NPS 2015) but was not evaluated further because new groins are not
allowed along the northern Outer Banks under NC state Coastal Zone Management rules and
regulations. Due to the rapid loss of nourishment volume in recent years, CSE recommended in
2019 that the groin conditions should be studied in greater detail while planning the
Coastal Science & Engineering 7 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

renourishment project. The initial inspection conducted by CSE in July 2019 shows that if the
landward underground portion is not included in the equation, less than 50 percent ofthe existing
groin structure remained in the site. Therefore, the repair or restoration work of the groins would
be considered as construction of a "new groin," which is currently not permittable for the Buxton
area.
Oblique aerial photos in Figure 8 were taken on 15 April 2021. These photos show that there was
little dry -sand beach along the Village of Buxton, some sand bags were re -exposed due to erosion,
and new sand bags were installed by property owners along the oceanfront as a temporary
shoreline protection measure. The loss of dry beach has made NC Highway 12 vulnerable to
flooding and breaching, once again.
ALTERNATIVES
Three alternatives have been evaluated for the proposed beach renourishment (similarto the initial
2017-2018 Buxton beach restoration project):
• Alternative 1- No -Action
• Alternative 2 - Renourishment with Offshore Sand Source and Winter Construction
• Alternative 3 - Renourishment with Offshore Sand Source and Summer Construction
Additional alternatives were initially considered during the early stages of planning for the 2017-
2018 project as well as the proposed renourishment project, but were dismissed for environmental,
geological, technical, or economic reasons (USACE-USDOI-NPS 2015; CSE 2019).
Construction during the summer months is necessary in this setting because of high wave conditions
for the remainder of the year, as shown in the initial 2017-2018 project. The full scope of work
proposed under Alternative 3 would best continue to protect NC 12 and National Park Service facilities
at Cape Hatteras. It would increase the area of sea turtle and shorebird nesting habitat, and it would
also reduce the frequency of future remedial or emergency measures. The short-term biological
impacts to benthic organisms under Alternative 3 may be greater than Alternative 2. However,
Alternative 2 would require work in the winter months, placing Contractor personnel at much greater
risk due to unsafe conditions offshore. Therefore, Alternative 3 is the Applicant's preferred alternative.
Further, this is consistent with all previous nourishment events on Dare County beaches since 2011.
PROJECT DESCRIPTION
The proposed project (Alternative 3) will involve excavating beach -quality sand from an offshore
borrow area near Buxton Village via hydraulic and/or hopper dredge (see Fig 2). Borrow sediment
will be pumped to the beach and spread by land -based equipment (eg - bulldozers) in the beach
Coastal Science & Engineering g Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

zone between the toe of dune/mid-dry sand beach and the low watermark. The elevation of the
nourishment berm will be set at or below the normal dry -beach level (approximately+7 feet NAVD)
so that it is naturally overtopped by waves during minor storms. The nourishment profile will be
designed to adjust rapidly to changing wave conditions with an expected gradual shift of sand into
deeper water as the profile equilibrates. Backshore areas are expected to be enhanced gradually
after construction by natural dune building processes.
The project, as shown in Figure 2, is located at Cape Hatteras National Seashore. The southern -4,500
ft of the project (Reach 1) fronts the developed oceanfront of the Village of Buxton. The maximum
nourishment volume will be 1.2 million cubic yards, and the average maximum fill density (volume
of nourishment per linear foot of beach) will be -77 cubic yards per foot (cy/ft). This is equivalent to
an average beach width increase after natural profile adjustment of -45 ft in the Cape Hatteras area
and 120 ft in Buxton. During construction for a 2.9-mile-long project, the anticipated maximum
impact area is -142 acres. The maximum project is expected to create -18 acres of new dry -beach
habitat. This expanded dry -beach area will eventually produce -4.5 acres of new dune habitat via
natural processes after the equipment is removed from the beach. The maximum scale is expected
to provide approximately three years of erosion relief, dune growth, and NC 12 protection under
normal conditions. The final project volume will be determined according to the state and federal
permits, the County's construction fund, and the responsible bid.
Fill densities will vary from 40 cy/ft in Reach 2 - National Seashore to 180 cy/ft in Reach 1- Buxton to
best achieve the Applicant's purpose and goals of the proposed renourishment project. Figure 9
includes the fill design of two representative stations, and the details of the design are illustrated in
Permit Drawing Sheets 03-12. The elevation of the dry -sand berm is set to be at+7 ft NAVD, and the
initial dunes will be constructed along Reach 1 from stations 1880+00 to 1915+00. The dune crest is
set to be at +13 ft NAVD, the typical dune width is about 20 ft, and the dune seaward slope is 1 on 3
(vertical versus horizontal). The width of the constructed dry -sand berm (before normal profile
adjustment) in front of the toe of the initial dunes varies from 200-250 ft. The initial dune will tie into
the existing profile but in no circumstance encroach on existing vegetation or house foundations.
Final fill templates for each section of the beach will be determined close to the time of construction
(according to standard practice) based on beach conditions. These will be submitted to the
permitting agencies for approval prior to the commencement of nourishment. However, the total
project volume and the impact area will not exceed the maximum values proposed herein.
Coastal Science & Engineering 9 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

SEDIMENT QUALITYAND COMPATIBILITY
(1) Beach Sampling
CSE established ten stations in 2014 along the Buxton project area while planning for the initial
2017-2018 beach restoration project, and sediment samples were collected at 14 positions across
each station (USACE-USDOI-NPS 2015). The location of the ten along shore stations are shown in
Figure 10, and the 14 positions across each station are illustrated in Figure 11. In August 2019,
sediment samples along these stations and positions were collected in anticipation of the proposed
beach renourishment. The mean grain size of beach sand at the Buxton project area was 0.321
millimeters (mm) as of August 2019. Samples collected below -8 ft NAVD were markedly finer than
those collected from the upper portions of the profile. The mean grain size of samples collected
above mid -tide level (MTL) is 0.400 mm. Both sets of beach samples contained -7 percent shell
material,1.1 percent granules (2 to 4 mm), and -0.1 percent gravel (4 to 76 mm) by weight.
(2) Offshore Borrow Area Sediment Quality and Compatibility Analysis
The proposed offshore borrow area encompasses -200 acres and is a sandy ridge approximately
2-3 miles offshore of the old Cape Hatteras Lighthouse site within state waters (see Figure 2 and
Permit Drawing Sheets 13-14). Sixteen borings were collected in October 2020 to identify a possible
offshore borrow area, and ten vibracores were collected in April 2021 to a uniform depth of 10 ft
beneath the seafloor to confirm the sand quality. The borings were subsampled and analyzed for
grain -size distribution and comparison with the existing beach sand, then pro -rated according to
the length of each sample interval. This allows the calculation of boring statistics to a specified
"composite" depth, which is useful for the operational considerations of dredge vessels. After
calculating the composite values to 6 ft, 8 ft, and 10 ft depths, all 10-ft borings were found to have
beach -quality sand to a depth up to 10 ft.
Figure 12 shows the location of the cores along with the sediment analysis results of the 10-ft cores.
The final ten 10-ft cores collected in April 2021 are highlighted in bold text with red dots, and other
cores from previous sand searches are shown in small text with black boxes. The mean grain size
of the 10-ft cores in the proposed borrow area is 0.517 mm with 15.6 percent shell material,
7.1 percent granules (2 to 4 mm), and 0.6 percent gravel (4 to 76 mm) by weight. The boring
density is approximately 1 core per 20 acres. Based on these descriptive statistics, the proposed
borrow area contains compatible sand (Figure 13) and meets the requirements of the updated
North Carolina Technical Standards for Beach Fill Projects (15A NCAC 07H .0312 effective April 1,
2021- see Attachment 3) and National Park Service Beach Nourishment Guidance (NPS 2021a and
2021b).
Coastal Science & Engineering 10 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

The proposed 200-acre borrow area would provide up to 3.3 million cubic yards of beach -quality
sand if excavation is permitted to a depth of 10 ft. Cultural resource and geophysical surveys have
been conducted. It has been confirmed that excavation in the proposed borrow area will have no
impacts on culturally significant sites, other protected resources, or hard bottom in that area.
More details of the geotechnical data and analysis are included in Appendix A of the Environmental
Assessment.
Large sediment sampling was conducted in March 2021 as required by North Carolina sediment
standards for the proposed beach renourishment (15A NCAC 07H.0312 Effective 1 April 2021).
The fieldwork, data analysis, photo processing, and the report were performed under
Grant Contract No. CW20490 between the North Carolina Department of Environmental Quality
and the County of Dare. Large clasts are defined as sediments greater than or equal to one inch
(25.4 millimeters) in diameter, and shell material greater than or equal to three inches
(76 millimeters) in diameter. Survey results show that there were 154 samples observed along the
Buxton project area in March 2021. Each transect averaged -20 shell fragments greater than three
inches in diameter, -2 sediment samples greaterthan one inch in diameter, and <1 anthropogenic
sample greater than one inch in diameter. More details and the full conclusions are included in
Appendix C of the Environmental Assessment.
CULTURAL RESOURCES STUDY IN THE BORROW AREA
The coastal waters off the Outer Banks of North Carolina have one of the highest documented
concentrations of shipwrecks in the western Atlantic. Hundreds of vessels have been reported lost
off the Outer Banks and especially off Cape Hatteras. Weather, currents, natural magnetic
anomalies, and shoals make navigation along the Outer Banks and off Cape Hatteras more
hazardous than most East Coast areas.
Although the proposed action area lies within this area, no shipwreck remains have been
documented on the project beach or in the proposed offshore borrow area (USACE-USDOI-NPS
2015).
Data generated by a cultural resources survey by Tidewater Atlantic Research (TAR) forthe 2017-2018
project identified 123 magnetic anomalies and six acoustic targets in the vicinity of the borrow area.
While none of the acoustic signatures are suggestive of complex vessel remains, ten (10) of the
anomalies at the northern end of the sand search area were proposed for avoidance by means of no -
work buffers. Historical research indicates that the source of the rest of 113 anomalies could be early
electrical or telegraph cables or possibly SOSUS transducer arrays deployed by the US Navy in the
Coastal Science & Engineering 11 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

post -World War II period. Another no -work buffer area was identified across the north end of the
search area, of which one long linear object resembles cable, wire, or small -diameter pipe (see the
pink areas in Figure 2).
The Applicant retained TAR to conduct a similar cultural resources survey in the proposed borrow
area for the Buxton renourishment project. Field work was completed by 24 July 2021, and the
results and findings are included in Appendix G - Cultural Resources Survey of the Environmental
Assessment. Work performed by TAR consisted of a background literature survey, historical
research, and cartographical investigation. Field investigations identified one magnetic anomaly
inside the proposed borrow area, and two within the 200-ft perimeter of the borrow area. All three
anomalies represent very small ferrous objects. None appear to represent a potentially significant
submerged cultural resource and therefore, no avoidance in the proposed borrow area was
recommended. Analysis of the acoustic data identified no evidence of sonar targets in the borrow
area or its immediate vicinity. Consequently, no potentially significant submerged cultural resources
will be impacted by dredging in the proposed borrow area or its adjacent 200-ft buffer.
DUNE MANAGEMENT PLAN
Dare County proposes to integrate a dune management plan into the proposed renourishment
project. The purpose of the plan is to improve storm protection along the vulnerable section of the
project area, enhance dune growth, and provide guidance for possible sand relocation activities in
the event of future sand encroachment to existing structures.
The dune management plan proposed as part of the renourishment plan and present permit
application includes the following actions at two major stages:
(1) During Construction - Initial dunes are proposed to be built along the Village of
Buxton (ie - Reach 1 in Figure 2). The typical elevation at the top of the dune will be at
+13 ft NAVD, and the typical width of the dune crest will be around 20 ft. The typical
seaward slope will be at 1 on 3 (vertical versus horizontal). The constructed berm
width in front of the dune varies from 200-250 ft, providing sufficient dry -sand beach
to prevent escarpment at the toe of the dune following project completion. The
protective dune will tie into the existing profile but in no circumstance encroach on
existing vegetation or house foundations.
(2) Following Construction - Sand fencing will be installed on the crest of the newly
constructed dune as close to the stable vegetation line as practical. Vegetation will be
planted following renourishment. General instructions are illustrated on Permit
Drawing Sheet 15, and the exact locations of sand fencing and vegetation will be
determined based on the condition after the proposed renourishment.
Coastal Science & Engineering 12 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

METHODS OF CONSTRUCTION
The proposed beach renourishment will be placed by ocean-going trailing suction hopperdredge(s)
or cutterhead pipeline dredge(s) between the seaward crest of the existing dry beach and the outer
bar. Only the profile above high water is controllable in nourishment construction. Intertidal and
underwater portions of the profile will be subject to natural adjustment by waves. The fill will be
placed no higher than +7 ft NAVD (the average natural elevation of the berm).
Work will progress in sections within the borrow area and along the beach. Fill placement along the
beach will typically progress at an average rate of 300 ft per day. Construction activities will involve
the movement of heavy equipment and pipe along-4,000-ft reaches over a period of 1-2 weeks.
Once a section is complete, piping and heavy equipment will be shifted to a new section, and the
process will be repeated. As soon as practicable, sections will be graded and dressed to final slopes.
Beach residents along the project area will experience construction -related disruption for only
seven days or less, other than at equipment staging areas.
Land -based equipment will be brought to the site over public roads and will enter the beach at
designated beach access areas. Any alteration of dune vegetation/topography necessary for
equipment access will be authorized prior to undertaking any work and be repaired to pre -project
conditions. Daily equipment staging will be on the constructed beach seaward of the dune line.
Existing dunes and vegetation on the beach will be avoided and preserved. The Contractor will
provide for proper storage and disposal of oils, chemicals, hydraulic fluids, etc. necessary for
operation according to state and federal regulations.
Construction Schedule — The proposed project will require summer dredging because of safety
issues, particularly the lack of a nearby safe harbor for ocean dredges. Construction duration is
expected to be a maximum of -3 months if work is permitted between 1 May and 15 September.
The preferred schedule for the start of construction is May 2022. This schedule is consistent with all
prior nourishment projects in Dare County since 2011. It also follows the Applicant's goal of
maintaining the project with renourishment at approximate five-year intervals between projects.
SUPPLEMENTARY REPORTS
The following reports are prepared in support of the permit application:
Appendix A) Geotechnical Data Analysis — Contains geotechnical data on the proposed borrow
areas and the beach before the proposed renourishment. Detailed results of beach sampling and
borrow -area coring are presented, including the large sediment sampling results. The Technical
Standards for Beach Fill (15A NCAC 07H.0312 Effective 1 April 2021) was used.
Coastal Science & Engineering 13 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Appendix B) Monitoring and Mitigation Plan — This plan is based on similar special conditions
prescribed for beach nourishment during the summer months in North Carolina at Nags Head,
Rodanthe, and Buxton. It describes the anticipated monitoring and protection measures for the
proposed renourishment action. Sampling stations and data analysis methodology for the
ecological survey required by NPS is included.
Appendix C) Large Sediment Sampling — Contains large sediment survey stations, photos, and
data analysis of the large sediment sampling required by NCDEQ under Technical Standards for
Beach Fill (15A NCAC 07H.O312 Effective 1 April 2021).
Appendix D) Littoral Processes — Provides detailed discussion and additional data analyses of
erosion, wave climate, and littoral processes in the proposed Buxton project area and the predicted
performance of the proposed renourishment project.
Appendix E) Biological Assessment — Analyzes the potential effects of the proposed
renourishment on federally listed threatened, endangered, candidate animal species (wildlife,
invertebrates, and fish) or plant species, and designated or proposed critical habitats pursuant to
Section 7 of the Endangered Species Act of 1973 (as amended).
Appendix F) Essential Fish Habitat Assessment (EFH) — Evaluates the impact of the proposed
renourishment to essential fish habitat or habitat areas of particular concern for those species
managed by the South Atlantic Fisheries Management Council and Mid -Atlantic Fisheries
Management Council.
Appendix G) Cultural Resources Survey — Provides the methodology and results of a submerged
cultural resource, remote -sensing survey of the proposed borrow area and identifies any magnetic
anomalies in those areas.
REFERENCES CITED
CSE. 2013. Shoreline erosion assessment and plan for beach restoration, Rodanthe and Buxton areas, Dare County,
North Carolina. Feasibility Report for Dare County Board of Commissioners, Manteo, NC. CSE, Columbia, SC,159 pp
with synopsis plus appendices.
CSE. 2019. Amendment #2 to Agreement for Professional Services. Maintenance and FEMA Sand Restoration Project
Following the 2017-2018 Beach Nourishment at Buxton, Dare County, North Carolina. Proposal for Dare County
Board of Commissioners, Manteo, NC. CSE, Columbia, SC, 41 pp.
NPS. 2021a. Cape Hatteras National Seashore Sediment Management Framework - Final Environmental Impact
Statement. National Park Service, Fort Collins, CO, 50 pp + appendices.
NPS. 2021b. Joint Record of Decision Sediment Management Framework - Cape Hatteras National Seashore. National
Park Service, Fort Collins, CO, 13 pp + appendices.
USACE-USDOI-NPS. 2015. Environmental assessment — beach restoration to protect NC Highway 12 at Buxton, Dare
County, North Carolina. US Army Corps of Engineers, US Department of Interior, National Park Service, NPS
603/129663, Volume 1 (204 pp) and Volume II (AppendixesA to G).
Coastal Science & Engineering 14 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Albarmar0e Savnd
Nags Head
n - -
� 'w
a 1
Oregon 1nfat
I -,
Pamtico Shand
Ocracoke Island
Cwe J _ r %
National Seashom Ocracoke Wof
ropy point
Pea Island'
National
Wildlife Refuge
Rodanthe
a
a
12
Cape Hatteras ,
National Seashore i,8
Avon
PROJECT SITE
N 35 ° 16' 36"
IN 76° 31' 00 m
Atlantic Ocean
FIGURE 1. Location of Buxton and Cape Hatteras National Seashore, Dare County, North Carolina.
Coastal Science & Engineering 15 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Cape Hatteras
National Seashore
Pamlico Sound
0
f
�
I
� o
r u,
1
m o
rszo+�
'5 °°
U
� � O
O N
O In
9840+00
Z
N Cf)
t
i
Y860+DO i
- 988D+OD
�
� 4
12 j
Lo N
1900+00
o
o —' o
x o c
n + o
i
h
c Cc �
!
t
tt
y�D+OQ
Cape
• Hatteras
Light
rOxoD Cape Hatteras
National Seashore
18g0,00
19g3+77
0 2000,
Scab
A t l a n t i c O c e a n
C)
O O
LO
lC� +
LO
CN
Q O co,
V O O
47 + O
O
O Q N
ti
�a
o~
C�
0
L
a Proposed
Borrow Area
10-ft Vibracores
�� J •/
"No Work" Buffer Zones
Previous Cores �
/ti 2017 Borrow Area
FIGURE 2. Proposed beach renourishment for NC 12 at Buxton showing the project limits and offshore
borrow area.
Coastal Science & Engineering 16 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

FIGURE 3a. Week's Marine's 30-inch Cutter suction dredge CRMcCaskill with dimensions of
230'x62'x14' and 17,400 total horsepower (Thp) [Source: weeksmarine.com/equipment]. It
was onsite from 21 June to 23 August 2017 and completed approximately 1 million cubic
yards of work during the 2017-2018 Buxton beach nourishment project.
FIGURE 3b. Week's Marine's 4,000 cy trailing suction hopper dredge RN Weeks with
dimensions of 282.5'x54.1'x22.2' and 9,530 Thp [Source: weeksmarine.com/equipment]. It
was onsite from 11 October 2017 to 28 January 2018 and completed approximately 1
million cubic yards of work during the 2017-2018 Buxton beach nourishment project.
FIGURE 3c. Week's Marine's 8,550 cy trailing suction hopper dredge Magdalen with
dimensions of 363'x79.5'x27.3' and 14,003 Thp [Source: weeksmarine.com/equipment]. It
was onsite from 9 January to 27 February 2018 and completed approximately 600,000 cy of
work during the 2017-2018 Buxton beach nourishment project.
Coastal Science & Engineering 17 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Weeks Marine Production Rates versus Wave Heights
Peak Wave Height (ft) • CR McCaskill • RN Weeks • Magdalen
30 70,000
• • CR McCaskill Worked 37 days
25 m RN Weeks Worked 71 days 60,000
• Magdalen Worked 34 days
m a
s • • • • 50,000
un 20 -
W • • • m u
_ • 40,000 0
15 • • v -
• ;----------------- � - -------------- -
c� .
• • 30,000 0
ra
a 10 ----
0-- I S
0 ' • . • 20,000 a
oa•
0 5 • • • • 0 `•i ••
t % W W 69 10,000
• • • Dredging threshold • • • to
•
0 W j • i• • • M •s• •• 0
6/21 7/21 8/20 9/19 10/19 11/18 12/18 1/17 2/16
Date
FIGURE 4. Daily production rates of the three dredges in relation to the offshore wave climate at Diamond
Shoals (NDBC wave buoy Station 41025) during construction for the 2017-2018 Buxton beach restoration
project.
Weeks Marine Cumulative Production versus Peak Wave Heights
Peak Wave Height (ft) —Cumulative Volume (cy)
30 3,000,000
CR McCaskill Completed -1 million cy
25 RN Weeks Completed -1 million cy 2,500,000
3-Magdalen Completed-600,000 cy
M U
d0
ai
= 20 2,000,000 E
a m o
M� i
15-------------!-------------- Y - -- ------------'---------- --- --- ---- 1,500,000 ._
Q)
+,
`o ;m a
ro
t �
E
U
5 t 500,000
Dredging threshold
0 0
6/21 7/21 8/20 9/19 10/19 11/18 12/18 1/17 2/16
Date
FIGURE S. Cumulative production rates of the three dredges in relation to the offshore wave climate at
Diamond Shoals (NDBC wave buoy Station 41025) during construction for the 2017-2018 Buxton beach
restoration project.
Coastal Science & Engineering 18 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

2,500,000
2,000,000
a
u
'E 1,500,000
6 1,000,000
F-
Volume Changes by Reach from Foredune to -24 FT NAVD
(Relative to Pre -Nourishment Condition of May 2017)
1 2017-2018 Nourishment
i Year 1 Pre -Florence (June 2018)
Year 1 Post -Florence (October 2018)
■ Year 2 Pre -Dorian (June 2019)
■ Year 2 Post -Dorian (November 2019)
■ Year 3 (AuRust 20201
O
500,000 00 ,n ,n ,n ,n
o ko � Ln � n
ON � O to'
u1 m N N
0
R1 (Buxton)
(4,500 ft)
O
O
-
O
O
O
Ln
rj
O
0
CIZ
o
o
W
r,
v N
rn
�
Ln Lo
R2 (National Seashore)
(11,000 ft)
0
0
C
0
0
m
N Ln
N
D*
rh
14
C
O)
Ln
c
N
m
ri
LO
M
W
tD
�p
Total
(15,500 ft)
FIGURE 6. Cumulative total volume along the Buxton project area after the completion of the 2017-2018
beach restoration project relative to the pre -project condition in May 2017.
1400
Unit Volumes Comparisons Along the Entire Project Area
(From Foredune to -24 ft NAVD)
1200 Reach 2 - National Seashore Reach 1 - Buxton
1000
aD
E
0
4 � 800
,fill)
—Pre-Project (May 2017)
—Year 1 Pre -Florence (June 2018)
—Year 1 Post -Florence (October 2018)
Year 2 Pre -Dorian (June 2019)
Year 2 Post -Dorian (November 2019)
—Year 3 (August 2020)
400
1770+00 1790+00
North
1810+00 1830+00 1850+00 1870+00 1890+00 1910+00 1930+00
Station South
FIGURE 7. Unit volume along the Buxton project area before and after the completion of the 2017-2018
beach restoration project from May 2017 to August 2020.
Coastal Science & Engineering 19 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

. _
qOJ
FIGURE 8a. Ground and aerial images taken 15 April 2021- looking south. The Village of Buxton north limit
is located approximately at the end of the northernmost building showing near the bottom of the photo.
Three years after the initial 2017-2018 beach restoration project, almost all nourishment sand was lost
outside of the project limits beyond the depth of closure. There was little dry -sand beach in front of the
oceanfront, and sandbags were installed as a temporary shoreline protection measure. NC Highway 12 was
once again vulnerable for flooding and breaching.
Wd
..-7777
9
FIGURE 8b. Ground and aerial images taken 15 April 2021- from the Village of Buxton looking north into
the Cape Hatteras National Seashore.
Coastal Science & Engineering 20 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

National Seashore Station 1840+00
15
- Aug 2020 Profile
10
_
Fill Vol
5
MHW
Q\\
0
z
\ -----MLW-------
� r w
M
-10
\
m
W
-16
Berm Elevation +7.0 ft NAVD ` >
Berm Width 132 ft
-20
Fill Density 50 cylft
-25
0 200 400 600 800 1000 1200
Distance from Baseline (ft)
15
10
-20
-25
Buxton Station 1890+00
MHW
----- MLW-------
Berm Elevation +7.0 ft NAVD
Berm Width 256 ft
Fill Density 180 cylft
Typical Dune Width 20 ft
Aug 2020 Profile
Fill Vol
0 200 400 600 800 1000 1200
Distance from Baseline (ft)
FIGURE 9. Representative fill templates at station 1890+00 for Reach 1 -Buxton and station 1840+00 for
Reach 2 - National Seashore. Beach profiles represent the beach condition in August 2020. An initial dune
is proposed to be constructed along Reach 1. The dune crest is set to be at +13 ft NAVD and the seaward
slope is 1 on 3. The typical dune crest width is 20 ft, and the constructed dry -sand berm in front of the dune
is 256 ft for station 1890+00.
Coastal Science & Engineering 21 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

FIGURE 10. Location of sediment sample transects (14samples pertransect) along the
Buxton project area. Samples were collected in August 2019.
Coastal Science & Engineering 22 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

20 ft (%Dune
Dune
Toe
1oft--- Berm Crest
Berm MHW
MTL
Sediment Grab Sample Positions
(Typical Beach Profile)
0fl
MLW Bar -8
-10fl ------------ - - - - - -............... -12
Trough '10
-20
-20 ft ------------------ --- --- ----------------------------------------- - --- --- --- --- --- --
30 fl F
500 ft 1000 ft 1500 ft
-24
2000 ft 2500 ft
FIGURE 11. Sample positions for "beach" grab samples along Buxton following North Carolina sediment sampling criteria
rules. The Buxton littoral profile exhibits a narrow berm (dry -sand beach) and deep trough separating the outer bar from
the beach. Elevations and depths (y-axis) are relative to approximately Mean Sea Level.
1 0 aoo
Scale (Feet)
BUX-42
/-BU,X-35
0.596
4.9
4 9
BUX•43
10,11
0552
0,478
22.1
118
77/22.5
37
BUX-41
0,536
15.0
BUX-44
"flux-o4
3,8
0,557
17.9
10,9
BUX-40
16.5 BUX-39 o au -0s
12.6 0.579
15.5
3.8
a Bux-35
-
/ 0 7x-3B
Bux-33 /
o Bux�1 /
Previous Borrow Area (2018)
o Bu/34
o Bux-32 /
Bux-29 /
/
11,4
3.6
Boring
MGS (mm)
Shell %
Gravel %
Granule %
BUX-35
0.478
11.8
0.0
3,7
BUX-36
0.268
11.1
0.0
4,9
BUX-37
0.512
22.5
2.3
15.3
BUX-38
0.574
114
0.0
3.6
BUX-39
0.579
15.5
0.0
3,8
BUX-40
0.681
16.5
0.0
12.6
BUX-41
0.536
15.0
0.0
3,8
BUX-42
0.596
12.6
0.0
101
BUX-43
0.552
22.1
0.9
6,8
BUX-44
0.557
17.9
2.3
g,5
FIGURE 12. Mean grain size, percent shell, and percent gravel for core composite samples to 10 ft in
the proposed Buxton offshore borrow area based on borings obtained in April 2021. Composite results
of the ten 10 ft vibracores are listed in table on the lower right. The ten 10-ft vibracores obtained in
2021 are highlighted in bold text with red dots. Other cores from previous sand searches are shown in
small text with black boxes. The mean grain size of the ten 10-ft cores is 0.517 mm with 15.6 percent
shell material, 7.1 percent granules (2 to 4 mm), and 0.6 percent gravel (4 to 76 mm) by weight.
Coastal Science & Engineering 23 Permit Application - Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

Grain Size Distribution
Grain Size (mm)
10016
6 4 2 1 0.5 0.25 0.125 0.0625
Borrow Area 10 ft COMP
90
Beach
....:....:....:
Project CSE 2403-M
Location Buxton (NC)
80
:.....................:...
:......... :. .. ...
Date May 2021
70
=
BA 10 ft COMP Mean 0.517 mm
BA 10 ft COMP STD 0.426 mm
60
+........................
BA 10 ft COMP Skew-0.489 mm
`
BA 10 ft COMP Kurt 4.107 mm
50
BA 10 ft COMP Shell 12.3%
40
:....... =
All Beach Mean 0.321 mm
All Beach STD 0.552 mm
30
............................
..•....=
All Beach Skew -1.045 mm
All Beach Kurt 5.621 mm
20
:....:....:....:........:........
;...;...
All Beach Shell 7.2%
10
.
0
4
-3 -2 -1 0 1 2 3
4
Grain Size (0)
Grain Size Distribution
Grain Size (mm)
10016
8 4 2 1 0.5 0.25 0.125 0.0625
— Borrow Area 10 ft COMP
90
— Vis Beach
....:....:.. .
Project CSE 2403-M
Location Buxton (NC)
80 ...:
........ .............. ..: ..
............ .....:...:
Date May 2021
70 ...
..............:
BA 10 ft COMP Mean 0.517 mm
BA 10 ft COMP STD 0.426 mm
60
• • • = • > .
. . ` .. :....:.. .:.. .
BA 10 ft COMP Skew-0.489 mm
BA 10 ft COMP Kurt 4.107 mm
50
BA 10 ft COMP Shell 12.3%
40
• • .• • : - -
Vis Beach Mean 0.400 mm
Vis Beach STD 0.636 mm
30...:....:....:........:....:........
.. ... ..............
Vis Beach Skew -1.073 mm
Vis Beach Kurt 6.358 mm
20....:....:....:....:....:....:..
..
:.. :....:....:.... ; ... ; ...
Vis Beach Shell 7.2%
10
.........
...
0
-4
-3 -2 -1 0 1 2 3
4
Grain Size (0)
FIGURE 13. GSDs for Buxton native beach samples (n=140) compared with offshore samples to 10 ft
(composite). The "Vis Beach" consists of all native samples collected on the visible beach (above MTL),
while "All Beach" contains all samples. In both cases, the borrow area sediments are expected to be
coarser than the native beach initially. Over time, the grain size of the post -nourishment beach is
expected to move closer to the historical grain size distribution around Buxton.
Coastal Science & Engineering 24 Permit Application — Narrative
Beach Renourishment to Protect NC Hwy 12 at Buxton Buxton, Dare County, North Carolina

SIGN UP SHEET
INTERAGENCY/SCOPING MEETING
ATTACHMENT 1
Scoping Meeting - Buxton (Dare County) Re -nourishment and Groin Restoration Project
Purpose of this meeting is to discuss a proposed project and provide environmental permitting and regulatory information
which will improve communications and the permitting processes.
November 7, 201910 am
Conference line — 919-420-7945
j Name
Agency
Phone
Email
Haicling Kaczkowski
Coastal Science &Engineering
803-799-8949
[e-mail]
Tim Kana
Coastal Science &
803-799-8949
[e-mail]
Engineering
Julia Berger
CZR, Inc
910-392-9253
[e-mail]
✓ John Clawson
Dare County
252-475-5730
[e-mail]
il Robert Outten
Dare County
252-475-5800
[e-mail]
1/ Brent Johnson
Dare County
252-475-5628
[e-mail]
Raleigh Bland
USACE
910-251-4564
[e-mail]
V-'Josh Pelletier
USACE
910-251-4605
[e-mail]
I Twyla Cheatwo a
NOAA Habitat
252-7-28-875$
[phone] Ext.
[e-mail]
L"Kathryn Matthews
USFWS
27
J®he-John--R
USFWS
[phone] ext.
[e-mail]
26
i' Heather Coats
Coastal Management
910-796-7302
[e-mail]
Jonathan Howell
Coastal Management
252-948-38S1
Jonathan. [e-mail]
252-808-2808
[e-mail]
Gregg Bodnar
Coastal Management
Yvonne Carter
Coastal Management
252-264-3901
[e-mail]
Maria Dunn
V
NCWRC
252-948-3916
[e-mail]
Curt Weychert
DMF
252-808-8050
[e-mail]
Kelly Daigle
NPS-Cape Hatteras
[e-mail]
National Seashore
Sabrina Henry
NPS-Cape Hatteras
252-475-9019
[e-mail]
National Seashore
NPS-Cape Hatteras
252-475-9031
Mark Dawdle
[e-mail]
National Seashore
[e-mail]
[e-mail]
�l Anthony Scarbraugh
DWR-401
252-948-3924
/ Chris Pullinger
DWR-401
252-948-3973
i
NCDEQ WASHINGTON REGIONAL OFFICE
943 WASHINGTON SQUARE MALLWASHINGTON, NC 27889 252-946-6481, FAX [phone]
All
1 of 2 25

ATTACH ME N T 2
Contact Name *
Contact Email Address*
Project Owner*
Project Name*
Project County*
Owner Address:*
Is this a transportation project?*
Haiqing Kaczkowski
[e-mail]
Dare County
Beach Renourishment to Protect NC Highway 12 at Buxton, Dare County
Dare
Street Address
954 Marshall Collins Drive
Address Line 2
City
Manteo
Fbstal / Zip Code
27954
r Yes r No
Type(s) of approval sought from the DWR:
W 401 Water Quality Certification - 17- 401 Water Quality Certification -
Regular Express
F Individual Permit F Modification
F Shoreline Stabilization
Does this project have an existing project ID#?*
r Yes r No
State / Rovince / Fbgion
NC
Country
USA
Do you know the name of the staff member you would like to request a meeting with?
Rick Trone
Please give a brief project description below and include location information.*
26

The proposed project is to continue to protect NC Highway 12 and
replenish sand losses due to chronic erosion, hurricanes, and winter
storms after the completion of the 2017-2018 beach nourishment.
The 401 Water Quality Certification received for the 2017-2018
project is DWR #15-1087 (dated 23 November 2015).
The proposed project area encompasses the same 15,500 linear feet
of the oceanfront as the 2017-2018 project including —2.2 miles in the
Cape Hatteras National Seashore and —0.8 miles along the Village of
Buxton. Location of the project is at 35°16'5"N and75°31'6"W. It
would be implemented using the same construction method (ie
offshore dredging) and would be completed within the same
construction window (ie during summer months). Beach -quality sand
will be excavated from an offshore borrow area near Buxton Village
via hydraulic or hopper dredge, and up to 1,200,000 cubic yards of
sand will be placed along the project area. The average fill density is
approximately 77 cubic yards per foot of shoreline, and the beach
along the project area will be widened by an average of —75 feet after
natural profile adjustment. The proposed project will also include a
dune management plan along the Village of Buxton including dune
construction, sand fencing installation, and dune vegetation planting.
The official pre -application scoping meeting was held on 7 November
2019 with state and federal agencies. Anthony Scarbraugh and Chris
Pullinger of the NCDWR attended the meeting.
By digitally signing below, I certify that I have read and understood that per the Federal Clean Water Act Section
401 Certification Rule the following statements:
• This form completes the requirement of the Pre -Filing Meeting Request in the Clean Water Act Section 401 Certification
Rule.
• I understand by signing this form that I cannot submit my application until 30 calendar days after this pre -filing
meeting request.
• I also understand that DWR is not required to respond or grant the meeting request.
Your project's thirty -day clock started upon receipt of this application. You will receive notification regarding meeting location
and time if a meeting is necessary. You will receive notification when the thirty -day clock has expired, and you can submit an
application.
Signature *
Submittal Date 6/14/2021
27

IZ/_l:l:T_VIIIkW=_4aLTPI:IAi14011 W
15A NCAC 07H .0312 TECHNICAL STANDARDS FOR BEACH FILL PROJECTS (effective April 2021)
Placement of sediment along the oceanfront shoreline is referred to in this Rule as "beach fill." Sediment
used solely to establish or strengthen dunes shall conform to the standards contained in 15A NCAC 07H
.0308(b). Sediment used to re-establish state -maintained transportation corridors across a barrier island
breach in a disaster area as declared by the Governor is not considered a beach fill project under this Rule.
Beach fill projects including beach nourishment, dredged material disposal, habitat restoration, storm
protection, and erosion control may be permitted under the following conditions:
(1) The applicant shall characterize the recipient beach according to the following methodology. Initial
characterizations of the recipient beach shall serve as the baseline for subsequent beach fill
projects:
(a) Characterization of the recipient beach is not required for the placement of sediment directly
from and completely confined to a maintained navigation channel or associated sediment
basins within the active nearshore, beach or inlet shoal system. For purposes of this Rule,
"cape shoal systems" include Frying Pan Shoals at Cape Fear, Lookout Shoals at Cape Lookout,
and Diamond Shoals at Cape Hatteras;
N/A
(b) Sediment sampling and analysis shall be used to capture the spatial variability of the sediment
characteristics including grain size, sorting and mineralogy within the natural system;
Sediment samples were collected at ten (10) stations along the beach and fourteen (14) cross -
shore locations between the foredune and 24 ft depth contour within the proposed project area.
Samples were also collected at various locations and multiple depths within the proposed borrow
area to capture the three-dimensional spatial variability of the sediment characteristics.
(c) Shore -perpendicular transects shall be established for topographic and bathymetric surveying
of the recipient beach. Topographic and bathymetric surveying shall occur along a minimum
of five shore -perpendicular transects evenly spaced throughout the entire project area with
spacing not to exceed 5,000 feet (1,524 meters) in the shore -parallel direction. Each transect
shall extend from the frontal dune crest seaward to a depth of 20 feet (6.1 meters) or to the
shore -perpendicular distance 2,400 feet (732 meters) seaward of mean low water, whichever
is in a more landward position. Elevation data for all transects shall be compliant with
Standards of Practice for Land Surveying in North Carolina (21 NCAC 56.1600);
Shore -perpendicular, topographic and bathymetric surveying of the recipient beach has been
conducted in August 2020 at Buxton. The surveying extends from the foredune seaward to a depth
of over 40 feet. Fifty-three (53) transects were surveyed along the —3-mile project area and the
adjacent areas, and the spacing between each transect was 500 ft. Elevation data for all transects
are referenced to the North American Vertical Datum of 1988 (NA VD 88) and the North American
Datum of 1983 (NAD 83). Details of the survey and its results are described in the Environmental
Assessment (EA) — Appendix D - Littoral Processes.
M

(d) Along each transect, at least one sample shall be taken from each of the following
morphodynamic zones where present: frontal dune, frontal dune toe, mid berm, mean high
water (MHW), mid tide (MT), mean low water (MLW), trough, bar crest and at even depth
increments from 6 feet (1.8 meters) to 20 feet (6.1 meters) or to a shore -perpendicular
distance 2,400 feet (732 meters) seaward of mean low water, whichever is in a more landward
position. The total number of samples taken landward of MLW shall equal the total number
of samples taken seaward of MLW;
Sediment samples were collected along five beach transects in August 2019 (see the Geotechnical
Report). Fourteen (14) samples were taken along each beach transect at the following cross -shore
locations (see Figures 10 and 11 in the Narrative or Figure 2.1 in the Geotechnical Report):
• dune face
• toe of the dune
• berm
• berm crest
• MHW
• MTL
• MLW
• Trough
• inshore bar
• -8 ft NA VD
• -12 ft NA VD
• -16 ft NA VD
• -20 ft NA VD
• -24 ft NA VD
There are 7 samples taken landward of MLW (including MLW) and 7 samples taken seaward of
MLW (not including MLW).
(e) For the purpose of this Rule, "sediment grain size categories" are defined as "fine" (less than
0.0625 millimeters), "sand" (greater than or equal to 0.0625 millimeters and less than 2
millimeters), "granular" (greaterthan or equal to 2 millimeters and less than 4.76 millimeters)
and "gravel" (greater than or equal to 4.76 millimeters and less than 76 millimeters). Each
sediment sample shall report percentage by weight of each of these four grain size categories;
Sediment samples were inspected for mud then washed, dried, weighed in splits for analysis of
grain size, gravel, and shell content (see Sections 3 and 4 of the Geotechnical Report). Grain size
distribution of each sample is shown in Attachment 1 of the Geotechnical Report. Descriptive
statistics (mean, standard deviation, skewness, and kurtosis), along with USCS and Wentworth
descriptions, and shell and gravel contents, are compiled in Tables 3.1a and 3.1b. Tables 3.2 and
3.3 contain mean grain sizes, standard deviations, and shell and gravel contents averaged by
station as well as cross shore position. Overall, materials on the native beach and the borrow
areas are both defined as "sand" based on the Rule with fine-grained sediment contents for the
29

recipient beach are less than 1% the average granular content (2 to 4 mm diameter) is 1.1% and
the gravel content (2 to 76 mm) is 0.1% (see Tables 3.3 and Figure 3.1 of the Geotechnical Report).
Detailed results for the proposed borrow areas are in included in Section 4 of the Geotechnical
Report.
(f) A composite of the simple arithmetic mean for each of the four grain size categories defined
in Sub -Item (1)(e) of this Rule shall be calculated for each transect. A grand mean shall be
established for each of the four grain size categories by summing the mean for each transect
and dividing by the total number of transects. The value that characterizes grain size values
for the recipient beach is the grand mean of percentage by weight for each grain size category
defined in Sub -Item (1)(e) of this Rule;
Mean (and a grand mean for composite samples) grain size for individual samples and composite
samples are summarized in Tables 3.1 to 3.3 and plotted in Figures 3.1 to 3.4 of the Geotechnical
Report. The grand mean grain diameter of all beach samples collected in March 2021 is 0.289
mm. The mean content by weight of fine-grained sediment for the recipient beach is less than 1%
mean granular content is 1.1% and gravel content is 0.1% (see Tables 3.1 to 3.3).
(g) Percentage by weight calcium carbonate shall be calculated from a composite of all sediment
samples. The value that characterizes the carbonate content of the recipient beach is a grand
mean calculated by summing the average percentage by weight calcium carbonate for each
transect and dividing by the total number of transects;
Calcium carbonate (CaCO3) content fie — "shell" content) was determined by acid -burning using
dilute hydrochloric acid. Percentage by weight calcium carbonate was calculated for each sample
as well as for a composite of all samples along each transect. The results are listed in Tables 3.1
to 3. of the Geotechnical Report, and plotted in Figure 3.4 of the same report. The arithmetic
average shell content for all samples (n=140) was 7.2% in August 2019 (see Table 3.3).
(h) The number of sediments greater than or equal to one inch (25.4 millimeters) in diameter,
and shell material greater than or equal to three inches (76 millimeters) in diameter shall be
calculated for an area of 10,000 square feet centered on each transect, and between mean
tide level (MTQ and the frontal dune toe within the beach fill project boundaries. A simple
arithmetic mean shall be calculated for both sediments and shell by summing the totals for
each across all transects and dividing by the total number of transects, and these values shall
be considered representative of the entire project area, and referred to as the "background"
values for large sediment and large shell material;
Some material greater than or equal to three inches (76 millimeters) in diameter was observed
along the beach in March 2021. That large-clast survey found 154 samples meeting these criteria
around the Buxton project area. On average, there were —22 sediments per survey transect with
—19 samples being derived from shelly material and —2 to 3 samples being derived from clastic or
anthropogenic material.
(1) Beaches that received sediment prior to the effective date of this Rule shall be characterized
in a way that is consistent with Sub -Items (1)(a) through (1)(h) of this Rule and may use data
collected from the recipient beach prior to the addition of beach fill where data are available,
and in coordination with the Division of Coastal Management; and
30

N/A
(j) All data used to characterize the recipient beach shall be provided in digital and hardcopy
format to the Division of Coastal Management upon request.
All data were described, analyzed, compiled, and plotted in Appendix A — Geotechnical Data.
Digital and hardcopy of the report has been submitted to the Division of Coastal Management.
(2) Characterization of borrow areas is not required if completely confined to a cape shoal system. For
the purposes of this Rule, "cape shoal systems" include the Frying Pan Shoals at Cape Fear,
Lookout Shoals at Cape Lookout, and Diamond Shoals at Cape Hatteras. The applicant shall
characterize the sediment to be placed on the recipient beach according to the following
methodology:
(a) The characterization of borrow areas including submarine sites, upland sites, and dredged
material disposal areas shall be designed to capture the spatial variability of the sediment
characteristics including grain size, sorting and mineralogy within the natural system or
dredged material disposal area;
A variety of potential borrow areas have been evaluated. Details are described in Section 4 of the
Geotechnical Report.
(b) The characterization of borrow sites may include historical sediment characterization data
where available and collected using methods consistent with Sub -Items (2)(c) through (2)(g)
of this Rule, and in coordination with the Division of Coastal Management;
The borings obtained by the application for the 2017 nourishment project (CSE 2017) were
reviewed by the Division of Coastal Management. No data were available directly from the
Division of Coastal Management.
(c) Seafloor surveys shall measure elevation and capture acoustic imagery of the seafloor.
Measurement of Seafloor elevation shall cover 100 percent, or the maximum extent
practicable, of each submarine borrow site and use survey -grade swath sonar (e.g. multibeam
or similar technologies). Seafloor imaging without an elevation component (e.g. sidescan
sonar or similar technologies) shall also cover 100 percent, or the maximum extent
practicable, of each site. Because shallow submarine areas can provide technical challenges
and physical limitations for acoustic measurements, Seafloor imaging without an elevation
component may not be required for water depths less than 10 feet (3 meters). Alternative
elevation surveying methods for water depths less than 10 feet (3 meters) may be evaluated
on a case -by -case basis by the Division of Coastal Management. Elevation data shall be tide -
and motion -corrected and compliant with Standards of Practice for Land Surveying in North
Carolina (21 NCAC 56.1600). Seafloor imaging data without an elevation component shall also
be compliant with Standards of Practice for Land Surveying in North Carolina (21 NCAC
56.1600) of the N.C. General Statutes. For offshore dredged material disposal sites, only one
set of imagery without elevation is required. Sonar imaging of the seafloor without elevation
is not required for borrow sites completely confined to maintained navigation channels,
sediment deposition basins within the active nearshore, beach or inlet shoal system;
31

A detailed bathymetric survey with 1000 ft spacing for track lines of proposed borrow area was
completed by CSE in October 2020. A submerged cultural resource remote -sensing survey of the
proposed borrow area is described in Appendix G — Cultural Resources Survey.
The proposed borrow areas are situated 2 to 3 miles off the historic Cape Hatteras lighthouse site.
The depths of the areas are from 30 ft to 50 ft with an average of —40 to 45 ft below 0 (NAVD). A
marine cesium magnetometer and digital sidescan sonar along with other supporting equipment
will be employed to collect bathymetric, magnetic and acoustic data. Details of the study will be
included in EA Appendix G — Cultural Resources Study.
(d) Geophysical imaging of the seafloor subsurface shall be used to characterize each borrow site.
Because shallow submarine areas can pose technical challenges and physical limitations for
geophysical techniques, subsurface data may not be required in water depths less than 10
feet (3 meters), and the Division of Coastal Management shall evaluate these areas on a case -
by -case basis. Subsurface geophysical imaging shall not be required for borrow sites
completely confined to maintained navigation channels, and for sediment deposition basins
within the active nearshore, beach or inlet shoal system, or upland sites. All final subsurface
geophysical data shall use accurate sediment velocity models for time -depth conversions and
be compliant with Standards of Practice for Land Surveying in North Carolina (21 NCAC
56.1600;
To ensure sufficient data would be available to locate any potentially significant magnetic
anomalies and sonar targets in the proposed borrow area, remotely sensed data are collected
along parallel lanes spaced on 50 foot intervals. A submerged cultural resource remote -sensing
survey of the proposed borrow area is described in Appendix G — Cultural Resources Survey.
(e) With the exception of upland borrow sites, sediment sampling of all borrow sites shall use a
vertical sampling device no less than 3 inches (76 millimeters) in diameter. Characterization
of each borrow site shall use no fewer than five evenly spaced cores or one core per 23 acres
(grid spacing of 1,000 feet or 305 meters), whichever is greater. Characterization of borrow
sites completely confined to maintained navigation channels or sediment deposition basins
within the active nearshore, beach or inlet shoal system shall use no fewer than five evenly
spaced vertical samples per channel or sediment basin, or sample spacing of no more than
5,000 linear feet (1,524 meters), whichever is greater. Two sets of sampling data (with at
least one dredging event in between) from maintained navigation channels or sediment
deposition basins within the active nearshore, beach or inlet shoal system, or offshore
dredged material disposal site (ODMDS) may be used to characterize material for subsequent
nourishment events from those areas if the sampling results are found to be compatible with
Sub -Item (3)(a) of this Rule. Vertical sampling shall penetrate to a depth equal to or greater
than permitted dredge or excavation depth or expected dredge or excavation depths for
pending permit applications. Because shallow submarine areas completely confined to a
maintained navigation channel or associated sediment basins within the active nearshore,
beach or inlet shoal systems can pose technical challenges and physical limitations for vertical
sampling techniques, geophysical data of and below the seafloor may not be required in water
depths less than 10 feet (3 meters), and shall be evaluated by the Division of Coastal
Management on a case -by -case basis;
32

Cores at the proposed offshore borrow areas were obtained under a sub -consultant agreement
with American Vibracore Services (see Section 2.2 of Appendix A — Geotechnical Data). All cores
across the search area were collected to a uniform depth of 10 ft beneath the seafloor (see Section
4 and Table 4.1 of the Geotechnical Report). There are 10 cores in the —200-acre borrow area,
yielding a core density of 1 core per —20 acres. The proposed excavation depth is 10 ft below the
existing grade with 1 ft of over dredge. Existing core logs are included in Attachment 2 of the
Geotechnical Report.
(f) Grain size distributions shall be reported for all sub -samples taken within each vertical sample
for each of the four grain size categories defined in Sub -Item (1)(e) of this Rule. Weighted
averages for each core shall be calculated based on the total number of samples and the
thickness of each sampled interval. A simple arithmetic mean of the weighted averages for
each grain size category shall be calculated to represent the average grain size values for each
borrow site. Vertical samples shall be geo-referenced and digitally imaged using scaled, color -
calibrated photography;
All sediment samples within each vertical sample were inspected for mud then washed, dried,
weighed in splits for analysis of grain size, gravel, and shell content (see the methodology in
Section 2 of the Geotechnical Report). Grain size distribution of each sample is shown in
Attachment 3A of the Geotechnical Report. Descriptive statistics for samples in the borrow areas
(mean, standard deviation, skewness, and kurtosis), along with USCS and Wentworth descriptions,
and shell and gravel contents, are compiled in Tables 4.1a and 4.1b. Tables 4.2, 4.3, and 4.4
contain the same information for individual cores composited to a specified depth (eg 6 ft, 8 ft, 10
ft). Overall, fine-grained sediment contents for the final proposed borrow area are less than 1%
granular and gravel contents are generally less than 10% with an average of 7.1% and 0.6%
respectively, and shell content is generally less than 20% with an average of 15.6% (see Tables 4.1
and 4.4 of the Geotechnical Report).
(g) Percentage by weight of calcium carbonate shall be calculated from a composite sample of
each core. A weighted average of calcium carbonate percentage by weight shall be calculated
for each borrow site based on the composite sample thickness of each core. Carbonate
analysis is not required for sediment confined to maintained navigation channels or
associated sediment deposition basins within the active nearshore, beach or inlet shoal
system; and
Calcium carbonate (CaCO3) content (ie — "shell" content) was determined by acid -burning using
dilute hydrochloric acid (see Table 4.1 of the Geotechnical Report). Percentage by weight calcium
carbonate was also calculated for a composite of each core at different thickness intervals. The
results are listed in Tables 4.2, 4.3, 4.4, and 5.1 of the Geotechnical Report. Table 4.4 shows the
arithmetic average for all cores composited to 10 ft across Borrow Area 1 is 15.6% which is — 8%
greater than the recipient beach.
(h) All data used to characterize the borrow site shall be provided in digital and hardcopy format
to the Division of Coastal Management upon request.
All data were described, analyzed, compiled, and plotted in the Geotechnical Report. Digital and
hardcopy of the report has been submitted to the Division of Coastal Management.
33

(3) Compliance with these sediment standards shall be certified by an individual licensed pursuant to
Chapter 89C or 89E of the N.C. General Statutes. Sediment compatibility is determined using the
following criteria:
(a) Sediment completely confined to the permitted dredge depth of a maintained
navigation channel or associated sediment deposition basins within the active
nearshore, beach or inlet shoal system is considered compatible if the average
percentage by weight of fine-grained (less than 0.0625 millimeters) sediment is less
than 10 percent;
(b) The average percentage by weight of fine-grained sediment (less than 0.0625
millimeters) in each borrow site shall not exceed the average percentage by weight
of fine-grained sediment of the recipient beach characterization plus five percent
(c) The average percentage by weight of granular sediment (greater than or equal to 2
millimeters and less than 4.76 millimeters) in a borrow site shall not exceed the
average percentage by weight or coarse -sand sediment of the recipient beach
characterization plus 10 percent
(d) The average percentage by weight of gravel (greaterthan or equal to 4.76 millimeters
and less than 76 millimeters) in a borrow site shall not exceed the average percentage
by weight of gravel -sized sediment for the recipient beach characterization plus five
percent;
(e) The average percentage by weight of calcium carbonate in a borrow site shall not
exceed the average percentage by weight of calcium carbonate of the recipient beach
characterization plus 15 percent; and
(f) Techniques that take incompatible sediment within a borrow site or combination of
sites and make it compatible with that of the recipient beach characterization shall
be evaluated on a case -by -case basis by the Division of Coastal Management.
(4) Excavation and placement of sediment shall conform to the following criteria:
(a) In order to protect threatened and endangered species, and to minimize impacts to
fish, shellfish and wildlife resources, no excavation or placement of sediment shall
occur within the project area during any seasonal environmental moratoria
designated by the Division of Coastal Management in consultation with other State
and Federal Agencies, unless specifically approved by the Division of Coastal
Management in consultation with other State and Federal agencies. The time
limitations shall be established during the permitting process and shall be made
known prior to permit issuance; and;
(b) The total sediments with a diameter greater than or equal to one inch (25.4
millimeters), and shell material with a diameter greater than or equal to three inches
(76 millimeters) is considered incompatible if it has been placed on the beach during
the beach fill project, is observed between MTL and the frontal dune toe, and is in
excess of twice the background value of material of the same size along any 10,000
34

square feet section of beach within the beach fill project boundaries. In the event that
more than twice the background value of incompatible material is placed on the
beach, it shall be the permittee's responsibility to remove the incompatible material
in coordination with the Division of Coastal Management and other State and Federal
resource agencies.
35