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SUMMARY OF PROPOSED PROJECT
The North Carolina Department of Transportation (NCDOT) proposes to provide temporary
protection to North Carolina Highway 12 (NC 12) on Hatteras Island in Dare County for a
period of five to ten years until a long-term solution is implemented. The project location is
shown in Figure 1. This portion of NC 12 is vulnerable due to frequent overwash and
flooding from the Atlantic Ocean. At such times, NC 12 is impassable, leaving several
communities south of this area without highway access to the mainland. The frequent
overwash has required continual maintenance of the roadway and threatens the viability of
the highway, which is the only highway link from the southern parts of Hatteras Island to the
Dare County mainland.
The purpose of the proposed project is to maintain the integrity and viability of the roadway
with minimal interruption of traffic service due to a moderate storm event between Buxton
and Avon for a period of 5-10 years until a long-term solution is in place. The proposed
project is not intended as a long-term solution for the protection of NC 12. NCDOT
recognizes the need for more substantial improvements to the NC 12 corridor and is in the
process of working toward that end in coordination with other federal, state, and local
agencies. Implementation of a long-term solution is presently estimated to be 5-10 years
away.
Ten alternatives to provide temporary protection were originally selected for analysis by the
NEPA/404 Merger Process project team on February 25, 2000 and are presented in this
document. After analysis, the project team reduced the number of alternatives to seven on
June 20, 2000. These alternatives are discussed in detail in Section III of this document. At
this point in time, there is no preferred alternative.
No significant long-term adverse environmental impacts will result from any of the
alternatives under consideration. Planning for these activities has been coordinated with
appropriate state and federal permit agencies.
I. SUMMARY OF SPECIAL PROJECT COMMITMENTS
Jurisdictional Issues
Any activities undertaken that occur within the splash zone, sound, or ocean will require
authorization from the U. S. Army Corps of Engineers. Additionally, the project lies within
an Ocean Hazard Area of Environmental Concern (AEC) and is under the jurisdiction of the
North Carolina Division of Coastal Management (DCM). Activities within the Ocean
Hazard AEC will require authorization from the DCM under the Coastal Area Management
Act (CAMA). This project also lies within the Cape Hatteras National Seashore; therefore, a
Special Use Permit will be required from the U. S. Department of the Interior - National
Park Service for activities occurring outside of the NCDOT right-of-way and within the Cape
Hatteras National Seashore. NCDOT will coordinate with the appropriate agencies to obtain
the necessary permits.
Even though the sheet pile in Alternative 8 would be buried under a dune and would be a
temporary feature, it would likely be considered a hardened structure under current North
Carolina Coastal Management Act and would, therefore, require a variance from the Coastal
Resources Commission to construct. Likewise, the sandbags associated with Alternates 7
and 9 are also likely to require a variance from the Coastal Resources Commission in order to
be implemented, as proposed by these alternatives.
Environmental Commitments
A public parking lot is located along NC 12 at the northern end of the study area. Regardless of
the alternative selected, temporary use of the parking lot may be necessary during construction
for staging/parking of equipment. However, access to the lot for the public will be maintained
throughout construction. If use of the parking lot as a staging area is considered, NCDOT will
coordinate with the National Park Service.
Written concurrence from the US Fish and Wildlife Service (USFWS) and the National Marine
Fisheries Service (NMFS) of the proposed project’s impacts on federally protected species will
be obtained prior to completion of a final environmental document. If a preferred alternative is
selected that “is likely to adversely affect” or “may affect” a federally protected species, NCDOT
will continue formal consultation with the USFWS through the Federal Highway Administration
(FHWA) to resolve Section 7 issues prior to completion of the final environmental document.
Should maintenance of dunes within the project be required during the nesting season, Section 7
consultation would be required with the U.S. Fish and Wildlife Service (USFWS). NCDOT will
coordinate with the USFWS on a case-by-case basis for those maintenance activities.
Coordination with the State Historic Preservation Office indicates that there is the potential to
impact the remains of shipwrecks on the beach in the project area if beach sands are disturbed
during dune replenishment or the filling of sandbags. If an alternative is selected that requires the
disturbance of beach sands (Alternative 2, 6, 7, 8, or 9), a survey will be conducted of the beach
immediately prior to construction. Upon request, the Underwater Archaeology Unit of the
Department of Cultural Resources can perform this survey. Equipment operators will be
informed of the possibility for encountering the remains of shipwrecks. If such remains are
encountered, work will be moved to another area and the Underwater Archaeology Unit of the
State Historic Preservation Office will be contacted immediately so an assessment of the
wreckage can be made and the proper course of action determined.
A recommended alternative has not been selected at this time. However, depending on the
alternative selected for implementation, specific environmental commitments are cited below for
each alternative under consideration.
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Alternative 2 (Beach Nourishment). In order to minimize impacts during the sea turtle
and shorebird nesting seasons, all sands would be placed between November 15 and
March 31 to the maximum extent practicable. However, because of the adverse wave
climate normally found in the project area during the winter months, it is probable that
the majority of the initial construction work under this alternative would be performed
during these nesting seasons. For maintenance activities associated with the beach
nourishment alternative, maintenance events could be completed during the November 15
– March 31 window if weather and sea conditions permit since smaller amounts of
material are involved. However, because of the unpredictability of sea conditions,
weather delays could force encroachment into the nesting seasons. In the event that this
alternative is selected as the preferred alternative, formal consultation with the USFWS
will be initiated and completed prior to completion of final environmental documentation.
In the event that the Beach Nourishment Alternative is selected as the recommended
alternative, a magnetometer survey of the offshore borrow site will be performed to
determine if submerged cultural resources may be present. The results of the survey will
be coordinated with the State Historic Preservation Officer to determine if additional
work is necessary. Because of the size of the area designated for borrow, it should be
possible to extract needed borrow material while maintaining adequate protective buffers
around any potential targets encountered. All cultural resources of known or potential
significance will be avoided.
Some minimal sampling has been conducted for the off-shore borrow site associated with
the Beach Nourishment alternative. Preliminary analyses indicate this material is likely
to be suitable for beach fill. If the beach nourishment alternative is selected for
implementation, additional analyses will be performed to assess its compatibility.
Alternative 6 (Road Relocation with Dune). Roadway relocation could be
accomplished during any season of the year without adversely affecting sea turtles. The
majority of the dune construction would be scheduled to occur during the winter months
(November 15-March 31) to avoid most of the sea turtle and shorebird nesting seasons;
however, some encroachment into the sea turtle nesting season may occur. Work would
be planned so that any dune construction outside of the winter months would take place
at the northern and southern ends of the project, where existing dunes would provide a
natural barrier between the beach and the work area. With these provisions, in addition
to keeping the elevation of the relocated roadway at approximately the same as the
existing roadway, it has been determined that the construction of Alternative 6 is not
likely to adversely affect sea turtles or piping plovers. Should maintenance of the project
be required during the species’ nesting seasons, additional Section 7 consultation with the
USFWS would be initiated.
Access to the informal vehicular paths between NC 12 and the Pamlico Sound will be
impacted by this alternative. In the event this alternative is selected as the preferred
alternative, NCDOT will coordinate with the National Park Service regarding the
reconnection of these paths to NC 12.
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Alternative 7 (Road Relocation with Subsurface Sandbags and a Dune). Road
relocation associated with Alternative 7 could be constructed at any time of year and
would be performed as a first phase of the project. Work on the sandbags and dunes
would occur outside the sea turtle nesting season to the maximum extent practicable;
however, some encroachment into the sea turtle nesting season may occur. Work would
be planned so that any dune construction outside of the winter months would take place
at the northern and southern ends of the project, where existing dunes would provide a
natural barrier between the beach and the work area.
Given that some work may occur during the sea turtle nesting season (primarily
associated with filling and placement of the sandbags), it has been determined that the
construction of Alternative 7 is likely to adversely affect sea turtles. If this alternative is
selected as the preferred alternative, additional consultation with the USFWS will be
required prior to completion of the final environmental document.
Access to the informal vehicular paths between NC 12 and the Pamlico Sound will be
impacted by this alternative. In the event this alternative is selected as the perferred
alternative, NCDOT will coordinate with the National Park Service regarding the
reconnection of these paths to NC 12.
Alternative 8 (Road Relocation with Sheet Piling and a Dune). Road relocation
associated with Alternative 8 could be constructed at any time of year and would be
performed as a first phase of the project. Work on the sheet pile and dunes would occur
outside the sea turtle nesting season to the maximum extent practicable; however, some
encroachment into the sea turtle nesting season may occur. Work would be planned so
that any sheet pile installation outside of the winter months would take place at the
northern and southern ends of the project, where existing dunes would provide a natural
barrier between the beach and the work area. With these provisions, it has been
determined that the construction of Alternative 8 is not likely to adversely affect sea
turtles. Should maintenance of the project be required during the nesting season,
additional Section 7 consultation with the USFWS would be required.
Access to the informal vehicular paths between NC 12 and the Pamlico Sound will be
impacted by this alternative. In the event this alternative is selected as the preferred
alternative, NCDOT will coordinate with the National Park Service regarding the
reconnection of these paths to NC 12.
Alternative 9 (Road Relocation with Surface Sandbags and Sand Cover). Road
relocation associated with Alternative 9 could be constructed at any time of year and
would be performed as a first phase of the project. Work on the sandbags and sand cover
would occur outside the sea turtle nesting season to the maximum extent practicable;
however, some encroachment into the sea turtle nesting season may occur. Work would
be planned so that any sand bag and sand cover work outside of the winter months would
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take place at the northern and southern ends of the project, where existing dunes would
provide a natural barrier between the beach and the work area.
Given that some work may occur during the sea turtle nesting season (primarily
associated with filling and placement of the sandbags), it has been determined that the
construction of Alternative 9 is likely to adversely affect sea turtles. If this alternative is
selected as the preferred alternative, additional consultation with the USFWS will be
required prior to completion of the final environmental document.
Access to the informal vehicular paths between NC 12 and the Pamlico Sound will be
impacted by this alternative. In the event this alternative is selected as the preferred
alternative, NCDOT will coordinate with the National Park Service regarding the
reconnection of these paths to NC 12.
II. PURPOSE AND NEED OF THE PROPOSED PROJECT
A. Need for Highway Protection
NC 12 is essential to the inhabitants of Hatteras Island and Dare County, as well as to the
economic vitality of the region. Nearly 4,000 people reside on Hatteras Island and NC 12
provides the only vehicular link to the mainland. Through the NC 12 corridor, visitors and
residents of Hatteras Island receive goods and services, emergency care and waste disposal in
addition to access to their homes. Tourism is the principle industry of Dare County. NC 12
provides access to the Cape Hatteras National Seashore, Pea Island National Wildlife Refuge,
and vacation destinations on Hatteras and Ocracoke Islands. Visitors and residents also rely
on NC 12 for evacuation during serious storm events.
While NC 12 is recognized as an important transportation corridor, it has also long been
recognized as a threatened roadway. Beach erosion and severe storms continually decrease
the distance between NC 12 and the Atlantic Ocean. The subject section of NC 12 is
frequently subjected to overwash, flooding, and closure due to even moderate storm events.
Recently, Hurricane Dennis washed out a segment of NC 12 causing safety problems and
immediate and intensive NCDOT maintenance activities. Such storms have eliminated most
of the dune in the project area. Figure 2 displays photographs of the project area taken after a
northeaster occurred in May 2000.
B. Purpose of the Proposed Improvements
NCDOT recognizes the need for a long-term solution to provide a travel corridor that is less
vulnerable to flooding and overwash. The Department is in the process of planning studies to
implement a more long-term solution. It is also recognized, however, that any proposed
action will require substantial time to plan, design, permit, and construct. Therefore, NCDOT
is pursuing the alternatives presented in this EA as temporary short term solutions.
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C. Purpose and Need Statement
Concurrence on the project purpose and need was achieved at a NEPA/404 Merger Project
Team meeting held in Raleigh on February 25, 2000. . (The NEPA/404 Merger Project
Team is an interagency group that works together throughout the project development
process to identify key issues related to the project, minimize impacts on the environment,
and achieve consensus on certain key decision points.)
The purpose and need statement, as approved by the NEPA/404 Merger Project Team, is as
follows:
“Maintain the integrity and viability of the roadway with minimal interruption of traffic
service due to a moderate storm event between Buxton and Avon for a period of 5-10
years until a long-term solution is in place.”
Definitions of terms were presented as follows:
moderate: A Hurricane Dennis or Ash Wednesday equivalent storm
viability: “Able to safely work to restore temporary access within 48 hours and ultimately
approximately the same level of service (February 2000).”
D. Historic Resume and Project Status
In August 1991, NCDOT sponsored a research project by North Carolina State University to
identify critical sections of North Carolina’s coastal highways and options available for
maintaining these highway corridors. The study concluded that NC 12 has six critical
sections between Oregon Inlet and Ocracoke Inlet, including the proposed project area
between Buxton and Avon.
The subject portion of NC 12 has been subject to overwash for many years. Current notable
storms that have created flooding, overwash, and dune degradation at this location include
Hurricane Felix in 1995, Hurricane Bertha and Hurricane Fran in 1996, Hurricane Bonnie in
1998, and Hurricane Dennis in 1999. Several notable northeasters, such as those in May
1999 and May 2000, have been problematic for accessibility along NC 12 on Hatteras and
Ocracoke Islands. However, the subject section of NC 12 is now threatened by storms of
much less severity than hurricanes since these storms and others have eliminated the dunes
that previously provided some protection to the highway and eroded the shoreline.
A partnering agreement to address the long-term needs of NC 12 has been formulated and
adopted by the U.S. Army Corps of Engineers; U.S. Department of the Interior – National
Park Service and U.S. Fish and Wildlife Service; National Marine Fisheries Service; Federal
Highway Administration; North Carolina Department of Environment and Natural
Resources; NCDOT; Dare County; and Hyde County. The Executive Committee and
Interagency Task Force (also referred to as the Outer Banks Task Force) on the
Transportation System on North Carolina’s Outer Banks were established in October, 1993.
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The Interagency Task Force’s mission is to develop the long-range protection and
maintenance plan for the transportation system on the Outer Banks.
The intention of the Outer Banks Task Force is to complete a long-range study for NC 12 and
develop a more permanent solution for the maintenance of the transportation corridor on
Hatteras and Ocracoke Islands. Complete funding for the $8 million long-range study has
not been obtained, despite many efforts by the Outer Banks Task Force to secure funding
through various means. The Department of Transportation has funded approximately $1.5
million toward the State of North Carolina’s $4 million cost-share, but no further
commitment by federal or state agencies has been made. The continual maintenance of NC
12, however, is also a topic of conversation during Outer Banks Task Force meetings, and the
Task Force has had the opportunity to review and discuss the proposed possible interim
improvements of the subject project area. In addition to coordinating the proposed project
with the Outer Banks Task Force, NCDOT has met frequently with regulatory and resource
agencies to discuss this project and other maintenance activities along the NC 12 corridor.
At the request of these agencies, NCDOT constituted a scientific research panel of coastal
geologists and engineers in June of 1999 to study critical spots along NC 12, including the
proposed project area, and give recommendations for short-term, as well as interim
improvements. The Science Panel consisted of:
John Fisher – North Carolina State University
Margery Overton – North Carolina State University
Robert Dolan – University of Virginia
James (Tom) Jarrett – U.S. Army Corps of Engineers
Spencer Rogers – UNC Sea Grant
Stan Riggs – East Carolina University
The Science Panel identified the following measures to reduce the threat of ocean overwash
along this section of NC 12 for the long term: large scale beach re-nourishment and dune
reconstruction, the construction of a massive shoreline hardening system, construction of a
bridge, or reinstatement of ferry service. The panel recognized that these solutions may not
be viable for short-term protection. The panel’s recommended interim solution in the project
area was relocation of NC 12.
E. Characteristics of the Existing Facility
1. Benefits of NC 12 to the State, Region, and Community
Travel along this section of NC 12 is frequently hindered during and immediately
following storm events. It is the primary evacuation route for all permanent and
temporary residents of the island when severe weather is approaching. Storms frequently
cause large quantities of sand to cover the roadway and impede vehicular traffic. Loss of
the roadway would create severe emotional and economic hardship on residents
attempting to return to the island after evacuation. Because of continuing beach erosion
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and recent damage to the dune system, flooding of NC 12 is becoming a more frequent
occurrence. The permanent population of Hatteras Island relies on NC 12 for access to
the Dare County mainland. The population of Hatteras Island is approximately 4,000
persons. These residents, as well as visitors to Hatteras Island, rely on NC 12 for the
delivery of goods and services to the island. Additionally, island residents rely on off-
island community services, such as hospitals, emergency response, and waste collection.
NC 12 is their only link to the mainland. As such, NC 12 is the “lifeline” of the
community and maintenance of the corridor is extremely important to the residents of
Hatteras Island.
The principle industry of Dare County is travel and tourism. NC 12 enables both
residents and tourists to have highway access to the island communities south of the
project area. The areas south of the project area may also be accessed from the mainland
by taking ferries from the mainland to Ocracoke Island and from Ocracoke Island to
Hatteras Island.
2. Length of Roadway Studied
The length of the roadway studied is approximately 12,000 feet (3,658 meters). This
portion of roadway extends from the village of Buxton northward to the vicinity of the
Buxton/Canadian Hole parking lot on the west side of NC 12.
3. Route Classification
NC 12 is functionally classified as a major collector route and is part of the National
Highway System as an intermodal connector.
4. Existing Cross Section and Grade of Roadway
NC 12 is a two-lane road with 11-foot (3.4 meters) wide travel lanes and 5-foot (1.5
meter) paved shoulders on each side.
The elevation of the existing roadway through the project area varies from a low of 5.3
feet (1.6 meters)above msl to a high of 8.1 feet (2.5 meters) above msl. At the southern
end of the project area (south of the previously relocated section of NC 12), the roadway
averages about 6.4 feet (2.0 meters) above msl. Through the portion of road that was
relocated in 1999, the average elevation of the highway is 7.3 feet (2.2 meters) above
msl. North of the relocated roadway to a point near the parking lot at Buxton/Canadian
Hole, the road averages 5.8 feet (1.8 meters) above msl.
5. Right-of-way
Through the project area, NC 12 is located within a right-of-way easement through the
Cape Hatteras National Seashore. Based on information provided by NCDOT’s Right-of-
Way Branch this right-of-way varies from 60 feet (18.3 meters) at the southern end of the
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project to 100 feet (30.5 meters) at the northern end of the project. Right-of-way through
the Seashore is allowed by the National Park Service for the purposes of maintaining NC
12.
6. Utilities
Water consumers in Dare County receive their water from either the County Regional
Water System, the Cape Hatteras Water Association, or from private wells. Each system
obtains its raw water from discrete, yet interrelated, water sources. A water line is
located along the eastern side of NC 12 in the project area where the road has already
been relocated and along the western side in areas to the north and south of the relocated
roadway.
In Dare County, the treatment and disposal of sewage is handled by one of three methods:
a municipal sewage treatment plant in Manteo, septic tanks, or package sewage plants.
For the unincorporated parts of Dare County, including Hatteras Island, conventional
septic tanks are the most common method of sewage disposal. No sewage lines are
located within the project limits.
Dare County and its municipalities provide facilities and services for the disposal of solid
waste for both residential and commercial properties. The county also provides services
to the unincorporated areas, including Hatteras Island.
Power to Hatteras Island is provided by Cape Hatteras Electric Membership Corporation.
Overhead power lines are located in the project area.
Telephone services are provided by Sprint, which maintains two buried fiber-optic cables
along the existing roadway.
7. Speed Limit
The speed limit through the project is 55 miles (88.5 kilometers) per hour (with a 45-mph
(72.4 kmph) advisory in the relocated area).
8. Access Control
There is no control of access along the project.
9. Degree of Roadside Development
A National Park Service parking lot is located west of NC 12 at the northern end of the
project area.
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10. Flooding and Erosion
This section of NC 12 has been subject to overwash for many years. Five hurricanes
since 1995 (Felix –1995, Bertha – 1996, Fran – 1996, Bonnie – 1998, and Dennis – 1999)
have all flooded this section of NC 12. Because of the severe erosion that has occurred,
less severe storms now flood NC 12 from the ocean in the project area, rendering it
impassable. This dangerous condition is only expected to worsen in the future.
Frontal assault by storms originating seaward of the barrier islands are not the only threat
to disruption of traffic and essential services to communities south of Whalebone
Junction (the northern end of the Cape Hatteras National Seashore). Passage of low
pressure centers west of the barrier islands can also generate high tide elevations in the
sound along the back side of the island that inundate the highway. In the past ten years,
there have been at least three sound side storm events that have caused disruption of
traffic and damage to private properties. These storms include:
March, 1993 – Described at the time as the “Storm of the Century” at an
elevation 5 feet (1.5 meters) above msl
September, 1993 – Hurricane Emily at elevation 8 feet (2.4 meters) msl
October, 1994 – Storm at elevation 5.5 feet (1.7 meters) msl
Sound side storm flooding typically does not result in damage or loss of highway
pavement structure where the roadway elevation approximates the local topography.
However, disruption of traffic service does result from the inundation of the highway and
the deposition of sand associated with the presence of floodwaters.
11. Coastal Considerations and Highway Vulnerability
NC 12 is located along the Outer Banks, running from Corolla to Ocracoke, parallel, and
in many cases, very close to the Atlantic Ocean. From Oregon Inlet south, a sandy beach
and one to two rows of dunes separate the highway from the ocean. These dunes range in
elevation from a few feet/meters to as much as 20 feet (6.1 meters) above the elevation of
the road. The road itself is only 4 feet (1.2 meters) to 6 feet (1.8 meters) above sea level.
The ocean shoreline adjacent to NC 12 has a long history of erosion. The rates of
shoreline retreat range from a few feet/meters per year to as high as 15 feet (4.6 meters)
per year along this coast. As the shoreline retreats, the dunes are lost, and portions of NC
12 become exposed to storm waves and overwash. It is not unusual for beach sand to be
deposited on the highway in some locations during a storm, and in extreme events for a
portion of the highway to be damaged.
A vulnerability analysis on NC 12 was performed for the portion of road in the project
area, in addition to the three “hot spots” north of the project site on Hatteras Island.
These areas are often referred to as the “hot spots” as they are current areas of concern
with regard to beach and dune erosion and highway vulnerability. The “hot spots” to the
north of the project area were reviewed to provide relative information on these four hot
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spots. In the event a “hot spot” to the north is deemed more vulnerable or susceptible to
severe damage due to a moderate storm event, the ability for NC 12 to serve as a
connection to the north would be jeopardized.
The four specific locations analyzed are: Buxton, Rodanthe, Sandbag Area (between
Rodanthe and Pea Island) and the Canal Area (the northern end of Pea Island). These “hot
spots,” in addition to the other hot spots on Hatteras and Ocracoke Island, are shown on
Figure 3.
Objectives of “Vulnerability Analysis”. The primary objective of the study was to
determine the current vulnerability of NC 12 to damage from coastal storms in the area
between Buxton and Avon. Vulnerability has been defined by NCDOT as meaning a loss
in “integrity and viability of the roadway” or anything more than “minimal interruption
of traffic service due to a moderate storm event”. This vulnerability was to be
determined for a 5-10 year period. For the purposes of the study, it was understood that
NCDOT is developing alternatives for the long-term viability of the highway corridor
that will significantly reduce the vulnerability to storm damage; it is further understood
that one of these alternatives will be in place within approximately 10 years.
Initially, the “moderate storm” was defined as a hurricane comparable to Hurricane
Dennis or a winter northeaster (nor’easter) comparable to the Ash Wednesday Storm of
1962. However, it was later determined that the latter storm was really more intense than
“moderate” and the 1992 Halloween Storm (the Perfect Storm) was substituted for the
winter storm in this analysis.
In order to evaluate the vulnerability of NC 12, a two-dimensional analysis was made of
the combined effects of long-term shoreline erosion and the impacts of individual severe
storms. This analysis attempted to model the changes that might be expected to occur at
a number of different locations along the study area over a 5- to 7-year period. The
analysis includes a discussion of the use of man-made dunes, road relocation, and beach
nourishment to reduce vulnerability.
Study Methodology. There are a number of basic dimensions that contribute to the
overall vulnerability of the highway. These include: the width of the beach; the size of
the dunes, including both the height and width; the position of the dune relative to the
road; and the elevation of the road. In general, one can assume that areas with small
dunes and narrow beaches will be more prone to overwash and subsequent road damage
than areas with wide beaches and large dunes. These relationships are complicated due
to their three dimensional nature, the rate of shoreline retreat, and the intensity of the
storm.
The approach used in this study was a relatively simple combination of shoreline erosion
for a single storm, as determined from a well-known computer model (SBEACH) and
long-term shoreline change determined from previously collected data. The time-line
used in the study was specified by NCDOT. Starting with the year 2000, the shoreline
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was eroded back at the long-term annual rate. At the beginning of 2001 the computer
simulation of Hurricane Dennis was run, followed by four more years of long-term
erosion. At the beginning of 2005 the impacts of the Halloween Storm were modeled,
followed by two more years of erosion. In many cases it was not necessary to add the
final two years of erosion, as a conclusion regarding the vulnerability at the site could
already be determined.
The model used to simulate the impacts of a single storm was developed for the U. S.
Army Corps of Engineers. SBEACH (Storm-Induced Beach Change) is one of a handful
of models that are currently being used by coastal engineers to determine shoreline
changes due to storms. In general, the model was developed from a combination of basic
principles of sediment transport in the nearshore and extensive field and laboratory data.
As with any computer model for a very complex process, the model makes a number of
simplifying assumptions in order to reduce the complexities of the physical processes.
The data needed to run SBEACH includes a description of the storm, the beach and
nearshore geometry, and the characteristics of the sediment. The storm data includes
time-varying details of the waves, tide, and surge. In the present study, the storm data is
taken from the U. S. Army Corps of Engineers’ Field Research Facility (FRF) located at
Duck, NC. The presence of the FRF, only about 50 miles (80.5 kilometers) north of the
study site, means that excellent storm data are available as input to the SBEACH model.
The profile data needed as input to SBEACH extends from the landward point of interest
offshore to the position where no significant sediment transport is expected to occur for
the storm in question. Profile data for this study was obtained from several sources,
including field surveys, digital terrain models, and bathymetric surveys. The digital
terrain models were obtained from NCDOT. The Wilmington District of the U.S. Army
Corps of Engineers provided the bathymetry. Field survey data taken by NCDOT were
also included in the analysis.
The SBEACH model was successfully calibrated with profile data before and after
Hurricane Dennis using a transect just north of the recently relocated NC 12 in the
Buxton area. The calibration results suggest that the model slightly overestimated the
beach and dune erosion from the storm. In general, the results are reasonable when one
considers the complexity of the actual erosion processes and the relative accuracy and
timing of the measured profiles. A sensitivity analysis was undertaken of the key model
input parameters and results indicated that the model was not overly sensitive to user
specified values for these parameters.
The long-term erosion rates used in the seven-year time-line were adopted from the
erosion rates published by the N.C. Division of Coastal Management. These rates are
based upon 1992 shoreline positions.
Results for the Study Area. The model results for the Buxton area indicate that NC 12 is
highly vulnerable both to the north and the south of the recently relocated road section.
Unless some action is taken, it is reasonable to assume that during the next seven years,
the combination of a few large storms and persistent long-term erosion will continue to
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threaten the highway. The current dunes that survived Hurricane Dennis will be
destroyed and large-scale overwash will occur during periods of high waves and tide.
The portion of NC 12 that was relocated after Hurricane Dennis appears to be far less
vulnerable.
The options evaluated for reducing the relative vulnerability in the Buxton area included
the construction of protective dunes without relocating the road, beach nourishment, and
a combination of road relocation and dune construction. Indirectly, the options of
sandbag barriers and sheet pile barriers were also reviewed.
The analysis suggests that the construction of protective dunes without road relocation is
not viable due to the relatively short distance between the highway and the shoreline.
Likewise, the use of sheet piles or sandbags without moving the road will also be of
marginal and short-lived utility. As such, the NEPA/404 Project Team eliminated these
alternatives from further consideration.
Beach nourishment was shown to be a viable option for protecting the road in its present
position. The beach nourishment option reviewed included an approximately 100-foot
(30.5 meters) wide dry beach and a protective dune.
The final option considered was a combination of road relocation and protective dune
construction. The analysis indicated that a dune approximately 15 feet (4.6 meters) wide
at the crest, with an elevation of 15 feet (4.6 meters) above grade (or approximately +21
feet (6.4 meters) national geodetic vertical datum (NGVD)) would be sufficient to protect
the relocated road for the seven year time-line analyzed.
Results for the “Hot Spots” north of the Project Area. The SBEACH analysis of the
Rodanthe, Sandbag, and Canal areas indicate that, in many respects, these areas are
equally as vulnerable as the Buxton area. While the highway is not immediately
threatened, during the next seven years there will continue to be periods when storms
deposit large quantities of sand on the road. Thus, there will be substantial disruption in
service and major expenses incurred in the removal of this sand. Of the three northern
“hot spots,” the Canal Zone is the one where some action should be taken first. While
the dunes at this site are substantial, the distance from the centerline of the road to the
shoreline is relatively narrow. The model results suggest that the dunes at this site will
not last through the seven-year time-line, and the road will probably have to be relocated
in order to build new protective dunes.
The distances from the shoreline to NC 12 at the Sandbag and Rodanthe areas are
considerably greater than at the Canal Zone. At both of these sites, the SBEACH model
predicts substantial overwash if the repeat of the Halloween Storm were to occur in Year
2005. While the road will be buried in sand, there does not appear to be a threat of
undermining. There will be ample time between now and this future problem to build
new protective dunes, provided the storm events play out as modeled in this analysis.
13
The relatively large distance between the shoreline and the current position of NC 12
suggests that this future dune construction will be a practical alternative.
Taken as a whole, the results of this study suggest that NCDOT needs to consider the
entire NC 12 corridor between Oregon Inlet and Buxton as a single system. The attention
and proposed activities for the Buxton area will only reduce the storm vulnerability in
this area. It is clear that the exposure to overwash at the Rodanthe area is just as great as
that at Buxton. While it does not appear that the highway in the Rodanthe area is likely
to be damaged (assuming the level of storms analyzed), the excessive overwash will
severely restrict access until this sand is removed. In addition, some remedial action will
probably have to be taken in the Canal Zone area over the course of the next seven years.
A summary of the vulnerability study results is shown below in Table 1. It is important
to note that these results are based on a period of seven (7) years with a sample storm
scenario. For the purposes of this table, “Substantial” amounts of sand on the roadway is
defined as more than about two (2) feet (0.6 meters) of sand on the roadway.
TABLE 1. RESULTS OF VULNERABILITY ANALYSIS
(WITHOUT IMPROVEMENTS TO NC 12)
Possible Damage to Possible Substantial
Hot Spot Roadway Amounts of Sand on
Roadway
Buxton (Project Site) Yes Yes
Rodanthe No Yes
Sandbag Area No No
Canal Area Yes Yes
Due to the vulnerability of other sites along NC 12, the NCDOT has begun planning and
environmental studies for all of the other five “hot spots” on Hatteras and Ocracoke
Island. This includes studies for the Canal Area where the above analysis indicates the
possible loss of NC 12 under the given storm scenario. A description of the projects
underway to address these “hot spots” in the near-term and long-term are described
below in “Other Transportation-Related Projects in the Vicinity.”
12. Shoreline Processes
The project area is a part of the exposed “Outer Banks” barrier island coastline. The
nature of these islands is to be continually reshaped by waves, currents, and winds. The
most dramatic changes occur in response to storms that frequent the area either as
northeasters or hurricanes. More subtle changes result from the slow gradual rise in sea
level, which steadily increases the erosional pressure in the area. During storm events the
project area is frequently overwashed resulting in flooding of the highway and loss of
traffic services.
14
Wave information that is pertinent to the Cape Hatteras area is available from the Wave
Information Study (WIS) conducted by the U. S. Army Corps of Engineers, Waterways
Experiment Station (Jensen, 1983). The WIS Phase III hindcast data provides wave
height, period and direction based on 20 years (1956 thru 1975) of meteorological data.
The wave data are generated using historical pressure and wind fields to hindcast waves
in deep water. The waves are then transformed into shallow water (10 meter water
depths) for individual 10-mile (16.1 kilometer) segments along the coast.
The WIS shoreline location applicable to this area is a 10-mile (16.1 kilometer) segment
centered about 2 miles (3.2 kilometers) south of Avon. Wave height information for this
location is given in Tables 2 and 3. Table 2 provides a summary of the mean significant
wave height for each month for all years 1956 to 1975. The table also provides a mean
monthly value and a mean yearly value of significant wave height. The mean for all
years for the Cape Hatteras location is 2.2 feet (0.7 meters). These data also show the
seasonal variation with the summer months, June through August having the lowest wave
heights. Table 3 provides the largest significant wave height hindcast for each month in
each year of record. The largest significant wave height for all 20 years was 16.7 feet
(5.1 meters), which accompanied the great “Ash Wednesday Storm” of March 6-8, 1962.
This storm opened an inlet at the project site.
TABLE 2. MEAN SIGNIFICANT WAVE HEIGHTS (FEET)*
BY MONTH AND YEAR FOR CAPE HATTERAS, NORTH CAROLINA
(*multiply feet by 0.3048 to convert to meters)
MONTH
YEAR
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MEAN
1956 3.0 2.3 2.0 2.0 2.3 2.6 1.6 1.6 2.6 5.2 5.2 2.6 2.6
1957 2.3 3.0 2.6 1.6 2.3 2.0 1.6 2.0 2.0 3.6 2.3 2.3 2.3
1958 2.0 1.3 2.3 3.0 2.0 1.6 1.3 2.0 2.0 4.6 2.3 3.0 2.3
1959 1.6 2.6 2.3 2.0 1.6 1.0 2.0 1.3 2.6 3.0 3.0 2.3 2.0
1960 2.0 2.6 2.3 2.0 2.3 2.3 2.0 2.0 3.0 2.3 2.3 2.0 2.3
1961 1.6 2.6 3.0 2.0 2.6 2.0 1.0 2.0 2.6 3.3 2.0 1.3 2.3
1962 2.6 3.0 3.6 2.0 2.0 2.3 2.6 2.3 2.3 2.3 3.9 4.9 3.0
1963 2.3 3.6 2.0 1.3 2.3 1.6 1.0 1.3 3.3 3.9 1.6 1.6 2.3
1964 2.3 1.6 2.0 2.3 2.3 1.6 2.0 2.3 4.3 6.6 5.2 4.3 3.0
1965 3.0 2.6 2.3 2.0 1.3 2.0 1.6 1.3 2.6 3.3 2.3 1.3 2.3
1966 2.6 2.6 2.0 1.6 2.3 2.3 1.6 2.0 2.0 3.0 3.6 3.0 2.3
1967 2.0 2.3 2.6 2.0 2.3 3.0 1.6 2.3 3.3 2.3 1.6 2.3 2.3
1968 3.3 2.3 1.3 1.6 1.3 1.0 0.7 0.7 0.7 1.3 1.0 1.3 1.3
1969 2.6 3.3 2.0 2.0 2.3 1.6 1.3 2.3 3.0 3.6 3.0 1.6 2.3
1970 2.0 3.3 2.3 2.3 2.0 2.0 2.0 1.6 1.3 3.9 3.0 2.0 2.3
1971 2.0 2.0 2.0 1.6 1.6 1.0 2.0 2.3 3.0 3.9 2.6 3.9 2.3
1972 2.3 3.0 2.3 2.0 3.3 2.3 1.6 2.0 2.3 3.6 2.6 2.3 2.6
1973 2.3 3.6 3.3 1.6 1.6 1.6 0.7 1.0 1.3 2.6 1.3 3.3 2.0
1974 2.0 2.3 2.0 1.6 1.0 1.0 0.7 1.0 1.6 2.0 1.6 1.6 1.6
1975 2.0 3.0 2.0 1.3 1.0 1.3 2.3 0.7 2.0 2.0 2.0 2.3 2.0
MEAN 2.3 2.6 2.3 2.0 2.0 1.6 1.6 1.6 2.3 3.3 2.6 2.6 2.3
15
TABLE 3. LARGEST SIGNIFICANT WAVE HEIGHTS (FEET)*
BY MONTH AND YEAR FOR CAPE HATTERAS, NORTH CAROLINA
(*multiply feet by 0.3048 to convert to meters)
MONTH
YEAR
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1956 9.8 6.9 5.6 7.9 7.5 6.9 3.9 4.9 7.9 14.4 10.2 5.9
1957 7.9 9.2 7.5 7.2 7.2 8.5 4.9 7.9 7.9 10.2 7.2 7.2
1958 7.5 7.2 7.9 9.8 6.9 4.3 3.0 6.6 6.9 12.8 8.2 9.5
1959 5.6 7.5 7.5 7.9 4.3 3.3 6.9 4.6 7.2 8.9 6.6 7.9
1960 10.2 11.8 8.2 6.9 6.9 4.9 6.2 7.2 6.9 7.5 7.5 8.9
1961 6.6 10.5 8.9 7.9 6.9 6.6 4.9 5.9 9.2 9.2 6.9 7.2
1962 8.2 7.9 16.7 6.9 4.3 8.5 7.9 7.2 8.2 9.2 15.1 13.8
1963 6.6 10.2 6.6 7.9 6.2 8.5 3.0 3.3 8.2 11.5 6.9 8.5
1964 9.5 7.2 6.9 7.5 10.2 6.6 4.6 7.2 9.8 9.8 8.5 7.9
1965 5.6 8.2 6.6 5.2 3.3 6.9 7.2 4.3 7.5 9.8 4.9 4.9
1966 10.5 8.2 7.2 4.9 5.6 10.2 4.9 5.6 7.9 8.5 7.2 8.2
1967 7.2 8.2 4.9 6.6 7.9 8.5 4.6 4.9 7.9 5.2 6.2 8.5
1968 10.2 8.5 6.6 4.9 7.2 3.0 2.6 3.9 2.3 5.6 5.2 7.2
1969 8.5 11.2 8.5 4.9 6.9 4.9 4.3 4.6 7.9 8.5 11.8 8.9
1970 8.9 8.2 7.5 6.6 6.6 8.2 4.6 7.2 3.6 10.8 9.2 8.9
1971 7.2 7.2 9.5 8.2 7.2 4.3 7.9 7.5 10.8 10.8 7.5 9.5
1972 7.5 9.2 6.6 5.9 10.8 7.9 6.6 5.2 6.6 8.2 8.5 7.5
1973 8.5 12.8 8.9 6.6 6.6 5.2 2.6 3.3 5.6 6.6 5.9 11.8
1974 7.5 8.2 7.5 5.2 4.6 4.3 2.6 3.3 7.9 7.2 7.5 8.9
1975 7.9 8.5 8.5 6.2 3.0 5.9 10.2 3.0 7.2 6.6 8.2 6.9
LARGEST WAVE HEIGHT FOR CAPE HATTERAS = 16.7 FEET (5.1 meters)
16
In the project area the highest percent of waves arrive from the northeasterly (28 percent)
and southeasterly (25 percent) directions. However a greater percentage of larger waves
are seen to arrive from the eastern and northeastern direction, resulting in a greater
amount of wave energy emanating from these directions. Variation of the ocean water
level at Cape Hatteras is the result of the combination of both astronomical and
meteorological effects. Astronomical tides are semi-diurnal with a mean and spring
range of 3.6 and 4.3 feet (1.1 to 1.3 meters), respectively. Deviations from these periodic
tidal changes are due to meteorological disturbances, the greatest deviations being caused
by hurricanes and northeasters.
Shoreline change and erosion rate information for the Cape Hatteras area is available
from a study comparing historic charts dating back to 1852 through 1980, along the
barrier island coast from Cape Henry, Virginia, to just west of Cape Hatteras, by Everts,
et. Al., 1983. The comparative shorelines from this study for the vicinity of the project
indicates the general long-term trend for the area is erosion occurring along the east-
facing beaches north of the cape and accretion occurring west of the cape along the
south-facing beaches. The tip of the cape itself has shown a great deal of variability, but
has a general southwestward trend. This general trend in the shoreline and cape
movement is being driven by the dominance of wave energy arriving from the northeast
coupled with the long-term slow rise in sea level. The historic response of Cape Hatteras,
with erosion of the eastern shore and corresponding accretion to the south, can be
expected to continue in the future, thus representing a persistent problem. The shoreline
in the project vicinity has retreated approximately 2,500 feet (762 meters) between 1852
and 1980. This represents an average erosion rate of 19.5 feet (5.9 meters) per year over
the 128-year period.
Inman and Dolan (1989) have reported the existence of a net southward transport of sand
along the Outer Banks from Cape Hatteras to False Cape, near the Virginia/North
Carolina border. North of False Cape a reversal occurs with a net northward sand
transport existing northward to Cape Henry, Virginia.
Sediment transport values in the project area are shown on Table 4 below. The chart
includes the annual northward component (-), the annual southward component (+), the
gross transport value (the sum of northward and southward components) and the net
transport value (the difference between the northward and southward components). The
results show that on the average 555,000 cubic yards (424,328 cubic meters) are
transported northward along this shoreline reach each year along with a southward
transport of 1,270,000 cubic yards (970,985 cubic meters). It follows that the average net
transport is 715,000 cubic yards (546,657 cubic meters) to the south. Likewise, the total
average amount of sediment moving along the shoreline (annual gross transport) is
1,825,000 cubic yards (1,395,313 cubic meters).
The average values indicate that the southern potential transport is about 2.3 times the
northward transport. This is a result of the dominant wave energy arriving out of the
northeast quadrant along this region of the coast, coupled with the effective wave
17
sheltering from the south-southeast due to the presence of Diamond Shoals. The chart
also reveals a net southerly transport for each of the 20 years of record (i.e., no drift
reversals), although this value is seen to vary over a wide range. Since the values
reported are for the entire year, the seasonal changes in transport are not revealed in the
table. However, based on observation of the site over the years, a seasonal variation is
known to occur. A typical observed shoreline response is for the groin field (south of the
project area) to accrete during the summer and early fall, and erode in the late fall
through the winter and early spring. This typical shoreline change reflects the seasonal
change in longshore sediment transport, with northerly transport prevailing during the
warmer months and southerly transport occurring during the colder seasons.
TABLE 4. ANNUAL SEDIMENT TRANSPORT RATES (CY/YR)
CAPE HATTERAS (WIS STA 87)
Year Northward Southward Gross Net
1956 -383,000 1,740,000 2,123,000 1,357,000
1957 -611,000 1,236,000 1,847,000 625,000
1958 -819,000 1,152,000 1,971,000 333,000
1959 -483,000 875,000 1,358,000 392,000
1960 -573,000 1,189,000 1,762,000 616,000
1961 -666,000 1,044,000 1,710,000 378,000
1962 -681,000 2,851,000 3,532,000 2,170,000
1963 -419,000 1,360,000 1,779,000 941,000
1964 -602,000 1,779,000 2,381,000 1,177,000
1965 -331,000 1,100,000 1,431,000 769,000
1966 -661,000 1,120,000 1,781,000 459,000
1967 -518,000 1,087,000 1,605,000 569,000
1968 -267,000 634,000 901,000 367,000
1969 -685,000 1,543,000 2,228,000 858,000
1970 -726,000 935,000 1,661,000 209,000
1971 -651,000 1,237,000 1,888,000 586,000
1972 -680,000 1,452,000 2,132,000 772,000
1973 -772,000 1,308,000 2,080,000 536,000
1974 -334,000 610,000 944,000 276,000
1975 -235,000 1,154,000 1,389,000 919,000
Average -555,000 1,270,000 1,825,000 715,000
18
13. Sand Compatibility and Contaminants
Some minimal sampling has been conducted for the off-shore borrow site associated with
the Beach Nourishment alternative (Alternative 2). Preliminary analyses indicate this
material is likely to be suitable for beach fill. If the beach nourishment alternative is
selected for implementation, additional analyses will be performed to assess its
compatibility.
A potential sand source for dune construction is an upland site near Avon, referred to as
the “Hollowell” mining site. A grain-size analysis has been performed on samples from
this site, and the sand has been determined to be compatible for use for dune construction
and sand cover for sandbags. The National Park Service and US Fish and Wildlife
Service have concurred with these findings.
During its collection of soil samples for grain size analysis, NCDOT’s Geotechnical Unit
performed a site reconnaissance of the “Hollowell” mining site, one possible upland sand
source, to determine the likelihood of contaminants such as petroleum and chlorinated
solvents. Nothing was observed that would suggest the presence of any contaminants.
No unpermitted dump sites were found on the property and no examples of stained or
odorous soils were encountered. An electronic Geographic Information System (GIS)
search of NC Department of Environment and Natural Resources regulatory files did not
detect any known contaminated properties adjacent to the subject property. The nearest
such site, containing petroleum contamination, is located approximately 0.9 mile (1.4
kilometers) north along NC 12. Based upon information gathered during the field
reconnaissance and regulatory file review, NCDOT does not anticipate the presence of
any hazardous materials or petroleum within the boundaries of the Hollowell property.
14. Other Transportation-Related Projects in the Vicinity
Several interim and long-term planning projects are underway for the “hot spots” on
Hatteras and Ocracoke Islands to address transportation access provided by NC 12. A
summary of those studies is provided below.
Planning and environmental studies are currently underway for the projects listed below.
These studies will clearly define the purpose and need of the project, the range of
alternatives, and assess potential impacts resulting from implementation of the
alternatives. The alternatives being developed are intended to provide a useful life of no
less than 20 years and are termed “interim” improvements. The projects, as identified in
NCDOT’s Transportation Improvement Program (TIP), are as follows:
R-3116 A - Ocracoke Island
NC 12 from 0.5 mile (0.8 kilometers) south of Hatteras ferry terminal extending 4.0
miles (6.4 kilometers) southward on Ocracoke Island in Hyde County (4.0 miles (6.4
kilometers)).
19
R-3116 B - Hatteras Village
NC 12 from SR 1272 in Hatteras Village extending northward to second National
Park Service parking lot on east side of NC 12 in Dare County (1.7 mile ( 2.7
kilometers)).
R-3116 D - “Rodanthe „S‟ Curves”
NC 12 from SR 1492 in Rodanthe extending northward to approximately 2.0 miles
(3.2 kilometers) north of SR 1495 in Dare County
R-3116 E - “Old Sandbag Area”
NC 12 from 0.25 mile (0.4 kilometers) north of Visitor’s Center at Pea Island
National Wildlife Refuge (PINWR) south to near PINWR Ranger Station in Dare
County (2.6 miles (4.2 kilometers)).
R-3116F - “Canal Area” - Northern Pea Island
NC 12 from Oregon Inlet to northern end of freshwater ponds at Pea Island National
Wildlife Refuge in Dare County (2.5 miles (4.0 kilometers)).
Since the proposed project between Avon and Buxton (the subject of this Environmental
Assessment) only seeks temporary measures to maintain the highway corridor through
the project area for a period of 10 years, the planning, design, permitting, and
implementation of a long-term alternative must be completed before the year 2010. As
such, NCDOT has already begun planning and environmental studies to evaluate possible
long-term alternatives for the Avon to Buxton corridor. These alternatives are intended
to last for a minimum timeframe of 50 years. This project is identified in NCDOT’s TIP
as R-4070.
NCDOT recognizes the long-term maintenance of transportation along Hatteras and
Ocracoke is critical to the sustainability and economic prosperity of the communities on
Hatteras and Ocracoke Islands. Likewise, there are many environmentally sensitive
resources that are located on or near the Outer Banks that are also key to these islands’
sustainability and deserve careful consideration and protection. In an effort to provide
transportation access in an environmentally responsible manner, nine federal, state and
local agencies formed a partnership in 1993 in a collaborative effort to meet the
transportation needs on the Outer Banks while preserving the environment. Additional
information about this partnership is provided in this Environmental Assessment above
under “Historic Resume and Project Status.” This project is included in NCDOT’s TIP
as R-3116.
15. Traffic Data
On average, approximately 9000 vehicles per day (vpd) currently travel the project
section of NC 12. Peak season traffic flows are substantially higher than the average
daily traffic (ADT). It is estimated that peak season daily flows average about 13,500
20
vpd. The truck traffic is about 6%, including 1% tractor trailers and 5% dual-tired
vehicles.
By the year 2020, traffic on NC 12 is estimated to be 15,300 vpd.
III. ALTERNATIVES UNDER CONSIDERATION
The range of alternatives to be examined and evaluated to meet the project purpose and need was
selected by the NEPA/404 Merger Project Team during a NEPA/404 Merger Meeting held in
Raleigh on February 25, 2000. There was agency consensus on which alternatives would be
examined and evaluated.
Concurrent with analysis and planning for these alternatives, a vulnerability analysis of all of the
flood prone portions of NC 12 along the Outer Banks was performed by North Carolina State
University. The results of the study are summarized above under “Coastal Conditions and
Highway Vulnerability.”
As a part of the vulnerability analysis, an optimal dune size to withstand the storm climate of the
area for the project life (5 to 10 years) was estimated. The dimensions of this dune were
determined to be 15 feet (4.6 meters) above ground elevation (+21 feet (6.4 meters) NGVD) with
a 15-foot (4.6 meters) wide crest. A typical section of this dune is shown on Plates P-2, P-4, P-5,
P-6, and P-7. With optimum dune side slopes, the total footprint of this feature is 150 feet (45.7
meters) wide. Once the optimal dune size was determined, each of the alternatives above was
modified so that all plans carried the same sized dune feature.
Because of the base width of the optimal dune, Alternatives 3, 4, and 10, which use the existing
NC 12 road alignment, were deemed infeasible. If the optimal dune were placed along the
existing roadway, its seaward edge would be in the surf zone, leading to extremely high erosion
rates and unacceptable maintenance costs. Smaller sized dunes along this alignment could be
kept out of the surf zone but they would not provide the level of protection to the highway
adequate to meet the project purpose and need. Accordingly, the NEPA/404 Project Team
reconvened on June 20, 2000 and determined that Alternatives 3, 4, and 10 should be eliminated
from further consideration.
Seven major alternatives remain under consideration as described below.
Alternative 1: No-build – existing maintenance continues
Alternative 2: Existing road location – with beach nourishment
Alternative 5: Roadway relocation
Alternative 6: Roadway relocation – with a dune
Alternative 7: Roadway relocation – with subsurface sandbags and a dune
Alternative 8: Roadway relocation – with sheet piling and a dune
Alternative 9: Roadway relocation – with surface sandbags and sand covering
21
Other alternatives that were previously considered but eliminated from further consideration are
briefly discussed following the descriptions of the above alternatives. Impacts on the human and
natural environment of each alternative still under consideration are discussed in Section V.
A. Alternative 1 – “No-Build” Alternative
Under this alternative, the highway would be maintained at its existing location and
maintenance would continue on an “as needed” basis. The existing highway is shown in plan
view and typical section on Plate P-1. Maintenance would consist of removing sand from the
highway, repaving washed-out sections of roadway, and rebuilding dunes. Sand to rebuild
the dunes would come from the highway right-of-way and/or offsite sources. Maintenance
frequency would be almost entirely dependent on storm frequency and severity. Based on
recent storm history, traffic interruptions are expected to be frequent. Traffic interruptions of
7 to 8 days duration would be expected following moderate storm events. More substantial
delays would be expected following severe storm conditions.
Because of the extreme vulnerability of the highway under existing conditions, frequent
disruptions of traffic and substantial delays in reestablishing traffic flow would be anticipated
under this alternative. For these reasons, this alternative does not meet the project purpose
and need.
B. Alternative 2 – Beach Nourishment
This alternative would construct and maintain a berm and dune system seaward of the
threatened section of the highway until a long-term solution is in place. The highway would
not be relocated under this alternative.
The alignment of the berm and dune would parallel the existing shoreline and extend
between the existing dune fields located at the northern and southern ends of the project area.
(The “berm” is the nearly horizontal part of the beach that generally extends from the
seaward toe of the dune seaward to the limit of wave runup.)
Transition areas would extend for a distance of 1,500 feet (457 meters) to the north and south
and tie in with the existing 6-foot (1.8 meters) NGVD elevation.
The total length of the beach fill would be 11,050 feet (3,368 meters). The main fill would
extend approximately 8,050 feet (2,454 meters) from station 12+50 to 93+00 (metric station
3+81 to 28+35) and consists of a 15-foot (4.6 meter) high dune with a 15-foot (4.6 meter)
crest. This dune would be placed over the existing beach, which has an elevation of 6 feet
(1.8 meters) NGVD, leading to a top of dune elevation of 21 feet (6.4 meters) NGVD. The
berm fronting the dune would be 100 feet (30.5 meters) wide and would be placed at an
elevation of 6 feet (1.8 meters) NGVD. The landward slope of the dune would be 5H:1V
(horizontal to vertical) and the seaward slope would be 10H:1V. Transition areas would be
placed at the south end between stations –2+50 and 12+50 (metric stations – 0+76 and 3+81)
22
and at the north end from station 93+00 to 108+00 (metric station 28+35 to 32+92). The 6-
foot (1.8 meter) berm is an integral project feature as it protects the dune from erosion. The
dune would be stabilized by planting beach grasses such as American beach grass and bitter
panicum. The plan view and typical section of this alternative can be seen on Plate P-2.
The volume of sand needed to initially nourish the beach is 3,500,000 cubic yards (2,675,942
cubic meters). The borrow area that would be used to obtain this material is a 220-acre (89
hectares) area located approximately two miles (3.2 kilometers) offshore. Its dimensions are
approximately 3,100 feet (945 meters) long (parallel to the shoreline) by 3,100 feet (945
meters) wide. Material would be excavated to a depth of –10 feet (-3.0 meters) below the
existing bottom elevation. The proposed borrow site is shown on Plate P-8. Not all of the
area designated for borrow on this figure would be used.
Approximately 220 acres (89 hectares) would be used during initial construction of the
project and an additional 280 acres (113 hectares) would be used for obtaining maintenance
material over the 10-year life of the project. Maintenance material would also be excavated
from this site to a depth of –10 feet (-3.0 meters) below the existing bottom elevation.
Topographic surveys and subsurface investigations of the borrow area have been performed
and material from this site has been determined to be compatible with the existing beach.
Sands from this borrow area would be transported to the beach by either an ocean-certified
pipeline dredge or by a hopper dredge with direct pump out capabilities. Once placed on the
beach, the sands would be shaped into the design dune and berm system by conventional
earth moving equipment. This alternative would initially require approximately 10 months to
construct. In order to minimize impacts during the sea turtle and shorebird nesting seasons,
all sands would be placed between November 15 and March 31 to the maximum extent
practicable. However, because of the adverse wave climate normally found in the project
area during the winter months, it is probable that the majority of the initial construction work
under this alternative would be performed during these nesting seasons.
Maintenance of the project would use the same borrow source, construction methods, and
schedule as initial construction. Future maintenance would consist of periodic nourishment
with about 1,320,000 cubic yards (1,009,212 cubic meters) of sand being needed about every
3 years to replace beach fill lost to constant erosion. Additional losses due a Hurricane
Dennis equivalent storm event would be about 300,000 cubic yards (229,367 cubic meters).
Losses incurred from such an event could be incorporated into a normal renourishment cycle.
Because of the lesser quantities of material involved, maintenance events could be completed
during the November 15 – March 31 window if weather and sea conditions permit.
However, because of the unpredictability of sea conditions, weather delays could force
encroachment into the nesting seasons.
Estimated construction costs for the initial beach nourishment are $11,350,000. Estimated
costs for periodic renourishment every 3 years are $5,350,000. Estimated costs for
renourishment that include additional sand needed as a result of a Hurricane Dennis
equivalent storm event are $7,500,000.
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There are no removal costs directly associated with the Beach Nourishment Alternative as,
once abandoned, the berm and dune would erode away within 10 – 15 years, depending on
storm frequency and severity.
C. Alternative 5 – Roadway Relocation
The total length of the proposed roadway relocation alternative is approximately 2.1 miles
(3.4 kilometers). The southern segment, which begins at Buxton Village and ends at the
existing relocated section, comprises 0.55 mile (0.9 kilometers) of the total length. The
middle segment, a portion of the existing relocated section, is 0.28 mile (0.5 kilometers) of
the total length. The northern segment begins at the existing relocation and extends to the
Canadian Hole parking lot, a length of 1.25 miles (2.0 kilometers). The distance between the
alignment of the existing road and that proposed for the relocated alignment ranges from 0
feet to 200 feet ( 0 to 61 meters). The distance between the ocean and the proposed
relocation ranges from 300 feet to 500 feet (91 meters to 152 meters). The proposed right-of-
way width is 100 feet (30.5 meters). Design speed of the alternative is 55 miles (88.5
kilometers) per hour. The relocated roadway is shown on Plate P-3.
The typical section is a two-lane road with 11-foot (3.4 meters) wide lanes and 5-foot (1.5
meter) paved shoulders, for a total pavement width of 32 feet (9.8 meters). This typical
section is consistent with other portions of NC 12 on Hatteras Island. The typical section
also includes a 4-foot (1.2 meter) grass shoulder and a ditch on the eastern side of the road.
The soundside slope of the ditch is 4:1, while the ocean-side slope varies. The western side
of the relocation includes a variable slope toward the sound (see typical section Plate P-3).
The proposed alignment of the road may involve four utilities:
An overhead power line is owned by Cape Hatteras Electric Membership
Corporation. It is located on the western side of the road except along the area
already relocated. In that section it is on the eastern side.
An 8-inch (20.3 centimeter) PVC water line is owned by Dare County. It is located
along the western side of the road except along the area already relocated where it is
on the eastern side. Dare County has plans to relocate all of this line to the western
side of the road.
A fiber optic telephone line is owned by Sprint and is located along the eastern side of
NC 12. In the area that has already been relocated, the line is on the western side.
The cable television is located above ground with the powerline on the poles owned
by Cape Hatteras Electric Membership Corporation.
If the existing roadway elevation is maintained at +/- 6 feet (1.8 meters) above msl, overwash
may still occur. No wetlands would be impacted by the alignment at this elevation. There
would be no seasonal restrictions in implementing this alternative.
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Removal and restoration would follow traditional techniques: pavement removal, regrading,
and revegetating.
The estimated construction cost of the roadway relocation is $2,000,000. Removal of the old
pavement and habitat restoration costs would be about $200,000.
The existing dunes would be maintained as in the past by NCDOT. As overwash eventually
affects the highway or the highway becomes vulnerable due to the lack of dunes,
maintenance would be performed.
An evaluation of possible elevations of the roadway was conducted to determine the
“optimal” elevation to minimize ocean overwash, flooding and sand deposition on the
roadway. The existing roadway elevation is about 6 feet (1.8 meters) above msl. Three
alternative elevations were examined: + 7 feet (2.1 meters) msl, +10 feet (+3.0 meters) msl,
and +14 feet (4.3 meters) msl. Typical cross sections of these alternative elevations are
shown on Plate P-3. Each elevation would be constructed using conventional construction
techniques, and no dune or any other type of protective structure would be placed between
the relocated road and the ocean.
Each alternative elevation would use the same road width (a two-lane road with 11-foot (3.4
meters) lanes and 5-foot (1.5 meter) paved shoulders, for a total pavement width of 32 feet
(9.8 meters)). Their typical sections would also include 4-foot (1.2 meter) grass shoulders.
Only the 7-foot (2.1 meter) elevation would require below grade swales on the sides of the
road. These swales would be approximately 10 feet (3.0 meters) wide. The grassed roadside
slopes would be 4:1, regardless of the elevation selected, leading to slopes of approximately
1 foot (0.3 meter) wide for the 7-foot (2.1 meters) elevation, 16 feet (4.9 meters) wide for the
10-foot (3.0 meters) elevation, and 32 feet (9.8 meters) wide for the 14-foot (4.3 meters)
elevation.
The construction impact width and right-of-way required for construction of the highway
increase as the roadbed elevation increases. A 70-foot (21.3 meter) impact width would be
required for the 7-foot (2.1 meters) elevation, a 80-foot (24.4 meter) impact width for the 10-
foot (3.0 meters) elevation, and a 120-foot (36.6 meter) impact width for the 14-foot (4.3
meters) elevation.
Sand fill to construct the elevated roadbed would come from an upland source. Fill
quantities for the 7-foot (2.1 meters) elevation would be minimal. About 90,000 cubic yards
(68,810 cubic meters) would be required for construction of the road at the 10-foot (3.0
meters) elevation, and 210,000 cubic yards (160,557 cubic meters)would be required for
construction of the road at the 14-foot (4.3 meters) elevation. One possible sand source is the
Hollowell mining site near Avon. Standard truck hauling, placing, and shaping would be
used to construct any of the elevated roadway alternatives.
As stated above, relocating the highway at the existing 6-foot (1.8 meter) elevation or the 7-
foot (2.1 meters) elevation would result in no impacts to wetlands; relocating it at higher
25
elevations would result in greater wetland losses because of the increase in construction
width. Approximately 0.02 acre (0.008 hectares) of wetland impacts would be realized with
the footprint of the 10-foot (3.0 meters) elevation and 0.12 acre (0.049 hectares) at the 14-
foot (4.3 meters) elevation.
Construction times for the relocated highway would vary with the elevation selected. It is
estimated that it would take 6 months to relocate the road at a 7-foot (2.1 meters) elevation, 8
months at a 10-foot (3.0 meters) elevation, and 12 months at a 14-foot (4.3 meters) elevation.
There would likely be no seasonal restrictions associated with implementing any of the
proposed elevations. The number of utility poles to be relocated would also vary with
elevation. Twelve poles would have to be relocated at the 7-foot (2.1 meters) elevation, 14
poles at the 10-foot (3.0 meters) elevation, and 20 poles at the 14-foot (4.3 meters) elevation.
Placing the highway at an elevation where it is less subject to ocean overwash increases the
attack of wave energy against the base of the roadbed fill during storm events. Erosive
events that undercut the highway may force extended road closures and loss of transportation
services. Because of scour and undercutting, higher elevations may actually increase the
maintenance required to maintain the highway in an operable condition. Currently, it is
estimated that maintenance would be required 2-3 times per year to repair the dunes.
As mentioned earlier, sound side storm flooding typically does not result in damage or loss of
highway pavement structure where the roadway elevation approximates the local topography.
However, disruption of traffic service does result from the inundation of the highway and the
deposition of sand associated with the presence of floodwaters.
The cost of relocating the road at higher grades exceeds the cost of relocating it at grade
because of the extra quantities of fill that must be trucked-in, placed and shaped. Estimated
costs of relocating the road are $ 2,000,000 at the 7-foot (2.1 meters) elevation, $ 2,900,000
at the 10-foot (3.0 meters) elevation, and $ 4,100,000 at the 14-foot (4.3 meters) elevation.
Utility costs for the 7-foot, 10-foot, and 14-foot elevations are $160,000, $185,000, and
$260,000, respectively. Removal costs for the pavement ($200,000) would remain as
described previously.
D. Alternative 6 – Roadway Relocation with a Dune
Under this alternative, the highway would be relocated at grade (approximately 7 feet (2.1
meters) above msl), as previously described, and a dune would be constructed about 15 feet
(4.6 meters) seaward of the highway. The dune would be 15 feet (4.6 meters) high (21 feet
(6.4 meters) NGVD) and would have a crest width of 15 feet (4.6 meters) and a base width
that varies from 100 to 150 feet (30.5 to 45.7 meters). Side slopes would be 3H:1V on the
highway side and 5H:1V on the ocean side. Approximately 340,000 cubic yards (259,949
cubic meters) of sand will be required to construct this dune. The dune would be stabilized
by planting beach grasses such as American beach grass and bitter panicum. The dune would
be adequate to keep ocean flooding and overwash off of the highway but would not stop
26
sound-side flooding. A typical cross section and plan view of this alternative can be seen on
Plate P-4.
Sand to construct the dune would come from an upland site (possibly from the Hollowell site
– a commercial sand source located north of the project area near the community of Avon),
or from a dredged material disposal site located at Avon. Sand from the disposal site has
been tested and found to be beach compatible and free of contaminants.
This alternative would require the relocation of 35 utility poles, and the dune would cover the
waterline and fiber optic lines in some portions of the project area.
This alternative would require approximately 9 months to construct (6 months to relocate the
highway and 6 months to construct the dunes, with 3 months of overlap between the two).
The highway could be relocated at any season of the year and avoid suitable sea turtle nesting
habitat, but the majority of the dune construction would be scheduled to occur during the
winter months (November 15-March 31) to avoid the sea turtle and shorebird nesting
seasons. Work would be planned so that any dune building work outside of the winter
months would take place at the northern or southern ends of the project, where existing dunes
would provide a natural barrier between the beach and the work area.
Maintenance of this alternative is expected to be minor but would depend on storm frequency
and severity. Maintenance would consist of adding fill and re-grading the dune in areas that
are damaged. Fill to accomplish such repairs would be beach compatible and would likely
come from an upland source. Maintenance of the dunes constructed as a part of this
alternative is anticipated to be less than maintenance of the existing dunes associated with
Alternative 5 (Roadway Relocation).
Initial costs of this alternative are estimated to be $5,900,000. Of this cost, $2,000,000
would be for relocation of the road and $3,900,000 for construction of the dune. Utility
relocation costs are estimated to be $450,000. The cost of removing portions of the old
roadway is $200,000.
E. Alternative 7 – Roadway Relocation with Subsurface Sandbags and a Dune
Under this alternative, the highway would be relocated at grade (approximately 7 feet (2.1
meters) above msl), as previously described, and protective sandbags would be buried on the
ocean side of NC 12 starting just north of Buxton and continuing for 11,620 feet (3,542
meters) northward. The sandbags would be placed between 10 and 20 feet (3.0 to 6.1
meters) from the new edge of pavement and would be capped with a dune 15 feet (4.6
meters) high with a 15-foot (4.6 meters) wide crest. The sandbag core of this alternative
provides additional protection against inlet formation during extreme storm events. A typical
cross section and plan view of this alternative can be seen on Plate P-5.
The dune configuration under this alternative would be the same as described under
Alternative 6, above. The sandbag core would consist of a trapezoidal-shaped system of
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twenty sandbags eight feet (2.4 meters) high and twenty feet (6.1 meters) wide at the base.
The sandbags would be buried with the top of the sandbag protection at or near the elevation
of the existing roadway. Individual sandbags would be 2 feet (0.6 meters) high, 4 feet (1.2
meters) wide and 12 feet (3.7 meters) long. Large geotextile tubes about 8 feet (2.4 meters)
high and up to 200 feet (61 meters) long were also considered instead of sandbags. Initial
costs of geotextile tubes would be less; however, they are not redundant and a tear could
result in loss of an entire 200-foot (61-meter) section. Therefore, geotextile tubes are not
considered the preferable sandbag core treatment.
Sandbags would either be “wet-filled” by taking material from the surf zone or “dry-filled”
by taking sand from the trench being dug for their placement. Approximately 54,000 cubic
yards (41,286 cubic meters) of sand would be required to fill the sandbags and 340,000 cubic
yards (259,949 cubic meters) would be needed to construct the dune. If sand excavated to
allow placement of the sandbags is not used in the filling of the bags, it would be used as part
of the sand required for construction of the dune on top of the sandbags once their installation
is complete.
This alternative would require the relocation of 35 utility poles. Because the sandbags are
buried for this alternative, minor involvement with the water line and fiber-optic may be
required near the north and south ends of the project.
No maintenance of the sandbags is expected during 5-10 year project life. The sandbags
would be buried and there would be little chance of ultraviolet light damage or damage by
vandals. The dune covering the sandbags should protect them during storm events and keep
the top level of the sandbags from becoming exposed. Overall, maintenance of this
alternative is expected to be minor, depending on storm frequency and severity.
Maintenance would consist of adding fill and re-grading the seaward toe of the dune in areas
that are damaged by wave attack. Fill to accomplish such repairs would be beach compatible
and would come from an upland source.
This alternative would take approximately 12 months to construct if some project
components are constructed concurrently. Road relocation would require approximately 6
months, sandbag placement approximately 6 months (with 2 crews), and dune construction
would require about 6 months. Road relocation could be performed at any time of year and
would likely be performed first. Work on the sandbags and dunes would occur outside the
sea turtle nesting season to the maximum extent practicable.
Estimated construction costs for this alternative are $7,900,000; $2,000,000 to relocate the
road, $1,500,000 to place the sandbags, $3,900,000 to place the dune, and $500,000 to
relocate utilities. The cost to remove the old roadbed is $200,000.
At the end of the life of the project and once a long-term solution is in place (within ten
years), the keyed-in sandbags would be removed. This would require some excavation and
site restoration. The cost associated with removing the keyed-in sandbags is $707,000
including re-excavation for removal and restoration of the site.
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F. Alternative 8 - Roadway Relocation with Sheet Pile and a Dune
This alternative consists of relocating the highway at grade (approximately 7 feet (2.1
meters) above msl), as previously described. This alternative also includes driving 25–foot
(7.6 meter) long sheet piles along the ocean side of relocated NC 12, starting just north of
Buxton and continuing for 11,620 feet (3,542 meters) north, and capping the sheet pile
feature with a dune 15 feet (4.6 meters) high with a 15-foot (4.6 meter) crest width. The
sheet pile feature would guard against formation of an inlet at this location. The sheet pile
would be placed between 10 and 20 feet (3.0 to 6.1 meters) from the existing edge of
pavement and driven until the top of sheet pile was near the elevation of the roadway. Top of
sheet pile elevation would vary from elevation 6.0 feet (1.8 meters) to elevation 7.5 feet (2.3
meters) and it would generally be near the elevation of the adjacent ground. Where the top
elevation would be below the existing grade, the contractor would be required to excavate in
order to place the piles and backfill after pile placement. Where the top of pile would be
above the adjacent grade the contractor would be required to provide fill to cover the piles
and maintain proper drainage. Steel sheet pile proposed for this alternative would be an
AZ13 or equal (ASTM A572 GR50). Design of the sheet pile alternative was based on the
assumption that erosion seaward of the wall would extend down to elevation –2 feet (-0.6
meters) and erosion landward side would extend to elevation +2.5 feet (0.8 meters). Sheet
piles are also designed to accommodate HS20-44 truck loading on the shoulder on NC 12.
Sheet pile would be driven to depth using a pile driver or a vibratory hammer. The cross
section and plan view of this alternative can be seen on Plate P-6.
The overhead power line including 35 poles would require relocation for dune construction.
Minor involvement with the waterline and fiber optics cable near the north and south ends of
the project may be required.
The dune configuration under this alternative would be the same as described under
Alternatives 6 and 7, above.
Future maintenance of the sheet pile system should be minimal. The sheet pile will be buried
and protected from most adverse conditions. The dune feature is the only component of this
alternative that would likely require maintenance. Maintenance of the dune is expected to be
minor, depending on storm frequency and severity. Maintenance would consist of adding fill
and re-grading the seaward toe of the dune in areas that are damaged by wave attack. Fill to
accomplish such repairs would be beach compatible and would come from an upland source.
Like Alternative 7, this alternative would take approximately 12 months to construct if some
project components are constructed concurrently. Road relocation would require
approximately 6 months, sheet pile placement approximately 6 months, and dune
construction would require about 6 months. Road relocation could be performed at any time
of year and would probably be performed first. Work on the sheet pile and dunes would
occur outside the sea turtle nesting season, if possible.
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Estimated construction costs for this alternative are $9,900,000; $2,000,000 to relocate the
road, $3,500,000 to place the sheet pile, $3,900,000 to place the dune, and $500,000 to
relocate utilities. Removal of the old roadbed is estimated to cost $200,000.
All sheet pile would be removed once a long-term solution is in place. This may require
some excavation and site restoration. The cost associated with removing the sheet pile is
$1,030,000, including re-excavation of the dune for removal of the sheet pile and restoration
of the site.
G. Alternative 9 – Roadway Relocation with surface sandbags and sand cover
This alternative involves relocating the roadway and then placing a sandbag barrier to the
east of the new highway about 15 feet (4.6 meters) from the edge of the pavement.
Approximately 44 sandbags would be used in a cross section, as seen on Plate P-7. These
sandbags would be capped with a layer of sand to provide UV protection to the bags and give
a more natural appearance to the project. These bags would be placed on the existing ground
and would be “wet-filled” from the surf zone. The sandbag barrier would help protect
against the formation of a new inlet before the long-term solution is in place. It would run
the entire length of the relocated highway. Plate P-7 also shows this alternative in plan view.
Future maintenance on the sandbags would be modest. Initially, the sandbags would be
covered by a layer of sand. There will be little chance ultraviolet light damage or damage by
vandals. After a storm event or due to shifting sands the top level of sandbags may become
exposed. Life of sandbag material exposed to UV light is generally 10 years or more;
however, vandalism could significantly reduce the life or increase maintenance cost. After a
major storm that erodes sand away from the seaward side of the sandbags, sand would be
replaced to recover the bags and prevent undermining that would cause sandbag failure.
This alternative would require the relocation of 35 utility poles. Some minor involvement
with the fiber optic line and the water line may be needed.
It is currently estimated that this alternative will require approximately 18 months to
construct; 6 months to relocate the road, 12 months to place the sandbags and one month to
cover the sandbags with sand. Covering the sandbags with sand will probably occur
concurrently with sandbag placement. Roadway relocation could occur at any time of year
without disturbing sea turtles or nesting shorebirds. Because of the length of time required to
place the sandbags, this work will have to occur during the sea turtle and shorebird nesting
seasons.
Removal of this alternative would require removing and re-grading both the roadway and the
adjacent area where sandbags are placed. All disturbed areas would be replanted to hasten
the return of a natural community.
Estimated construction costs for this alternative are $10,000,000; $2,000,000 to relocate the
road, $7,000,000 to place the sandbags, $1,000,000 to place the sand covering, and $450,000
31
to relocate utilities. Removal of the old roadbed is estimated to cost $200,000. At the end of
the life of the project and once a long-term solution is in place (within ten years), the
sandbags would be removed. Costs associated with removing the sandbags is $1,500,000.
Fill material for construction of the sandbags for this alternative would come from material
from the surf zone. Initially, an excavator will excavate or level material to provide a base
for sandbag placement. Sand would be hydraulically pumped from the surf filling the bags in
place. The pump would pull a slurry of sand and water from the surf and deposits it in the
sandbags. Generally a minimum of 200 bags (740 cubic yards (566 cubic meters)) are filled
at one location prior to proceeding to the next location. After the placement of the sandbags,
sand would be placed on top of the sandbags using a front-end loader. Sand used to cover
the sandbags will come from sand excavated from the footprint of the sandbags prior to their
construction and from an upland source (possibly the Hollowell site in Avon).
H. Summary of Alternatives
A summary of the alternatives under consideration is provided below in Tables 5A through
5E. These tables provide information regarding the construction, engineering and design,
sand source, maintenance, removal, and cost considerations for each alternative.
32
ADD TABLE 5A – 5E HERE.
33
34
35
36
37
I. Other Alternatives
As stated previously, because of the width of the optimal dune, Alternatives 3, 4, and 10 that
utilize the roadway at its existing location, are no longer considered feasible and do not meet
the intended purpose of the project. If the optimal dune were placed along the existing
roadway, its seaward edge would be in the surf zone, leading to extremely high erosion rates
and maintenance costs. Smaller sized dunes along this alignment could be kept out of the
surf zone, but they would not provide a level of protection to the highway adequate to meet
the project purpose and need. Accordingly, the NEPA/404 Merger Project Team reconvened
on June 20, 2000 and determined that Alternatives 3, 4, and 10 should be dropped from
further consideration.
Shoreline Hardening.
Other shoreline hardening alternatives, such as groins or a seawall, would provide the
protection needed for the highway until a long-term solution is in place. Such alternatives
are not permitted under North Carolina’s Coastal Management Policy and are probably not
compatible with the management strategies of the Cape Hatteras National Seashore. For
these reasons, other shoreline hardening features are not considered to be viable alternatives.
Gravel Road.
Construction of a gravel road in lieu of a paved roadway surface would not provide the same
level of service or carrying capacity provided by the existing roadway. Maintenance of a
gravel roadway (pushing sand off the roadway) would also be more difficult.
Postponing Action.
Postponement of any action would permit continued jeopardy to the safety of motorists and
accessibility along this subject section of NC 12. Further erosion and degredation of the
protective dunes are anticipated, thereby making the highway more vulnerable to severe
ocean overwash, flooding, sand coverage, and possible inlet formation. Therefore,
postponing action is not recommended.
No alternative has been selected as a recommended alternative at this time. A recommended
alternative will selected by the NEPA/404 project team after it has reviewed this
Environmental Assessment and learned the views of the public from a public hearing.
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IV. SOCIAL, ECONOMIC, AND ENVIRONMENTAL IMPACTS
A. Social Environment
1. Regional Setting
The project study area lies in Dare County in the extreme northeastern part of the Lower
Coastal Plain Physiographic Province. The total area of the county is 250,105 acres (102,214
hectares) and it had a 1990 population of 22,746. The county’s major economic resources
include agriculture, forestry, commercial fishing, tourism, and recreational activities.
The study area is in the Cape Hatteras National Seashore, which stretches over 70 miles
(112.7 kilometers) along North Carolina’s barrier islands in Dare and Hyde County. The
subject section of NC 12 connects the villages of Buxton and Avon.
2. Public Facilities
None of the alternatives under consideration would permanently impact public facilities. A
public parking lot is located along NC 12 at the northern end of the study area. Regardless of
the alternative selected, temporary use of the parking lot may be necessary during
construction for staging/parking of equipment. However, access to the lot for the public will
be maintained throughout construction. If use of the parking lot as a staging area is
considered, NCDOT will coordinate with the National Park Service.
3. Relocation Impacts
None of the alternatives under consideration would result in the relocation of businesses,
homes, or public facilities. However, utility relocations may be required.
4. Cultural Resources
In terms of historic architectural resources, there are no known historic structures located
within the area of potential effect. The State Historic Preservation Office has recommended
that no historic architectural survey be conducted for this project (see correspondence in
Appendix).
Coordination with the State Historic Preservation Office indicates that there is the potential
to impact the remains of shipwrecks on the beach in the project area if beach sands are
disturbed during dune replenishment or the filling of sandbags. If an alternative is selected
that requires the disturbance of beach sands (Alternative 2, 6, 7, 8, or 9), a survey will be
conducted of the beach immediately prior to construction. Upon request, the Underwater
Archaeology Unit of the Department of Cultural Resources can perform this survey.
Equipment operators will be informed of the possibility for encountering the remains of
shipwrecks. If such remains are encountered, work will be moved to another area and the
Underwater Archaeology Unit of the State Historic Preservation Office will be contacted
39
immediately so an assessment of the wreckage can be made and the proper course of action
determined.
The project area is the site of the former Chacandepeco Inlet. This historic inlet was open
during the age of exploration but had closed by 1700. It reopened during a major storm in
1961 and was known locally as Buxton Inlet. It remained open until closed by man in 1962.
Because of the existence of an inlet in this location during the 17th century, there is a
possibility that submerged cultural resources lie in the near shore ocean bottom within the
boundaries of the area designated for obtaining borrow material for Alternative 2 (Beach
Nourishment).
If the Beach Nourishment Alternative (Alternative 2) is selected as the recommended
alternative, surveys of the offshore borrow area would be performed to determine if
submerged cultural resources are present. Because of the size of the area designated for
borrow, it should be possible to extract needed borrow material while maintaining adequate
protective buffers around any potential targets encountered. For this reason, it is believed
that the Beach Nourishment Alternative could be constructed and maintained without
adversely impacting cultural resources. The results of the borrow area survey would be
coordinated with the State Historic Preservation Officer regarding the need for further
investigations.
B. Land Use
1. Land Use Planning and Zoning
The project is located in Dare County, which has adopted the 1994 Land Use Plan. The
study area, however, is located on Federal lands that are not a focus of local government
plans. The study area is located entirely within the Cape Hatteras National Seashore, under
the jurisdiction of the Department of the Interior – National Park Service, and is not zoned or
otherwise affected by county land use and development codes.
2. Existing Land Use
No buildings are located within the study limits. A public parking lot is located along the
western side of NC 12. The remaining area consists of beach, dunes, salt marsh, and Pamlico
Sound, all of which are heavily used for recreation. “Canadian Hole,” a deepwater area that
resulted from the extraction of sand used to close Buxton Inlet in 1962, is heavily used for
boating, swimming, and fishing.
A discussion of the Cape Hatteras National Seashore is included under “Section 4(f)
Resources” in this document.
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3. Future Land Use
As stated above, Dare County does not address land use issues for Federally-owned lands in
the most recent Land Use Plan. The National Park Service has been discussing a partnership
with Dare County to install permanent bathhouse facilities at Canadian Hole. The proposed
project will not interfere with any known future land use.
4. Compatibility of Project with Local Plans
The 1994 Land Use Plan encourages development and implementation of a long-term plan
for the protection of NC 12. County policy generally supports beach access points, but does
not specify locations. There are no policies on beach nourishment, sandbags, sheet pile
installation, road relocation or dune reconstruction in the project area. All of these
alternatives are generally consistent with local plans and objectives.
Cape Hatteras National Seashore is managed by the National Park Service under guidance
provided by various statutes and management plans. Before a Special Use Permit is issued
for any alternative, the National Park Service will have to determine whether or not that
alternative is compatible with its management objectives. To date, no compatibility
determinations have been made on any alternative under consideration.
Excerpts from the National Park Service’s laws, policies, and management plans that pertain
to the project area and alternatives under consideration are cited in “Draft Section 4(f)
Evaluation” in this document.
C. Environmental Impacts
1. Biotic Communities
Beach/Sand Community
Description. The Beach/Sand Community is located east of existing NC 12, between the
dune line and the swash zone and is characterized by sand flats. Windblown sand,
temperature extremes, and salt aerosols help create a severe environment where life is
difficult for many species of plants and animals. However, a few plant species such as
beach spurge (Euphorbia polygonifolia), sea rocket (Cakile edentula), and seaside
pennywort (Hydrocotyle bonariensis) may be found growing along wrack lines and
seaside transitional zones between the beach and dune communities.
Birds are an important component of the beach community. Some species, such as the
American oystercatcher (Haematopus palliatus), brown pelican (Pelecanus occidentalis),
and a variety of gulls and terns rest and forage along the beach/open water interface.
Seasonally, large numbers of shorebirds can be seen during migration along the beaches.
The federally protected loggerhead sea turtle (Carretta carretta) is a beach nesting
species which utilizes beach and foredune habitat to the east of existing NC 12.
41
Invertebrate inhabitants of this community include the scavenging ghost crab (Ocypode
quadrata) whose burrows may be seen dotting the beach.
Because of the severe erosion being experienced in this area, little of the beach/sand
community remains. In some places, the high tide line is now at the base of the dunes.
Roughly 13.8 acres (5.6 hectares) (50-foot (15.2 meter) wide natural beach berm x
12,000-foot (3,658 meters) project length) of beach/sand community habitat exist in the
project area.
This dynamic area would be affected by any alternative selected, including the no-build
alternative. Under the no-build alternative, this area would continue to be regularly
overwashed, and would be disturbed by subsequent measures such as scraping and dune
building to reestablish highway access and reformation of protective dunes.
Impacts of Alternatives. Of all of the alternatives under consideration, the Beach
Nourishment Alternative (Alternative 2) would have the most severe impact on this
community. The beach community would be totally covered by deposited sands and,
while recovery of the biological community would begin almost immediately after the
cessation of work, there would be higher than normal erosion rates, and the area would be
repeatedly disturbed by future maintenance events until the end of the 10-year project
life. Accordingly, the natural diversity of the habitat would be depressed and the quality
of shorebird foraging in the project area will be diminished.
Offsetting these impacts would be the increase in the habitat area made available under
Alternative 2 by moving the mean high water line seaward to accommodate the design
profile. Of the 105.9-acre (42.9 hectare) project footprint for this alternative, only 27.5
acres (11.1 hectares) would be on land currently above existing mean high water,
meaning that 78.4 acres (31.7 hectares) of newly created high ground will be present. Of
that 78.4 acres (31.7 hectares), 26.4 acres (10.7 hectares) would be shaped and planted as
dune habitat, leaving a balance of 52 acres (21.0 hectares) of bare sand habitat. With
only about 13.8 acres (5.6 hectares) of this habitat present on site today, a net increase of
38.2 acres (15.5 hectares) will be realized. However, as mentioned above, this habitat
will be of lower quality than that currently existing because of high erosion rates and
repeated disturbance from renourishment activities.
The road relocation alternative (Alternative 5) would have minimal impact on this
community as it would be retreating from the beachfront and moving back into the dune
grass community. The existing roadbed would be restored by removing the old roadway
and revegetating the area. As shoreline erosion continues, the area of the existing
roadbed will eventually become part of the beachfront.
Under Alternatives 6 through 9, as above, the road relocation component would have
little impact on the beach community. However, the placement of the adjacent features,
including a dune to cover them, would cover approximately 32.1 acres (13 hectares) of
this habitat type as the footprint of the dune component of each is essentially the same.
42
Maintenance of the seaward toe of the dune under each of these alternatives would also
cause some impacts to the beach community. Disturbance would come from trucking in
sand to replace that lost after storm events and from shaping and grading the dune by
conventional earth moving equipment.
Swash Zone Community
Description. This community is found just seaward of the Sand/Beach community and is
home to a variety of fauna. Species likely to be found here include the detrital feeding
mole crab (Emerita talpoida), coquina clam (Donax variabilis), blue crab (Callinectes
sapidus), shrimp (Penaeus sp.), sand dollar (Mellita quinquiesperforata) and parchment
tube worms (Chaetopterus sp.). It can also function as a valuable nursery area for several
commercially and ecologically important species of fish. These values are discussed at
length in the “Surf Zone and Near Shore Fishes” section below.
This community exists in an environment that is constantly changing as a result of tidal
action and natural accretion and erosion events. While the members of this community
have adapted to live in a dynamic equilibrium, they can still be severely impacted by
extensive and/or repeated activities that alter their environment.
Impacts of Alternatives. The only impacts to this community that are anticipated with the
No-Build Alternative (Alternative 1) are impacts associated with maintenance of the
existing dune. Since the road is in close proximity to the active beach, dune maintenance
is anticipated to be more frequent with this alternative than the other alternatives. Such
impacts would be the result of reshaping the dunes and filling gaps and blowout areas.
The Beach Nourishment Alternative (Alternative 2) would completely cover the existing
swash zone and create a new swash zone further seaward. While this newly created
swash zone would almost immediately begin to colonize with beach organisms drifting in
from adjacent beaches, levels of diversity would be lower than background levels on
adjacent beaches for at least two years. Levels of diversity on the beach would continue
to increase with time until another beach nourishment cycle takes place. Each
nourishment event would negatively impact the swash zone fauna and other fish and
wildlife dependent on it. Given a projected nourishment cycle of 3 years, the beach in the
project area would never be allowed to fully recover before another nourishment took
place. Therefore, under the Beach Nourishment Alternative, populations of beach
organisms would be depressed for the life of the project. This depression in beach
organisms may be reflected in reduced food availability for shorebirds and fishes using
the surf zone. Once nourishment activities cease, permanent recovery should be attained
within a few years.
The road relocation alternatives would have only minor effects on this community.
Alternative 5, road relocation without any protective dune or other feature, would
probably not have any effect on the swash zone. Alternatives 6,7,8, and 9 all have dune
features that protect the relocated road and, accordingly, carry the project footprint
43
seaward. While the dune for each alternative lies above the mean high water line, normal
or storm driven erosion could cause damage to the seaward toe of the dune. If this
happens, maintenance activities such as trucking in fill and shaping and grading it would
be required. Most of these activities should occur outside of the swash zone but
depending on the severity of erosion, disturbance to this area may occur before the end of
the 5-10 year project life.
Alternatives 7 and 9 would require filling sandbags using the swash zone as the source of
sands. Removal of sand would be gradual and should result in only minor and temporary
changes in beach profile. Benthic organisms in the swash zone borrow area would
probably be lost, but those in adjacent areas should not be substantially affected. Because
the area of this sand removal will be limited and the work will occur only once within a
relatively short period of time, recovery of the beach profile and populations of swash
zone organisms should be very rapid. For these reasons, the overall impacts of extracting
sand from the swash zone are considered minor.
Dune Grass Community
Description. This is the dominant community in the project area and is located between
the beach/sand community and the salt marsh community. Most of the dune systems in
the project area have been artificially created and maintained to protect NC 12 from the
encroaching ocean.
Natural dunes build as windblown and wave-deposited sand is deposited around
vegetation such as sea oats (Unioia paniculata), American beach grass (Ammophila
breviligulata), silver panic grass (Panicum amarum), sandspur (Cenchrus tribuloides),
beach pea (Lathyrus japonicus) and saltmeadow cordgrass (Spartina patens). The root
systems of these species and others, including broomstraw (Andropogon sp.), seaside
goldenrod (Solidago sempervirens) and beach elder (Iva imbricata), stabilize the dune
and prevent further wind erosion.
The dune grass community exhibits relatively low animal diversity compared to other
communities associated with barrier islands. Red-winged blackbirds (Agelaius
phoeniceus) and savannah sparrows (Passerculus sandwichensis) can be found among the
relatively sparse vegetation while laughing gulls (Larus atricilla) and gull-billed terns
(Sterna nilotica) fly the dune lines and dune fields in search of insects.
Another part of the dune grass community is the overwash zone. This landward portion
of the community is located in areas where the dune line has been breached by wave
action, normally as a result of storm tides. Sections of barrier islands that have lost their
protective dunes and that are continually overwashed are susceptible to inlet creation at
the overwash location. Overwash prevention may also cause sound side erosion because
saltmarsh buffers grow at overwash edges.
44
Vegetation in overwash zones is dependent on the recentness of the event that created the
overwash. Areas that are continually overwashed may not exhibit any vegetation, while
areas that were overwashed only once may be in the process of succeeding back to more
of a dune type community.
Dunes would be affected to some degree by every alternative under consideration as they
are the primary line of defense for minimizing frequency and severity of overwash and
flooding from the ocean. Under the No-Build Alternative (Alternative 1), existing
maintenance activities would continue and new dunes would be recreated after any storm
events that destroy the existing dunes. These dunes would be planted with dune grasses,
but it is unlikely that they would stabilize and provide significant habitat value before
they are lost to another storm event.
Impacts of Alternatives. The Beach Nourishment Alternative (Alternative 2) would have
minimal impact to the existing dune grass habitat of the area as most of the fill required
would be placed seaward of the mean high water line (see Plate P-2). Approximately
26.4 acres (10.7 hectares) of new dune plantings would be provided under this
alternative. In addition, the newly created dune and berm would offer substantial
protection to the existing dune field behind it and allow it to stabilize and increase in
habitat value. Under this alternative, the highway would remain on the existing
alignment; therefore, no dune grass habitat would be disturbed from highway relocation.
Alternative 5 (Road Relocation) would impact approximately 8.6 acres (3.5 hectares) of
dune grass habitat to accommodate the new road. After road relocation, the old road
would be removed, and the area would be regraded and planted with native grasses.
Approximately 6.5 acres (2.63 hectares) of dune grass habitat would eventually be
recovered in this manner, leaving a net loss of 2.1 acres (0.85 hectares) of dune grass
habitat resulting from this alternative.
Alternatives 6, 7, 8, and 9 would impact a similar amount of dune grass habitat for road
relocation (8.6 acres (3.48 hectares)), but for each alternative the existing roadbed would
be removed and buried under a new protective dune. In the area of the old roadbed (6.5
acres (2.63 hectares)), this new dune, which would have a footprint of 32.1 acres (13
hectares) for Alternatives 6, 7, and 8 and 27.4 acres (11.09 hectares) for Alternative 9,
would also be built largely on top of dune grass habitat. This would result in a net impact
to 25.6 acres (10.36 hectares) of dune grass habitat for Alternatives 6, 7, and 8 and 20.9
acres (8.46 hectares) for Alternative 9. However, this new area of dunes would be
planted in native beach grasses to help stabilize them and offset these habitat losses.
Wetlands
Description. This community is found on the sound side of the island between the dune
grass community and Pamlico Sound. It is characterized by tidal flooding and dominated
by black needlerush (Juncus romerianus). Grading upwards toward the dune grass
community the vegetation transitions into a shrubby component dominated by yaupon
45
(Ilex vomitoria), and wax myrtle (Myrica cerifera) with occasional Spanish bayonet
(Yucca filamentosa), prickly pear cactus (Opuntia spp.) and silverling (Baccharis
halimifolia) present.
Birds common to this community include the great blue heron (Ardea herodias), black
crowned night heron (Nycticorax nycticorax), American egret (Casmerodias albus), boat-
tailed grackle (Cassidix mexicanus), and red-winged blackbird. Other animals common
to the community include raccoon (Procyon lotor), marsh periwinkle (Littorina
irrotoria), blue crab (Callinectes sapidus) and a wide variety of microorganisms.
Impacts of Alternatives. Alternative 1 (No-Build) would not have any direct impact on
wetlands. However, as the highway is repeatedly overwashed during future storm events,
sand would almost certainly be carried across the highway and deposited into wetland
areas. This is an entirely natural process. New wetland areas would soon become
established on, or around, such newly deposited overwash sands. Whether this process
will lead to a net increase or decrease of wetlands in the project area is unknown.
Alternative 2, Beach Nourishment Alternative, would be built seaward of the existing
highway and would not impact any wetland areas. It would stop the natural process of
overwash sands entering wetland areas.
Every road relocation alternative (Alternatives 5-9) calls for moving the highway away
from the ocean and closer to Pamlico Sound on the alignment shown on Plate P-3. Since
each road relocation alternative would use the same alignment, each would have the same
footprint except for alternative 5, which uses different roadbed elevations. Alternative 5
would not impact wetlands at a 7-foot (2.1 meters) elevation. At the 10-foot (3.0 meters)
elevation, approximately 0.02 acre (0.008 hectare) of wetlands would be impacted. At
the 14-foot (4.3 meters) elevation, about 0.12 acre (0.049 hectare) of wetlands would be
impacted. No wetland impacts are associated with Alternatives 6, 7, 8, and 9, which
include relocation of the roadway at a grade elevation of about 7 feet (2.1 meters) above
msl.
The alignment for the roadway relocation alternatives has been developed specifically to
avoid impacts to the wetland communities in the project area.
Surf Zone and Near Shore Fishes
Description. Commercial and recreational fishing are major industries along the Outer
Banks. The beaches of the study area are heavily used by surf fishermen. These
fishermen constitute one of the major user groups of study area lands and provide a
substantial influx of dollars into the local economy.
There are no designated Primary Nursery Areas in the study area. Marine waters in the
vicinity of the project area and offshore borrow site provide habitat for a variety of ocean
fish and are important commercial and recreational fishing grounds. Kingfish
(Menticirrhus saxatilis), spot (Leiostomus xanthurus), bluefish (Pomatomus saltatrix),
46
weakfish (Cynoscion regalis), spotted seatrout (Cynoscion nebulosus), flounder
(Paralichthys dentatus), red drum (Sciaenops ocellatus), and Spanish mackerel
(Scomberomorus maculates) are among the many species actively fished for from boats,
the surf, and local piers. The near shore ocean waters from Cape Lookout, North
Carolina to Cape Charles, Virginia are known wintering grounds for the Atlantic Coast
migratory striped bass population. Offshore marine waters serve as habitat for the
spawning of many estuarine dependent species.
The surf zone fisheries of the project area have not been studied. Surf zone fisheries are
typically fairly diverse, with 52 species having been identified from North Carolina to
date (Ross 1996, Ross and Lancaster 1996). The importance of surf zone habitat to
maintain health stocks of certain species has only recently come under investigation.
Preliminary studies by Ross and Lancaster (1996) indicate that juveniles of certain
species may have high site fidelity and extended residence time in the surf zone,
indicating that the surf zone may be functioning as a nursery area. Two species in
particular, the Florida pompano (Trachinotus carolinus) and gulf kingfish (Menticirrhus
littoralis), seem to use the surf zone exclusively as a juvenile nursery area.
Ross (1996) identified the following species of fishes collected from the surf zone in
North Carolina. Two sampling areas are represented, Masonboro Island in New Hanover
County, and Atlantic Beach in Carteret County. At the time of this report, Masonboro
Island data was preliminary. For convenience, the data from these sites has been
combined below.
bluntnose stingray (Dasyatis say) gray snapper (Lutjanus griseus)
blueback herring (Alosa aestivalis) pinfish (Lagodon rhomboides)
Atlantic menhaden (Brevoortia tyrannus) banded drum (Larimus fasciatus)
threadfin shad (Dorosoma petenense) spot (Leiostomus xanthurus)
striped anchovy (Anchoa hepsetus) southern kingfish (Menticirrhus americanus)
bay anchovy (Anchoa mitchilli) gulf kingfish (Menticirrhus littoralis)
skilletfish (Gobiesox strumosus) northern kingfish (Menticirrhus saxatilis)
Atlantic needlefish (Strongylura marina) unidentified kingfish (Menticirrhus sp.)
silverstripe halfbeak (Hyporhamphus unifasciatus) black drum (Pogonias cromis)
striped killifish (Fundulus majalis) red drum (Sciaenops ocellatus)
rough silverside (Membras martinica) striped mullet (Mugil cephalus)
Atlantic silverside (Menidia menidia) white mullet (Mugil curema)
northern searobin (Prionotus carolinus) great barracuda (Sphyraena barracuda)
bluefish (Pomatomus saltatrix) Spanish mackerel (Scomberomorus maculatus)
sharksucker (Echeneis naucrates) gulf flounder (Paralichthys albigutta)
crevalle jack (Caranx hippos) summer flounder (Paralichthys dentatus)
lookdown (Selene vomer) southern flounder (Paralichthys lethostigma)
Florida pompano (Trachinotus carolinus) broad flounder (Paralichthys squamilentus)
permit (Trachinotus falcatus) windowpane (Scophthalmus aquosus)
unidentified mojarra (Eucinostomus sp.) scrawled filefish (Aluterus scriptus)
schoolmaster (Lutjanus apodus) planehead filefish (Monacanthus hispidus)
red snapper (Lutjanus campechanus) northern puffer (Sphoeroides maculatus)
47
In 1996, Ross and Lancaster reported the final findings of their Masonboro Island study.
Thirty species were encountered, most of which are represented in the listing above;
however, they also encountered the following additional species:
chain pipefish (Syngnathus louisianae) striped burrfish (Chilomycterus schoepfi)
northern pipefish (Syngnathus fuscus) mummichog (Fundulus heteroclitus)
palometa (Trachinotus goodei) leopard searobin (Prionotus scitulus)
Atlantic croaker (Micropogonias undulatus) bighead searobin (Prionotus tribulus)
Additional study of the value of the surf zone to fisheries would enhance the scientific
community’s knowledge about this issue, particularly information regarding trophic
structure and potential direct and indirect impacts of placing sand on the beach. Studies
of the surf zone fishes of the Outer Banks would also be beneficial. However, such
intense studies were not conducted as a part of this study for interim improvements to the
NC 12 corridor.
Recently, evidence has come to light indicating that fish larvae in the ocean waters off the
Outer Banks generally travel westward until they encounter the shoreline then migrate
along the shoreline until they encounter an inlet (Dr. John Miller, North Carolina State
University, personal communication). Inlets are important passageways for the larvae of
many species of commercially or ecologically important species of fish. These larvae,
hatched in the open ocean, migrate inshore and enter into the sounds through inlets. The
sounds, with their abundant marshes, creeks, and sheltered areas, serve as nursery habitat
where the young fish undergo rapid growth before returning to the ocean.
Larval fish diversity in the nearshore ocean off of the Outer Banks is very high. Larvae
of the following species of fish were recorded as using Oregon Inlet by Hettler and
Barker (1993):
Ladyfish (Elops saurus) Mojarra sp. (Eucinostomus sp.)
American eel (Anguilla rostrata) Pigfish (Orthopristis chrysoptera)
Conger eel (Conger oceanicus) Pinfish (Lagodon rhomboides)
Speckled worm eel (Myrophis punctatus) Silver perch (Bairdiella chrysoura)
Atlantic menhaden (Brevoortia tyrannus) Spotted seatrout (Cynoscion nebulosus)
Atlantic thread herring (Opisthonema oglinum) Weakfish (Cynoscion regalis)
Striped anchovy (Anchoa hepsetus) Spot (Leiostomus xanthurus)
Bay anchovy (Anchoa mitchilli) Kingfish sp. (Menticirrhus sp.)
Anchovy sp. (Anchoa sp.) Atlantic croaker (Micropogonias undulatus)
Inshore lizard fish (Synodus foetens) Red drum (Sciaenops ocellatus)
Lantern fish sp. (Genus undetermined) White mullet (Mugil curema)
Skilletfish (Gobiesox strumosus) Great Barracuda (Sphyraena barracuda)
Cusk-eel sp. (Ophidion sp.) Southern stargazer (Astroscopus y-graceum)
Atlantic silverside (Menidia menidia) Butterfish (Peprilus triacanthus)
Dusky pipefish (Sygnathus floridae) Scorpenid sp. (Genus undetermined)
Northern pipefish (Sygnathus fuscus) Northern searobin (Prionotus carolinus)
Chain pipefish (Sygnathus lousianae) Searobin sp. (Prionotus sp.)
Black sea bass (Centropristis striata) Eyed flounder (Bothus ocellatus)
Bluefish (Pomatomus saltatrix) Gulf Stream flounder (Citharichthys arctifrons)
Gray snapper (Lutjanus griseus) Flounder sp. (Citharichthys sp.)
Tripletail (Lobotes surinamensis) Fringed flounder (Etropus crossotus)
Smallmouth flounder (Etropus microstomus) Spanish mackerel (Scomberomorus maculatus)
Gulf flounder (Paralichthys albigutta) Harvestfish (Peprilus alepidotus)
Feather blenny (Hypsoblennius hentzi) Summer flounder (Paralichthys dentatus)
Darter goby (Gobionellus boleosoma) Windowpane (Scopthalmus aquosus)
Sharptail goby (Gobionellus hastatus) Hogchoker (Trinectes maculatus)
Naked goby (Gobiosoma bosci) Offshore tonguefish (Symphurus civitatus)
Seaboard goby (Gobiosoma ginsburgi) Blackcheck tonguefish (Symphurus plagiusa)
Goby sp. (Gobiosoma sp.) Planehead filefish (Monacanthus hispidus)
Clown goby (Microgobius gulosus) Northern puffer (Sphoeroides maculates)
Pink wormfish (Microdesmus longipinnis)
Impacts of Alternatives. Alternative 1 (No-build) would have no direct impact on surf
zone or near shore fisheries.
Of the alternatives under consideration, the Beach Nourishment Alternative (Alternative
2) would have the greatest affect on surf zone and near shore fisheries. The Beach
Nourishment Alternative could affect fishes during both offshore dredging and placement
of dredged material on the beach.
As discussed previously, the fishery of the surf zone is not well understood nor have the
impacts of sand placement on the surf zone fishery been thoroughly investigated. Ross
(1996) investigated the literature on this subject and determined “there has been almost
no assessment of the effects of beach nourishment on surf zone fishes of this area” [South
Atlantic Bight].
Fishes in the surf zone are believed to be fairly well adapted to their high-energy
environment and, as such, can tolerate environmental extremes brought about by
hurricanes or other violent storms. Most of their prey species, which share this habitat,
are similarly tolerant. However, in a natural environment, extreme conditions are
infrequent, and recovery times are usually adequate for restoration of prior population
levels. Deposition of sands would occur every few years under the Beach Nourishment
Alternative allowing some recovery between nourishment events. Being comprised of
mobile animals, fish populations will probably not be directly affected by habitat
disruption, but these repeated disruptions could lead to declines in their prey base,
diminishing the habitat’s carrying capacity for fishes. Additional studies that address the
trophic structure of the surf zone fish community and the recovery potential of benthic
infauna under repeated disturbances are needed to fully understand the impacts of such
activities.
In some areas, turbidity from dredge disposal operations has been noted as a source of
impacts to fishes. Based on other dredging and beach disposal operations along the Outer
Banks, this is not believed to be a significant concern in the study area. Sands from the
proposed borrow area are coarse and little turbidity is to be expected. Any turbidity
increases would be slight and limited to the near shore area, a result of the dredged slurry
49
entering ocean waters and the winnowing of fines by wave and current action. Turbid
waters, if any, will hug the shore and be transported with waves either north or south,
depending on wind conditions. Such turbidity increases would be temporary in nature
and levels would return to background conditions once dredging is completed. If
turbidity impacts to fishes do occur, they would be localized. Effects would be expected
to be more significant to larval fish that are temporarily residing in surf zone since they
are less mobile and may be unable to evacuate the area if conditions become degraded.
Impacts of dredging on larval fish and shellfish is not well known; however, it can be
safely assumed that any larval organisms picked up by a dredge will be killed due to their
fragility and the extreme pressure and abrasion that they will encounter while passing
through a dredge pump. Larval fishes are almost certainly taken by dredges, and of the
two dredge types that could pump sand to the beach, hopper dredges are assumed to have
the highest take levels since these dredges repeatedly sweep the bottom with suction
dragheads. Pipeline dredges, in contrast, are essentially stationary and should only take
larval fishes passing through a limited area. However, because of the size of the borrow
area, the amount of area being affected by dredging at any one moment, regardless of
dredge type, is comparatively small and the likelihood of taking a significant number of
the fish larvae present is very remote.
Direct impacts of dredging on adult fishes in the borrow area should be relatively benign
as most will be mobile and should be able to avoid being entrained. However,
disturbance of the bottom community, to which some of these species may be closely
tied, may cause temporary shifts in the areas occupied.
Alternatives 5, 6, and 8, which use fill from upland sources and do not directly impact the
surf zone, should have little to no impact on fisheries. Alternative 5 (road relocation
without any protective dune or other feature) would probably not have any effect on the
swash zone.
Alternatives 7 and 9 call for extracting sand from the swash zone to fill sand bags. The
value of the swash zone as habitat for fishes may be diminished during the extraction
period and some small fishes may be entrained. However, because of the limited
duration and extent of this activity, these impacts are considered minor.
Alternatives 6, 7, 8, and 9 all have dune features that protect the relocated road and,
accordingly, carry the project footprint seaward. While the dune for each alternative lies
above the mean high water line, normal or storm driven erosion could cause damage to
the seaward toe of the dune. If this happens, maintenance activities such as trucking in
fill and shaping and grading it would be required. Most of these activities should occur
outside of the swash zone but depending on the severity of erosion, disturbance to this
area may occur before the end of the 5-10 year project life. Should this area be disturbed
by maintenance, some minor impacts to fisheries may occur.
50
Near Shore Benthos
Description. Sand excavation and material disposal for the shore protection alternative
(Alternative 2) would occur in the near shore ocean in an area described by Day et al.
(1971) as the “turbulent zone.” The turbulent zone includes ocean waters from below
low tide to a depth of about –60 feet (-18.3 meters). The potential borrow area proposed
for project construction and maintenance of the Beach Nourishment Alternative is located
about 2.3 miles (3.7 kilometers) off the beach in North Carolina state waters (within 3
miles (4.8 kilometers) of shore) between the minus 30-foot (-9 meter) and 50-foot (-15
meter) depth contours. Beach nourishment will introduce fill into nearshore waters out to
about the – 20-foot (-6.1 meter) depth. Benthic organisms, phytoplankton and seaweeds
are the major primary producers in this community with species of Ulva, Fucus, and
Cladocera being fairly common where suitable habitat occurs. Surveys have indicated
that there are no hard bottoms within the proposed borrow area.
While no benthic surveys have been performed in the potential borrow area, benthic
surveys of three nearshore ocean sites located off nearby Virginia Beach (north of the
project area) were conducted for the USDOI Minerals Management Service in 1996 and
1997 by Cutter and Diaz (1998). They collected a total of 119 taxa from 13 Smith-
MacIntrye grabs in collected in 1996. Half of the top 14 taxa (occurrence and
abundance) were polychates. The remainder included representatives of amphiods,
decapods, bivalves, nemerteans, tanaids, echniderms, and chordates. They found the
overall community composition to be typical for sandy shallow continental shelf habitats
and similar with species composition for similar depths and sediment types reported by
Day et al. (1971) for North Carolina. Benthic resources in the proposed borrow site are
expected to also be similar to those found during these studies. The most abundant
species (total number > 50) collected by Day (1971) in waters within the turbulent zone
near Cape Lookout are listed below. Polychaetes are well represented, as are pelecypods,
decapods, amphipods, echinoderms, and Cephalochordates.
Archiannelida
Polygordius sp. Decapoda
Polychaeta Dissodactylus mellitae
Palaenous heteroseta Pelecypoda
Pseudeurythoe ambigua Spisula ravenelli
Exogone dispar Gastropoda
Goniadides n.sp Olivella adelae
Magelona papillicornis O. mutica
Ophelia denticulata Echinoidea
Macroclymene zonalis Mellita quinquiesperforata
Amphipoda Cephalochordata
Platyischnopus n.sp Branchiostoma caribbaeum
Maera sp.1
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Impacts of Alternatives. Only the Beach Nourishment Alternative would impact
nearshore ocean waters. Excavation of sand from the offshore borrow site would result
in the total loss of all benthic organisms present in the area being dredged. This loss
should be temporary as recolonization would occur after dredging has been completed.
Moreover, since it is not known what types of sediments will fill in the borrow site,
changes in substrate may result in essentially permanent changes in the benthic
communities present. However, because the amount of area being affected by dredging is
comparatively small within the much greater near shore Atlantic Ocean, the likelihood of
significant long-term impacts on benthic organisms is remote.
2. Rare/Protected Species
The U. S. Fish and Wildlife Service and the National Marine Fisheries Service have
responsibility for federally protected species. As of June 16, 2000, the U.S. Fish and
Wildlife Service lists the following federally protected species for Dare County. Table 6A
lists the federally protected species for Dare County. The most recent list published by the
National Marine Fisheries Service was December 28, 1999. Detailed species descriptions
and impact assessments are provided only for those species that have the potential for
occurring within the project area.
TABLE 6A. FEDERALLY-PROTECTED SPECIES FOR DARE COUNTY
SCIENTIFIC NAME COMMON NAME STATUS
Alligator mississippiensis American alligator T (S/A)
Canus rufus Red wolf EXP
Eubalena glacialis Right whale E
Megaptera novaeangliae Humpback whale E
Balaenoptera physalus Finback whale E
Balaenoptera borealis Sei whale E
Physeter catodon Sperm whale E
Trichechus manatus Manatee E
Charadrius melodus Piping plover T
Haliaeetusleucocephalus bald eagle T (proposed for delisting)
Picoides borealis red-cockaded woodpecker E
Sterna dougallii roseate tern E
Caretta caretta Loggerhead sea turtle T
Chelonia mydas green sea turtle T
Dermochelys coriacea leatherback sea turtle E
Lepidochelys kempii Kemp’s ridley sea turtle E
Eretomochelys imbricata Hawksbill sea turtle E
Acipenser brevirostrum Shortnose sturgeon E
Amaranthus pumilus seabeach amaranth T
“E” denotes Endangered (a species that is in danger of extinction throughout all or a significant portion of its
range).
“T” denotes Threatened (a species that is likely to become an endangered species within the forseeable future
throughout all or a significant portion of its range).
“T (S/A)” denotes a species that is Threatened due to similarity of appearance to another federally protected
species and is not subject to Section 7 consultation.
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“EXP” denotes a taxon that is listed as “experimental” (either essential or non-essential. Experimental, non-
essential endangered species are treated as threatened on public land for consultation purposes and as species
proposed for listing on private land.)
Species: American alligator – Threatened due to similarity of appearance
The American alligator occurs in North Carolina throughout the coastal plain north to the
Albemarle Sound region. It is most common in freshwater environments but frequently
occurs in estuarine situations. None are known from the project area. The species feeds
on a variety of fish, crayfish, and turtles. The alligator is no longer considered
endangered or threatened under the Endangered Species Act but has been retained on the
list under the Similarity of Appearance clause to help control illegal trade in other
severely endangered crocodile species. None of the alternatives under consideration will
affect the American alligator.
Species: Red wolf – Endangered
The red wolf has been reintroduced to North Carolina at the Alligator River National
Wildlife Refuge. It is not known to occur in the project area or on any of the barrier
islands of Dare County. Since the red wolf is known only from the mainland of Dare
County, none of the proposed alternatives is likely to adversely affect the species.
Species: Manatee – Endangered.
The manatee is only an “occasional seasonal visitor to North Carolina waters,” with
populations that are “presumed to be low” (Clark, 1987). Schwartz (1995) gives nine
Dare County records of the manatee: from the Atlantic Ocean, Collington Bay, Roanoke
Island (2), Wanchese, Rodanthe (2), Stumpy Point, and the sound near Hatteras. All of
these records fall between late June and the end of October. There is no information
available which would allow the prediction of its occurrence at any given site at any
given time. Therefore, while it has been reported from Dare County within the project
area before, there is no attainable probability, or reliable way, of predicting its occurrence
there again during any given time period. Studies currently underway by the USFWS
using animals fitted with satellite transmitters will hopefully shed some light on the
nature of these seasonal movements.
While the Florida manatee has been reported from the project area in prior years, there is
no way of predicting its occurrence there again during any given time period. It can only
be assumed that the likelihood of it occurring in the area is very low. The presence of a
dredge to construct Alternative 2 should not significantly affect valuable food resources
for the species nor pose a significant threat to the species. It would be expected that if a
manatee approached an area being dredged, it would avoid the vicinity of the dredge
boat. Due to its rare occurrence in the area and the slow moving nature of the dredges
that would be used in maintaining the project, it has been determined that the
construction and maintenance of any of the alternatives under consideration is not likely
to adversely affect the manatee.
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Species: Right Whale – Endangered.
Current right whale stocks in the North Atlantic are estimated to be a few hundred
individuals. The species summers in the region of the Bay of Fundy and overwinters in
the nearshore waters of south Georgia and northern Florida. North Carolina sightings of
right whales represent migrating individuals. Right whales swim very close to the
shoreline and are often noted only a few hundred meters offshore (Schmidly, 1981). This
species occurs infrequently in the ocean off the coast of North Carolina, usually in
association with spring migrations. Right whales have been documented along the North
Carolina coast, as close as 250 meters from the beach, between December and April (Dr.
Frank J. Schwartz, personal communication). Sightings are most common from mid to
late March. Right whales feed primarily on copepods and euphausiids (Schmidly, 1981).
Calves are produced in late winter and become sexually mature in about 8 years.
Females are believed to calve about every three to four years. There are no documented
threats to the right whale in the project area. Destruction or pollution of right whale
habitat is not known to be a problem in the project area. The only potential threat to the
right whale is from collision with boats navigating in the ocean.
Only Alternative 2, beach nourishment, would affect near shore ocean habitat. Hopper
dredges and other vessel traffic can pose a collision threat to near shore right whales
during operation. Pipeline dredges, being essentially stationary, pose no collision threats.
In order to minimize this threat, any commercial hopper dredge working in the project
area would be required to have trained observers on board during periods of whale
migrations. If whales are spotted, the dredges would reduce speed, and alter course as
necessary until the whales have left the project vicinity. Since habitat conditions and
food supplies will be maintained, and appropriate collision avoidance measures
implemented, it has been determined that none of the alternatives under consideration,
including construction and maintenance of this shoreline protection alternative, are likely
to adversely effect the right whale
Species: Finback whale, humpback whale, sei whale, and sperm whale – Endangered.
These species all occur infrequently in the ocean off the coast of North Carolina. Their
occurrence in the State’s waters is usually associated with spring or fall migrations.
Of the alternatives under consideration, only Alternative 2 would have construction
activities taking lace within the habitat of these species. Collision avoidance measures,
as described under the discussion of the right whale, above, also protect any nearshore
members of these species. Productivity of the nearshore ocean would not be diminished;
therefore, the food supply of these species should be unaffected. Since existing habitat
conditions and food supplies would be maintained, and appropriate collision avoidance
measures implemented, it has been determined that none of the alternative under
consideration, including the construction and maintenance of Alternative 2, are likely to
adversely affect the above listed species of whales.
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Species: Piping plover – Threatened
Characteristics: The piping plover is a small shorebird resembling a sandpiper, weighing
42-56 g, with a length of 15-20 cm. Their plumage is white below and brownish gray
above, with a black band across the forehead and a black ring around the neck. The black
marking may be indistinct during the winter. The legs are yellow, and the bill is yellow
in summer and dark in the winter. Chicks are precocial and covered with a sandy-colored
down. This plover’s call is a clear “peep-lo.” This bird’s movement pattern during
foraging is like that of most plovers, running in short starts and stops.
Distribution and Habitat: The piping plover has a breeding range including the Great
Lakes region and the Atlantic Coast between Newfoundland and Brunswick County,
North Carolina. Populations in the Great Lakes region are listed as Endangered;
populations elsewhere in the range are listed as Threatened. This species winters on the
Atlantic and Gulf of Mexico coasts from North Carolina to Mexico, and the Bahamas and
West Indies. There are no records of piping plover nesting from the project area;
however, the species is known to use the beaches of the Cape Hatteras area on migration
and as wintering habitat. Preferred habitat consists of large sandflats or mudflats for
foraging in close proximity to a sandy beach for roosting and nesting.
Critical habitat for wintering piping plovers has recently been proposed in coastal areas
throughout the Atlantic and Gulf coasts. This proposal includes the beaches at, and near,
Cape Hatteras point to south of the project area. None of the project area to be affected
by the alternatives under consideration has been proposed for critical habitat designation.
Piping plovers nest on sandy or gravelly beaches in sparsely vegetated areas that are
slightly higher in elevation than the surrounding beach. The nest is a shallow scrape in
the sand, often with shell fragments in it, and a clutch usually consists of four eggs. The
eggs hatch in May and the young fledge about a month later. Parents will often try to
distract predators from the nest by feigning a broken wing. Migration to the wintering
grounds occurs in early September.
Piping plovers eat a wide variety of worms, fly larvae, beetles, crustaceans, mollusks, and
other invertebrates (Bent 1928). The foraging behavior consists of quick darting
movement across the sand or mudflat, with sudden stops to probe the sand for food items.
Threats to Species: The greatest threats to the piping plover are habitat loss and
disturbance of nesting areas. Coastal construction and dune, shoreline, and inlet
stabilization have resulted in a loss of suitable nesting habitat. Increasing development of
beach areas for recreational uses has led to direct mortality of nesting birds through
pedestrian and vehicular traffic, and has indirectly lowered productivity through
disturbance of territory establishment, courtship, egg laying, and incubation.
Additionally, the increased presence of humans on the coast has attracted greater
numbers of raccoons and gulls. These animals, in addition to scavenging the trash left by
humans, will prey on piping plover chicks and eggs.
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Distinctive Characteristics: Piping plovers can be distinguished from snowy plovers by
their thicker bills and paler backs, and from semipalmated plovers by their brighter legs
and paler backs.
Biological Conclusion: Only the No-Build alternative (Alternative 1), the Road
Relocation Alternative (Alternative 5), and Road Relocation with Dune Alternative
(Alternative 6) would be unlikely to affect piping plover habitat, provided the elevation
of the roadway is approximately the same as the existing roadway. The other alternatives
involve stabilization methods (sheet piling or sandbags) that may result in erosion of
potential nesting habitat if exposed during the design life of the project. Beach
disturbance from the construction and maintenance of the alternatives will also reduce the
number of food organisms available to foraging plovers throughout the life of the project.
For these reasons, it has been determined that all alternatives except Alternatives 1, 5,
and 6 (without a substantial elevation increase) may adversely affect the piping plover.
Species: Bald eagle – Threatened
The bald eagle ranges throughout eastern North Carolina. While it is known that the
species occasionally uses the project area, there are no known roosting or nesting areas
within the project limits. The species feeds principally on fish and is, therefore,
dependent on water quality that is sufficient to maintain an adequate forage base.
None of the alternatives under consideration should affect nesting habitat for the bald
eagle. Only Alternative 2 (Beach Nourishment Alternative), would use dredging, and
direct take of fishes by dredging would be minimal; therefore, the availability of prey
fishes should not be significantly affected. For these reasons, it has been determined that
constructing and maintaining any of the proposed alternatives is not likely to adversely
affect the bald eagle.
Species: Red-cockaded woodpecker – Endangered
This species is an inhabitant of mature pine stands and, while known from the mainland
portions of Dare County, is not known from the project area or any of the county’s barrier
islands.
The red-cockaded woodpecker is a medium-sized woodpecker that occurs in mature open
pine forests of the southeastern United States. Its habitat has been severely depleted
throughout its range by competing land uses such as urban/residential areas, agriculture,
and pulpwood forestry operations. This species is known throughout the coastal plain of
North Carolina and occurs in Dare County. Since there are no pine forests in the study
area, none of the alternatives under consideration is likely to adversely affect the species.
Species: Roseate tern – Endangered
In North Carolina, the roseate tern is most frequently found as a transient between late
March and mid-May in the spring and late-July to October in the fall (Potter, et al., 1980).
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Only one nest has been recorded for the state. This nesting occurred on a dredged
material disposal island near Core Banks, Carteret County, in 1973. Recently, summer
records of this species have been reported, but breeding has not been recorded. It
frequently breeds in mixed colonies in close association with common terns. Pearson, et
al. (1942) record four specimens from the state, all from the Outer Banks. Of these four,
three occurred during August and one, inexplicably, during January. Currently, nesting
by this species in the United States is restricted to isolated locales in New England and
Florida. Like other terns, this species feeds by diving from the air upon small fish
swimming near the surface of the water.
In its New England and Florida nesting areas, this species has been usurped from most of
its traditional nesting sites by human activities and an expanding population of gulls. The
limiting factors that historically, and presently, prohibit more frequent nesting of this
species in the mid-Atlantic region are unknown. Other species in the region have
flourished with the provision of secluded dredged material disposal islands for nesting
sites, however, this species has not similarly responded.
None of the alternatives under consideration would affect any nesting areas for this
species nor would they significantly affect the fishery resources upon which it depends
during migratory periods. For these reasons it has been determined that the alternatives
under consideration are not likely to adversely affect the roseate tern.
Species: Loggerhead sea turtle – Threatened
Characteristics: The loggerhead sea turtle is a large marine reptile, weighing 170-500 kg.
The loggerhead has a large head and blunt, powerful jaws. The carapace and flippers are
reddish-brown and the plastron is yellow. There are five pairs of pleural scutes on the
carapace, with the first touching the nuchal scute. Three scutes on each side connect the
carapace and the plastron.
Distribution and Habitat: The loggerhead sea turtle is mainly a tropical and subtropical
species, but can be found as far north as Newfoundland and as far south as Argentina.
Major nesting areas are located in the southeastern United States, eastern Australia, and
the Sultanate of Oman. Most nesting in the United States takes place on the east coast of
Florida between Cape Canaveral and Palm Beach, although the turtles also use suitable
beaches as far north as Ocracoke Inlet, North Carolina. This species apparently migrates
over long distances, as tagged individuals have been recaptured 2400 km from the
original tagging site.
The loggerhead sea turtle is found in a wide variety of habitats, including the open ocean,
bays, lagoons, salt marshes, creeks, ship channels, and large river mouths. Hatchlings are
often seen in association with floating sargassum seaweed. The diet includes sponges,
jellyfish, mollusks, crustaceans, and fish. Loggerheads often forage in coral reefs, rocky
areas, and shipwrecks.
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On the eastern coast of the United States, the nesting season begins around May and lasts
until November. Females crawl onto the beach at night and excavate a chamber in the
sand, using their hind flippers. They lay 64-341 eggs, the average being about 115.
These hatch in about two months, usually emerging at night. The hatchlings crawl
toward the ocean, possibly using illumination off the water and slope of the beach as cues
to find the water. Little is known about where the young go once they enter the ocean,
but evidence suggests that 12-30 years are required to reach sexual maturity. Females
only nest every 2-3 years, but may lay 2-6 clutches during a reproductive year.
Table 6B below shows the number of sea turtle nests and false crawls (FC)
between the south border of Avon and north border of Buxton, North Carolina
between 1990 and 1998.
TABLE 6B. SEA TURTLE NESTS AND FALSE CRAWLS
IN MANAGEMENT ZONES
90 91 92
YEAR NESTS/FC* NESTS/FC* NESTS/FC*
1990 0 2 1
1991 3 3 4
1992 0 0 0
1993 1 0 2
1994 3/1 4/5 4/5
1995 5/2 3/2 1/0
1996 2/1 0/1 1/1
1997 1/0 3/1 1/1
1998 ½ 7/0 5/0
*False crawls were not entered in database prior to 1994.
One of the nests was laid by a leatherback.
Two of the nests were laid by green turtles.
Threats to Species: The primary threat to the loggerhead sea turtle is loss of nesting habitat.
This includes direct loss due to coastal construction and erosion, as well as excessive artificial
light causing hatchling disorientation after emerging from the nest. Other factors that can
adversely affect this species include nest predation, adult mortality from becoming entangled
in fishing nets or shrimp trawls, ingesting plastic trash (which is mistaken for jellyfish), and
marine pollution.
Distinctive Characteristics: The loggerhead is most easily distinguished from all other sea
turtle species by its reddish brown color. This species can also be distinguished from the
green and hawksbill sea turtles because it has five, not four, pairs of pleural scutes.
Biological Conclusion: The No-Build Alternative (Alternative 1) and Road Relocation
Alternative (Alternative 5) are not likely to adversely effect the loggerhead because their
impacts would occur well back from the beach, removed from areas which could potentially
be used for nesting. For any work that is necessary during turtle nesting season (May 1
through November 15), no heavy equipment would be operated or stored on the beach face
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and, to prevent possible disorientation of turtle hatchlings in the project vicinity, no night
work would be conducted.
The Beach Nourishment Alternative (Alternative 2) would require the placement of sand and
the presence of equipment associated with this action on the beach during the nesting season.
This alternative will change the existing beach as upland and near shore profiles will be
changed and a new dune field established. The impact of this on turtle nesting is unknown.
In some areas, the number of turtle nests laid has increased after beach nourishment. Since
the Beach Nourishment Alternative would have to be constructed during the summer months,
nest monitoring and relocation would be necessary to avoid accidentally burying a turtle nest
with nourishment material. Because of the low density of turtle nesting that takes place in the
project area, it is unlikely that any nests will be missed during normal surveying conditions.
However, nests can be missed during poor surveying conditions resulting in accidental take.
The type of dredge that would construct the Beach Nourishment Alternative is unknown.
Hopper dredges have been documented to take sea turtles while ocean certified pipeline
dredges have not. If hopper dredges are used to construct the Beach Nourishment
Alternative, turtle deflecting dragheads would be required, and inflow screening and observers
would be used to assess any impacts. Because of the possibility of missing nests, accidental
breakage of eggs during nest relocation, alteration of beach nesting habitat by changing the
beach profile, and the possibility of entrainment by hopper dredges, it has been determined
that the Beach Nourishment Alternative may effect the loggerhead sea turtle.
Alternative 6 (Road Relocation with a dune) would be constructed with fill material brought
in from upland sources and would be placed above the existing mean high water line. It
would require approximately 7 months to construct; 3 months to relocate the highway and 6
months to construct the dunes, with 2 months of overlap between the two. The highway could
be relocated at any season of the year without affecting the loggerhead sea turtle. The
majority of the dune construction would be scheduled to occur during the winter months
(November 15-March 31) to avoid most of the sea turtle and shorebird nesting seasons;
however, some encroachment into the sea turtle nesting season may occur. Work would be
planned so that any dune building work outside of the winter months would take place at the
northern and southern ends of the project, where existing dunes would provide a natural
barrier between the beach and the work area. With these provisions, it has been determined
that the construction of Alternative 6 is not likely to adversely affect the loggerhead sea turtle.
Should maintenance of the project be required during the nesting season, new consultation
would be required. NCDOT will coordinate with the U.S. Fish and Wildlife Service on a
case-by-case basis for those maintenance activities.
Alternatives 7 and 9 would both use sandbags as an integral project feature. The dune placed
on top of the sandbags under these alternatives may help to improve the area for turtle nesting.
The sandbags would be filled with sands taken from the surf zone or from an upland source.
If sands are taken from the surf zone, there may be temporary changes in beach profile, with
unknown affects on turtle nesting. Regardless of the source of sands, shoreline erosion that
exposes portions of the bags could accelerate erosion of adjacent areas, adversely affecting
any sea turtle nests present. It is not known if all construction work on these alternatives
could be performed outside of the sea turtle nesting season. Due to the quantity of work
59
required and the possibility of weather delays, encroachment into the sea turtle nesting season
is possible. Maintenance to repair storm-damaged portions of the project may also have to
occur during the nesting season. Because of the uncertainties associated with the source of
material to fill the sandbags, the potential erosion impacts of these alternatives, and the
possibility that construction or maintenance work would have to be performed during the sea
turtle nesting season, it has been determined that both of these alternatives may affect the
loggerhead sea turtle.
The impacts of Alternative 8 (subsurface sheet piling with a dune) on nesting sea turtles
should be relatively benign under most conditions. However, if portions of the sheet piling
were exposed under severe storm conditions, erosion of nesting habitat could be accelerated.
Maintenance to repair storm-damaged portions of the project may also have to occur during
the nesting season. It is not known if all construction work on this alternative could be
performed outside of the sea turtle nesting season. Due to the quantity of work required and
the possibility of weather delays, encroachment into the sea turtle nesting season is possible.
Because of the uncertainties associated with the potential erosion impacts of this alternatives
and the possibility that construction or maintenance work would encroach into the sea turtle
nesting season, it has been determined that this alternative may affect the loggerhead sea
turtle.
Species: Green sea turtle – Threatened
Characteristics: The green sea turtle is a large marine reptile, weighing 100-295 kg. The
smooth, keelless carapace is light to dark brown with darker mottling and the plastron is light
yellow. The head is fairly small with a serrated lower jaw, and there is a single claw on each
front flipper. There are four pairs of pleural scutes on the carapace, with none touching the
nuchal scute, and a single pair of elongated scales between the eyes. Hatchlings generally
have a black carapace, white plastron, and white markings on the edge of the carapace and
flippers.
Distribution and Habitat: The green sea turtle can be found in tropical and temperate waters
from Massachusetts to Mexico on the east coast of North America, and British Columbia to
Baja California on the west coast, as well as Puerto Rico and the U.S. Virgin Islands. Most
nesting in the United States takes place on the eastern coast of Florida between Volusia and
Dade Counties, though some nests have been observed in Puerto Rico and the U.S. Virgin
Islands as well. This species shows strong nest-site fidelity, and individuals often migrate
long distances to return to a particular beach. The breeding populations in Florida and the
Pacific coast of Mexico are listed as Endangered; elsewhere this species is listed as
Threatened.
Adult green sea turtles are generally found in shallow water, especially in lagoons and shoals
inside reefs, bays, and inlets where marine grasses and algae are abundant. Hatchlings are
often seen offshore, in association with floating sargassum seaweed. The diet consists mainly
of marine grasses and algae, although mollusks, sponges, crustaceans, and jellyfish may also
be taken.
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On the east coast of the United States, the nesting season begins in about June and lasts until
September. Females crawl onto the beach at night and excavate a chamber in the sand, using
their hind flippers, in which a clutch of 75-200 eggs is deposited. Incubation takes 48-70
days, and the hatchlings usually emerge at night. The hatchlings crawl toward the ocean,
possibly using illumination off the water and slope of the beach as cues to find the water.
Little is known about where the young go once they enter the ocean, but evidence suggests
that 25-50 years are required to reach sexual maturity. Females only nest every 2-4 years, but
may lay seven clutches during a reproductive year, with 9-13 days between clutches.
The project area is monitored daily for signs of turtle nests by the U. S. National Park Service
during the nesting season. Green sea turtles have been documented to nest in the project area.
Threats to Species: The primary threats to the green sea turtle are overexploitation of adults
and eggs for human food, and loss of nesting habitat (including direct beach loss due to
coastal construction and erosion, as well as excessive artificial light causing hatchling
disorientation after emerging from the nest). Other factors that can adversely affect this
species include adult mortality from becoming entangled in fishing nets or shrimp trawls and
marine pollution.
Distinctive Characteristics: The green sea turtle is most easily distinguished from all other sea
turtle species by the pair of elongated scales between the eyes, serrated lower jaw, and single
claw on each front flipper. This species can also be distinguished from the loggerhead sea
turtle because it has four, not five, pairs of pleural scutes.
Biological Conclusion: The impacts of the alternatives on green sea turtles will be identical to
those on the loggerhead sea turtle, identified above.
Species: Hawksbill sea turtle – Endangered
Characteristics: The hawksbill is a small to medium-sized sea turtle, weighing 35-127 kg.
The carapace is brown, with numerous streaks of reddish brown, yellow, and orange, and the
plastron is yellowish with black spots. The scutes on the carapace are large, thick, and
overlap somewhat, except in very young and old individuals. The head is small and narrow,
with smooth edges on the distinctive beak-shaped jaws. There are two claws on each flipper.
There are four pairs of pleural scutes, none touching the nuchal scute, and two pairs of scales
between the eyes. Hatchlings are black or dark brown, with lighter edges on the carapace and
limbs.
Distribution and Habitat: Hawksbill sea turtles are found in tropical and subtropical oceans.
Sightings have been reported on the east coast of the United States as far north as
Massachusetts, although rarely north of Florida. Nesting takes place at latitudes primarily
between 25 North and 25 South, although nests are occasionally seen in southern Florida,
Puerto Rico, and the U.S. Virgin Islands.
Adult hawksbills are found in coastal waters, especially around coral reefs, rocky outcrops,
shoals, mangrove bays, and estuaries. Juveniles are often seen offshore, in floating mats of
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seaweed. This species nests on a wide range of beach types and substrates, using both low-
and high-energy beaches on islands and mainland sites. The nest is typically placed near or
under vegetation of some sort. The diet consists mainly of sponges, along with barnacles,
mollusks, jellyfish, sea urchins, fish, and plants.
Nesting takes place from April to November, varying widely with location. Females crawl
onto the beach at night and lay a clutch of approximately 160 eggs in a nest dug in the sand.
Incubation lasts about 60 days. Females may nest every 2-3 years, and some may lay more
than one clutch in a single year, separated by an interval of 10-18 days. The age at sexual
maturity is not known for this species, but evidence suggests that it may be in excess of 30
years.
Threats to Species: The primary threat to the hawksbill sea turtle is human harvest of adults
and eggs, for food and tortoiseshell (obtained from the carapace scutes). Other factors that
can adversely affect this species include increased coastal development (leading to loss of
nesting habitat and disorientation of hatchlings by light pollution), adult mortality from
becoming entangled in fishing nets or shrimp trawls, ingesting plastic trash (which is mistaken
for jellyfish), and marine pollution.
Distinctive Characteristics: The hawksbill is distinguished from other sea turtle species by its
small size, distinctive color of its carapace scutes, and beak-like jaws. This species can be
distinguished from the loggerhead and Kemp’s ridley sea turtles because it has four, not five,
pairs of pleural scutes, and the nuchal scute does not touch the first pleural scute. The
hawksbill can be distinguished from the green sea turtle because it has two pairs of scales
between the eyes, not one.
Biological Conclusion: The hawksbill is not known to nest in the project area; therefore, no
alternative will affect nesting females. Hopper dredges have never been documented to take a
hawksbill sea turtle in North Carolina; therefore, a take from this project is unlikely.
However, since such a take is possible, it has been determined that implementation of
Alternative 2 may affect the hawksbill sea turtle.
Species: Kemp’s ridley sea turtle – Endangered
Characteristics: The Kemp’s ridley sea turtle is the smallest of the sea turtles in the project
area, weighing 36-50 kg. This turtle is unique in that its broad, heart-shaped carapace is gray,
and there is a secretory pore near the posterior edge of each scute forming the bridge between
the carapace and plastron. The head and flippers are gray, and the beak is somewhat hooked.
There are five pairs of pleural scutes, the first touching the nuchal scute. Hatchlings are black,
changing as they mature to white then yellow below and green then gray above.
Distribution and Habitat: Adult Kemp’s ridley sea turtles are found only in the Gulf of
Mexico, although juveniles have been seen as far north as Massachusetts. Nesting normally
takes place on the Gulf Coast of Mexico, during the daytime, in large groups known as
arribadas. There have been as many as 40,000 females recorded in a single arribada in
Rancho Nuevo, but the population has declined in recent years, and only about 500 females
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nested at Rancho Nuevo in 1988. An attempt made in 1988 to establish a breeding colony on
Padre Island, Texas involved taking 2,000 eggs from the Rancho Nuevo colony and allowing
them to hatch (and hopefully imprint) on the Texas beach. No Kemp’s ridley sea turtles have
returned to nest on Padre Island at this time. Kemp’s ridley nesting has occurred in North
Carolina, but it is so rare and unusual that its significance cannot be determined.
The Kemp’s ridley sea turtle is found in shallow water, frequently in coastal forests of red
mangrove (Rhizophora mangle). Nearly the entire population nests on approximately 24 km
of beach in the state of Tamaulipas, Mexico. Preferred nesting beaches are backed by large
swamps or open water with narrow ocean connections. The diet consists mainly of crabs,
along with shrimp, snails, sea urchins, sea stars, jellyfish, fish, and occasionally plants.
Nesting takes place in April, May, and June. Females crawl onto the beach during the day in
large groups, usually following a period of north wind. The clutch of approximately 110 eggs
is deposited in a nest dug in the sand. Females may nest every year, and some may lay more
than one clutch in a single year, separated by an interval of 10-28 days.
Threats to Species: The primary threat to the Kemp’s ridley sea turtle is the human harvest of
adults and eggs. Other factors that can adversely affect this species include egg predation by
coyotes, adult mortality from becoming entangled in fishing nets or shrimp trawls, predation
of coyotes, vultures, and fish on hatchlings, ingesting plastic trash (which is mistaken for
jellyfish), and marine pollution.
Distinctive Characteristics: The Kemp’s ridley is most easily distinguished from all other sea
turtle species by its small size, gray color, and the secretory pore on the posterior edge of each
scute of the bridge. This species can also be distinguished from the Green and Hawksbill sea
turtles because it has five, not four, pairs of pleural scutes, and the nuchal scute touches the
first pleural scute.
Biological Conclusion: The impacts of the alternatives on Kemp’s ridley sea turtles will be
identical to those on the loggerhead sea turtle, identified above.
Species: Leatherback sea turtle – Endangered
Characteristics: The leatherback sea turtle is the largest of the turtles, weighing 295-680 kg
with a length of 1.2-1.8 m. This turtle is unique in that its carapace is not composed of hard
scutes, but is rubbery with small bones embedded in it. The carapace has seven longitudinal
keels, and is dark brown or black. The plastron has five longitudinal keels. There is not a
well-defined angle between the carapace and plastron, making the animal somewhat barrel-
shaped. The head and flippers are brown or black with whitish spots, and the flippers have no
claws. The beak is somewhat hooked, with a tooth-like cusp on either side of the upper jaw.
Hatchlings are dark brown or black, with white or yellowish carapace keels, and their skin has
small scales that are lost as the animal grows.
Distribution and Habitat: Leatherback sea turtles are found worldwide, primarily in the
tropics, although they can also be found as far north as Newfoundland and the British Isles
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and as far south as Argentina. Nesting areas are located in the United States from Florida
north to South Carolina (sporadically to Outer Banks of North Carolina), as well as in Malaya,
Surinam, French Guiana, Mexico, Costa Rica, the U.S. Virgin Islands, and Puerto Rico.
The leatherback sea turtle is a strong swimmer and mainly pelagic, often seen near the edge of
the continental shelf. Preferred nesting beaches are usually isolated, with close proximity to
deep water, bordered by vegetation, and steep enough so that dry sand is not too far from the
water. The diet consists mainly of jellyfish, along with some sea urchins, crustaceans, squid,
tunicates, fish, and seaweed.
Nesting in North Carolina is extremely rare. Clutch size is approximately 80-100 eggs, of
which a third may be yolkless. Females may nest several times in a single season, but
probably do not nest every year. Incubation takes 55-74 days, and the hatchlings emerge at
night. They immediately head for the ocean, possibly using light cues to find the water.
The only area of Critical Habitat that has been designated for the leatherback sea turtle is at
Sandy Point, St. Croix, U.S. Virgin Islands. This is defined as the area between 1742’12”N
and 6450’00”W, encompassing waters up to and inclusive of the hundred fathom curve
shoreward to the level of the mean high tide and a strip of land 0.3 km wide from mean high
tide inland.
Threats to Species: The primary threat to the leatherback sea turtle is the human harvest of
eggs and loss of nesting habitat due to beach development, beach renourishment, and erosion.
Disorientation of hatchlings due to lights in coastal development, nest and hatchling mortality
from increased vehicular traffic on beaches, hatchling predation, adult mortality from
becoming entangled in fishing nets or shrimp trawls, ingesting plastic trash (which is mistaken
for jellyfish), and marine pollution can also have a significant negative impact on the species.
Distinctive Characteristics: The leatherback sea turtle is easily distinguished from all other sea
turtle species by its large size, lack of hard scutes on the carapace, and barrel-shaped body.
Biological Conclusion: The impacts of the alternatives on leatherbacks will be identical to
those on the loggerhead sea turtle, identified above.
Species: Shortnose sturgeon – Endangered
The shortnose sturgeon ranges along the Atlantic seaboard from the Saint John River in New
Brunswick, Canada, to the Saint Johns River, Florida. It is apparent from historical accounts
that this species may have once been fairly abundant throughout North Carolina’s waters. In
the recent past, this species was believed extirpated from North Carolina (Schwartz, et al.,
1977). However, during the winter of 1986-87, the shortnose sturgeon was taken from the
Brunswick River, a component of the Cape Fear River basin. Since this discovery, the species
has also been found in the Albemarle Sound system and in the Pee Dee River.
The shortnose sturgeon is principally a riverine species and is known to use three distinct
portions of river systems: (1) non-tidal freshwater areas for spawning and occasional
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overwintering; (2) tidal areas in the vicinity of the fresh/saltwater mixing zone, year-round as
juveniles and during the summer months as adults; and (3) high salinity estuarine areas (15
parts per thousand (ppt) salinity or greater) as adults during the winter. There is no breeding
habitat available for the species in the project area; however, adults of the species from an
undocumented population in the Roanoke/Chowan River basin could overwinter in the area.
The shortnose sturgeon is a bottom feeder, consuming various invertebrates and, occasionally,
plant material. Adults are found in shallow-to-deep water (6 to 30 feet (1.8 to 9.1 meters))
and would be expected to occupy deep water areas during the day and the more shallow
adjacent areas during nighttime foraging periods (Dadswell, et al., 1984). Pollution, dam
building, and over-fishing are generally considered to have been the principal causes of the
decline of this species.
Spawning habitat and nursery habitat for juvenile shortnose sturgeon lie well outside of the
project area and should not be affected by this project. Habitat conditions suitable for
overwintering adults could occur within Pamlico Sound in the project area. The shortnose
sturgeon is a bottom feeder, consuming various invertebrates and occasionally plant material.
Adult foraging activities normally occur at night in shallow water areas adjacent to the deep
water areas occupied during the day. As no dredging in the sound would occur under any
alternative under consideration, construction and future maintenance of any alternative would
essentially maintain the status quo.
The only alternative under consideration that would affect aquatic habitat is beach
nourishment (Alternative 2). Hopper dredges have been documented to take Atlantic sturgeon
and, if a hopper dredge were used to construct Alternative 2, any sturgeon within the area
proposed for borrow would be at risk. Ocean-certified pipeline dredges are not known to take
sturgeons. The offshore borrow area is probably used by Altantic sturgeon but, since the
shortnose is primarily riverine, it is not likely that that species uses the area. For this reason, it
has been determined that the project is not likely to adversely effect the shortnose sturgeon.
Species: Seabeach amaranth – Threatened
Characteristics: Seabeach amaranth is an annual legume that grows in clumps containing 5 to
20 branches and are often over one foot (0.3 meters) across. The trailing stems are fleshy and
reddish-pink or reddish in color. Seabeach amaranth has thick, fleshy leaves that are small,
ovate-spatulate, emarginate and rounded. The leaves are usually spinach green in color,
cluster towards the end of a stem, and have winged petioles. Flowers grow in axillary
fascicles and the legume has smooth, indehsicent fruits. Seeds are glossy black. Both fruits
and flowers are relatively inconspicuous and born along the stem.
Distribution and Habitat: Seabeach amaranth is endemic to the Atlantic Coastal Plain beaches.
Habitat for seabeach amaranth is found on barrier island beaches functioning in a relatively
dynamic and natural manner. Seabeach amaranth grows well in overwash flats at the
accreting ends of islands and the lower foredunes and upper strands of noneroding beaches.
Temporary populations often form in blowouts, sound-side beaches, dredge spoil, and beach
replenishment. This species is very intolerant to competition and is not usually found in
association with other species.
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Threats to Species: Threats to seabeach amaranth include beach stabilization projects, all
terrain vehicles (ATV’s), herbivory by insects and animals, beach grooming, and beach
erosion.
Biological Conclusion: Repeated surveys for seabeach amaranth in the project area by NPS
personnel and NCDOT biologists have failed to find the species. Therefore, the project will
have no effect on seabeach amaranth.
3. Essential Fish Habitat
The 1996 Congressional amendments to the Magnuson-Stevens Fishery Conservation and
Management Act (MSFCMA) (PL 94-265) set forth new requirements for the National Marine
Fisheries Service (NMFS), regional fishery management councils (FMC), and other Federal
agencies to identify and protect important marine and anadromous fish habitat. These
amendments established procedures for the identification of Essential Fish Habitat (EFH) and a
requirement for interagency coordination to further the conservation of Federally managed
fisheries. Table 7 lists, by life stages, the fish species that may occur in the study area that are
managed under MSFCMA (species listed by NMFS for ocean waters north of Cape Hatteras
with EFH expected to occur in beach nourishment Area or the offshore borrow area). Table 8
shows such species that are not expected in the study area. Table 9 shows the categories of
EFH and Habitat Areas of Particular Concern (HAPC) for managed species which were
identified in the Fishery Management Plan Amendments of the South Atlantic Fishery
Management Council and which may occur in southeastern states. These fish species and
habitats require special consideration to promote their viability and sustainability.
The Fishery Management Plan Amendments of the South Atlantic Fishery Management
Council identify a number of categories of Essential Fish Habitat (EFH) and Habitat Areas of
Particular Concern (HAPC), which are listed in Table 10. While all of these habitat categories
occur in waters of the southeastern United States, more than one-third of them are absent from the
project vicinity. Those absent include estuarine scrub/shrub mangroves which require a more
tropical environment, Hoyt Hills located in the Blake Plateau area in water 450-600 meters deep,
Big Rock and Ten-Fathom Ledge located off Cape Lookout, the Cape Fear sandy shoals, New
River located about 60 miles (96.6 kilometers) northeast of Cape Fear, and Bogue Sound located
over 75 miles (120.7 kilometers) northeast of Cape Fear. In addition, there are no Council-
designated Artificial Reef Special Management Zones or seagrass beds in the study area. Impacts
on habitat categories potentially present in the project vicinity are discussed below.
Impacts on Aquatic Beds and Wetlands. Aquatic beds (defined as assemblages of submerged
rooted vascular vegetation found in tidal freshwater areas), estuarine emergent wetlands,
palustrine emergent and forested wetlands all may be present in Pamlico Sound and along its
tributaries. These habitats occur in shallow waters and/or along shorelines, so they are not
within habitats being impacted by any of the alternatives under consideration. The road
relocation alternative will not impact wetlands.
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Impacts on Intertidal Flats, Oyster Reefs, and Shell Banks. These habitat types occur in
Pamlico Sound adjacent to the study area, but they do not occur within the immediate project
area. Therefore, none of the alternatives under consideration will affect these habitat types.
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TABLE 7. SPECIES LISTED BY NMFS FOR OCEAN WATERS NORTH OF CAPE
HATTERAS WITH EFH EXPECTED TO OCCUR IN BEACH NOURISHMENT AREA
OR THE OFFSHORE BORROW AREA
Essential Fish Habitat Shore Protection Offshore Borrow Habitat Areas of Mitigative Measures
– Atlantic Ocean North Area Area Particular Concern
Of Cape Hatteras.
Red drum Adults High Salinity Surf Unconsolidated No HAPC Present Avoid Artificial Reefs
Zones Bottom Borrow and disposal Hard Bottom and Inlets.
areas well removed from Use Beach Quality
any inlet. No impacts to Sand
designated Primary
Nursery
Bluefish Juvenile and Adults Pelagic Waters Pelagic Waters No HAPC Identified Avoid Artificial Reefs
And Hard Bottom Use
Beach Quality Sand
Summer flounder Eggs, Larval, Juvenile Pelagic and Demersal Palagic and Demersal No HAPC Present Avoid Artificial Reefs
and Adult Waters Waters And Hard Bottom. Use
Beach Quality Sand
Snapper Grouper Eggs, Larval, Juvenile Pelagic Environment Soft Sediments No HAPC Present in Avoid Artificial Reefs
Complex and Adult borrow and disposal And Hard Bottom and
Gag Grouper areas. Closest near Inlets. Use Beach
Gray Snapper shore hardbottoms or Quality Sand
artificial reefs > 1 mile.
Coastal Migratory Eggs, Larval, Juvenile Barrier Island Ocean- Barrier Island Ocean- No HAPC Present. Use Beach Quality
Pelagics and Adult except Cobia side Waters side Waters About 4 Mlles to Cape Sand.
Dolphin Juveniles and Adults Hatteras Shoals
Cobia Only.
King Mackerel
Spanish Mackerel
Black sea bass Eggs, Larval, Juvenile Pelagic and Demurral Pelagic and Demurral No HAPC Identified Avoid Artificial Reefs
and Adult Waters Waters And Hard Bottom. Use
Beach Quality Sand
Penaeid Shrimp Eggs, Larval, Juvenile Off shore Marine Off shore Marine No HAPC Present Avoid Inlets. Use
Brown Shrimp and Adult Habitats Habitats In borrow and disposal Beach Quality Sand
Pink Shrimp areas. Borrow and
White Shrimp disposal well removed
from any inlet. No
impacts to designated
nursery areas.
Scalloped hammerhead Juvenile and Adult Shallow Coastal Shallow Coastal No HAPC Identified Use Beach Quality
shark Waters Waters Sand
Dusky shark Juvenile and Adult Shallow Coastal and Shallow Coastal and No HAPC Identified Use Beach Quality
Pelagic waters Pelagic waters Sand
Tiger shark Juvenile and Adult Shallow Coastal Shallow Coastal No HAPC Identified Use Beach Quality
Waters Waters Sand
Atlantic sharpnose Juvenile and Adult Shallow Coastal Shallow Coastal No HAPC Identified Use Beach Quality
shark Waters Waters Sand
Sandbar shark Juvenile and Adult Shallow Coastal Shallow Coastal No HAPC Identified Use Beach Quality
Waters Waters Sand
Scup Eggs, Larval, Juvenile Demersal Waters Demersal Waters No HAPC Identified Use Beach Quality
and Adult Sand
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TABLE 8. SPECIES LISTED BY NMFS FOR OCEAN WATERS NORTH OF CAPE
HATTERAS WITH EFH NOT EXPECTED TO OCCUR IN BEACH NOURISHMENT AREA
OR THE OFFSHORE BORROW AREA
Essential Fish Shore Protection Offshore Borrow Habitat Areas of Mitigative
Habitat - Atlantic Area Area Particular Concern Measures
Ocean North Of
Cape Hatteras.
Atlantic bigeye tuna ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Atlantic bluefin tuna ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Skipjack tuna ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Shortfin mako shark JA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Blue shark JA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Sword Fish ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Yellowfin tuna ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Blue marlin ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
White marlin ELJA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Calico scallop ELJA No Listed Essential No Listed Essential No HAPC Identified EFH South of the
Habitats Present Habitats Present Project Area
Silky shark JA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Longfin mako shark JA No Listed Essential No Listed Essential No HAPC Identified EFH Offshore of
Habitats Present Habitats Present the Project Area
Spiny dogfish Eggs, Larvae, No Listed Essential No Listed Essential No HAPC Identified EFH in Federal
Juveniles and Habitats Present Habitats Present Waters Offshore of
Adult the Project Area
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TABLE 9. CATEGORIES OF ESSENTIAL FISH HABITAT AND
HABITAT AREAS OF PARTICULAR CONCERN IN SOUTHEAST STATES1
ESSENTIAL FISH HABITAT GEOGRAPHICALLY DEFINED HABITAT AREAS
OF PARTICULAR CONCERN
Estuarine Areas Area – Wide
Aquatic Beds Council-designated Artificial Reef Special Management
Zones
Estuarine Emergent Wetlands Hermatypic (reef-forming) Coral Habitat & Reefs
Estuarine Scrub / Shrub Mangroves Hard Bottoms
Estuarine Water Column Hoyt Hills
Intertidal Flats Sargassum Habitat
Oyster Reefs & Shell Banks State-designated Areas of Importance of Managed Species
Palustrine Emergent & Forested Wetlands Submerged Aquatic Vegetation
Seagrass
North Carolina
Marine Areas
Big Rock
Artificial / Manmade Reefs Bogue Sound
Coral & Coral Reefs Capes Fear, Lookout, & Hatteras (sandy shoals)
Live / Hard Bottoms New River
Sargassum The Ten Fathom Ledge
Water Column The Point
1
Areas shown are identified in Fishery Management Plan Amendments of the South Atlantic Fishery Management Council and
are included in Essential Fish Habitat: New Marine Fish Habitat Mandate for Federal Agencies. February 1999. (Tables 6 and 7)
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TABLE 10. SUMMARY OF POTENTIAL IMPACTS TO ESSENTIAL FISH HABITAT
AND HABITAT AREAS OF PARTICULAR CONCERN
Present Potential Impacts
ESSENTIAL FISH HABITAT in Dredge Sediment
Project Plant Disposal
Estuarine Areas Area Operation Activities
1 Aquatic Beds yes no no
2 Estuarine Emergent Wetlands yes no no*
3 Estuarine Scrub / Shrub Mangroves no
4 Estuarine Water Column yes insignificant insignificant
5 Intertidal Flats yes no no
6 Oyster Reefs & Shell Banks yes no no
7 Palustrine Emergent & Forested Wetlands yes no no
8 Seagrass yes no no
Marine Areas
9 Artificial / Manmade Reefs yes no no
10 Coral & Coral Reefs yes no no
11 Live / Hard Bottoms yes no no
12 Sargassum yes no no
13 Water Column yes insignificant insignificant
GEOGRAPHICALLY DEFINED HABITAT AREAS OF PARTICULAR CONCERN
Area – Wide
14 Council-designated Artificial Reef Special no
Management Zones
15 Hermatypic (reef-forming) Coral Habitat & Reefs yes no no
16 Hard Bottoms yes no no
17 Hoyt Hills no
18 Sargassum Habitat yes no no
19 State-designated Areas Important for Managed yes no no
Species
20 Submerged Aquatic Vegetation yes no no
North Carolina
21 Big Rock no
22 Bogue Sound no
23 Capes Fear, Lookout, & Hatteras (sandy shoals) yes no no
24 New River no
25 The Ten Fathom Ledge no
26 The Point no
Areas shown are identified in Fishery Management Plan Amendments of the South Atlantic Fishery Management Council and
are included in Essential Fish Habitat: New Marine Fish Habitat Mandate for Federal Agencies, February 1999.( tables 6 and 7)
71
Impacts on Sargassum. Sargassum is a pelagic brown algae which occurs in large floating mats
on the continental shelf, in the Sargasso Sea, and in the Gulf Stream. It is a major source of
productivity in a nutrient-poor part of the ocean. Masses of Sargassum provide extremely
valuable habitat for a diverse assemblage of animal life, including juvenile sea turtles, sea birds,
and over 100 species of fish. Unregulated commercial harvest of Sargassum for fertilizer and
livestock feed has prompted concerns over the potential loss of this important resource. While
smaller clumps of this seaweed may float into the project area, it typically occurs much
further offshore. Of the alternatives under consideration, only beach nourishment with an
offshore borrow site (Alternative 2) would occur in an ocean area that could contain
Sargassum. Since dredging in the near shore ocean is a bottom oriented activity, it should not
adversely impact either the production or distribution of floating mats of Sargassum.
Therefore, none of the alternatives under consideration will adversely affect the fishery
associated with Sargassum mats.
Impacts on Reef-forming Corals. Hermatypic, or reef-forming, corals consist of anemone-like
polyps occurring in colonies united by calcium encrustations. Reef-forming corals are
characterized by the presence of symbiotic, unicellular algae called zooxanthellae, which impart
a greenish or brown color. Since these corals derive a very large percentage of their energy
from these algae, they require strong sunlight and are, therefore, generally found in depths of
less than 150 feet (45.7 meters). They require warm water temperatures (68o to 82o F) and
generally occur between 30oN and 30oS latitudes. Off the east coast of the United States, this
northern limit roughly coincides with northern Florida. Although they occur off the North
Carolina coast, they are not known from the immediate project vicinity, and they are not likely
to be affected by any of the alternatives under consideration.
Impacts on Artificial Reefs. The State of North Carolina Artificial Reef Program (NCARP)
manages reefs that are located in the ocean waters and sounds of Dare County. There are no
artificial reefs located in the vicinity of the project; therefore, none of the alternatives under
consideration will affect any NCARP reefs.
Impacts on Hardbottoms. Numerous hardbottoms have been documented in the nearshore
ocean off Dare County. However, ocean-bottom surveys of the borrow area that would be
used for the Beach Nourishment Alternative have not indicated any hardbottom in the area
being proposed for borrow. None of the other alternatives would affect ocean habitats.
Therefore, none of the potential alternatives will adversely affect hardbottoms.
Impacts on State-designated Areas Important for Managed Species. Primary Nursery Areas
(PNAs) are designated by the North Carolina Marine Fisheries Commission and are defined by
the State of North Carolina as tidal saltwaters which provide essential habitat for the early
development of commercially important fish and shellfish (15 NC Administrative Code 3B
.1405). There are no designated PNAs located within the study area; therefore, none of the
alternatives under consideration will impact PNAs.
Impacts on the Point off Cape Hatteras near the 200-meter contour. The sandy shoals extending
southeasterly from Cape Hatteras are an area well known to mariners as Diamond Shoals. Very
dangerous to navigation, this area provides important fishery habitat. Its location is south and
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east of the proposed borrow area and outside the area of potential affect from any of the
proposed alternatives.
Impacts on the Marine and Estuarine Water Column. The potential water quality impacts of all
alternatives are addressed below under “Water Quality.” Dredging operations conducted
during construction and maintenance of beach nourishment may create impacts in the marine
water column in the immediate vicinity of the activity. These impacts may include minor and
short-term suspended sediment plumes and related turbidity, as well as the release of soluble
trace constituents from the sediment. During dredging, turbidity increases outside the dredging
area should be less than 25 NTUs and are, therefore, considered insignificant. In the case of
overflowing hopper dredges to obtain economic loading, sediment that is more than 90% sand is
not likely to produce significant turbidity or other water quality impacts. Overall water quality
impacts of the proposed action are expected to be short-term and minor. Living marine and
estuarine resources dependent upon good water quality are not expected to experience
significant adverse impacts due to water quality changes.
Impacts of Larval Entrainment. Life forms that lack the ability to escape the suction field of
an operating dredge or sand pump are subject to entrainment in the flow of water and
sediment passing through its pumping equipment, and mortality is the likely result. However,
only an extremely small percentage (a fraction of 1%) of the marine larvae in the near shore
ocean are realistically subject to entrainment based upon the amount of water that a dredge
can pump. Overall, the pumping or dredging conducted as part of the alternatives is not
expected to create significant impacts on these life forms at local or regional population
levels.
Impact Summary for Essential Fish Habitat. None of the alternatives under consideration are
expected to cause any substantial adverse impacts to Essential Fish Habitat or EFH species.
4. Water Quality
Description. The project area lies between two major water resources, The Atlantic Ocean
and Pamlico Sound. The Best Usage Classification for both is Class A salt waters (SA). The
DENR Index Number is 30-22. Class SA refers to salt waters. SA waters are suitable for
commercial shellfishing and all other tidal salt-water uses including swimming, primary and
secondary recreation, and fish propagation. All Class SA waters also carry a supplemental
classification of High Quality Waters (HQW). HQW is a classification intended for waters
rated as excellent based on biological and physical/chemical characteristics. NCDOT will
strictly adhere to “Design Standards in Sensitive Watersheds” (15A NCAC 04B.0024)
throughout the design and construction of the selected alternative.
Impacts of Alternatives. Only the Beach Nourishment Alternative (Alternative 2) and the
sandbag alternatives (Alternatives 7 & 9) that may extract fill from the surf zone are likely to
affect water quality. Since the material to be moved under either alternative is predominately
sand, no significant increases in turbidity are expected to occur outside of the immediate
discharge area (turbidity increases of 25 NTU’s or less are not considered significant). During
work, increases in near shore turbidity in the immediate area of the work will result from
slurry entering ocean waters and the winnowing of fine-grained sands by wave and current
73
action. Turbid waters (increased turbidity relative to background levels but not necessarily
above 25 NTU’s) will hug the shore and be transported with waves either north or south,
depending on wind conditions. These turbidity increases will be temporary in nature and
levels will return to background conditions once work is completed.
Impacts to water resources from highway runoff will be minimal. In fact, it is anticipated that
the water quality will not change as a result of highway runoff from the proposed project since
the paved surface of the roadway will remain the same as currently exists. No increase in
pavement width is proposed in conjunction with this project.
5. Noise and Air Impacts
Dare County is in compliance with the National Ambient Air Quality Standards. This project
is not anticipated to create any adverse effect on the air quality of the region of this attainment
area.
The project will not increase traffic volumes. Therefore, its impact on noise levels will be
insignificant. Noise levels could increase during construction, but will be temporary.
6. Recreation and Scenery
The project area is a part of Cape Hatteras National Seashore, an area renowned nationwide
for its unspoiled beaches and scenic beauty. In the area of the project, designated public
access to the beaches is limited. A detailed description of the recreational opportunities in
the Seashore is provided in “Section 4(f) Resources” in this document. The scenic qualities
have been degraded by prior erosion of the dunes and roadway.
Under the No-Build Alternative (Alternative 1), aesthetic conditions would remain
unchanged and recreation activities would be impacted following major storm events that
sever access provided. Access within the park would be limited until access could be
reestablished.
The Beach Nourishment Alternative (Alternative 2) would provide a larger beach, berm and
dune for recreational use, but this benefit would go largely unused unless additional parking
and beach access was provided. Access to sound side recreational activities would remain
the same. Travelers on the highway would not have a view of the ocean due to dune
construction.
The Road Relocation Alternative (Alternative 5) would have no significant affect on
recreational activities on the ocean side of the relocated roadway; however, the enjoyment of
sound side recreational activities may be somewhat diminished because the road will be
closer to the sound. Impacts to scenery in the project area would be minimal. Only limited
inconvenience to the traveling public would result during construction of the relocated
roadway.
Like Alternative 5, Alternative 6 (Road relocation with a dune) would result in some
temporary inconvenience to travelers during construction of the relocated road. To this would
be added the additional impact of many dump trucks using the road to haul sand to construct
74
the dune. The new dune would block the view of the ocean and the dune would be located
immediately adjacent to the new roadway. Recreational use of the beach and sound area
would be the same as Alternative 5.
Under Alternatives 7 and 8, (Road relocation with subsurface sandbags and Road relocation
with buried sheet pile, respectively), the aesthetic impacts would be very similar to
Alternative 6 because both plans call for construction of a dune over protective features.
However, if erosion exposes parts of these protective features after construction, accelerated
erosion and beach narrowing would result, degrading the appearance of the area.
Maintenance of these features by the rapid addition of sand to the protective dune should
help to limit these potential effects.
Alternative 9 (road relocation with sand-covered surface sandbags) would be similar to
Alternative 6 with respect to the possible impacts on recreational use of the beach and sound.
Some degradation of the scenery may occur if the sandbags are exposed by foot traffic or
wind or wave generated erosion. Exposed areas of sandbags would quickly be recovered as a
part of the maintenance of the project. As with Alternatives 7 and 8, when ocean erosion
reaches the sandbags, accelerated erosion and beach narrowing would result in degradation
of the aesthetics and recreational utility of the area. Continued maintenance would offset and
limit these impacts.
7. Community and Social Impacts
No minority or low income communities are known to occur in the project area. As no
adverse impacts to either type of community are anticipated as a result of any of the
alternatives under consideration, all are in compliance with Executive Order 12898 (Federal
Actions to Address Environmental Justice in Minority Populations and Low Income
Communities and Low Income Populations).
The existing travel corridor provides many benefits to the residents of the area, allowing
goods and services to flow along the Outer Banks. Under the “No Build” alternative, loss of
this travel route could occur for extended periods of time following a major storm. This
would place severe hardships on the residents of the area and cause significant delays in the
recovery of the area, with the length of recovery delay dependent on the amount of damage
to the roadway. All of the other alternatives meet the project purpose and need and would
protect the highway for the interim period.
8. Jurisdictional Topics
Any activity within the splash zone will require authorization from the U. S. Army Corps of
Engineers. Additionally, the project lies within an Ocean Hazard Area of Environmental
Concern (AEC) and is under the jurisdiction of the North Carolina Division of Coastal
Management (DCM). Activities within the Ocean Hazard AEC will require authorization
from the DCM under the Coastal Area Management Act (CAMA). This project also lies
within Cape Hatteras National Seashore. Therefore, a Special Use Permit will be required
from the U. S. Department of the Interior.
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Lands of Cape Hatteras National Seashore in the project area are considered “Otherwise
Protected Areas” under the Coastal Barrier Resources Act of 1982, as amended, and
therefore are not included in the Coastal Barrier Resources System. Upland borrow sources
that could be used to construct project features may partially occur within CBRA units. Such
sites would be used only if such use is determined to be consistent by the U.S. Fish and
Wildlife Service, the agency that administers the Act.
TABLE 11. SUMMARY OF PERMITS REQUIRED FOR ALTERNATIVES UNDER
CONSIDERATION
PERMIT AGENCY ALTERNATIVES COMMENTS
Special Use National All
Permit Park Service
Section 404 U.S. Army Beach Nourishment Roadway relocation with
Corps of (Alt. 2); Relocated grade of roadway at EL. 7.0
Engineers Road Elevated above would avoid wetlands and
EL. 7.0 (Alt. 5) would not require a 404
permit.
Coastal Area N.C. All Variance would be required
Management Division of for sheetpile alternative (8)
Act Permit Coastal and sand bags alternatives (7
Management & 9)
Section 401 N.C. Beach Nourishment Sandbags may require a 401
Water Quality Division of (Alt. 2); Sandbag certificate because they will
Certificate Water Alternatives (Alts. 7 & be filled from the surf zone.
Quality 9)
9. Cumulative Effects
The project area is subjected to repeated maintenance disturbance following major storm
events in order to clear the roadway and reestablish traffic flow. Such roadway repairs
consist of rebuilding dunes, clearing sand off of the roadway, and rebuilding the road bed, if
necessary. Such activities occur not only in the project area but also in other “hot spot” areas
along the Outer Banks and in the southeastern part of the state (Caswell Beach and North
Topsail Island) where local highways are threatened. These intervening maintenance efforts
keep the natural resources of the barrier island ecosystems from reestablishing a natural
equilibrium with the dynamic coastal forces of the area. The NCDOT desires to minimize
the impacts of maintaining these highways throughout the state. The NC 12 transportation
corridor along the Outer Banks is an area of continuing concern and the NCDOT is working
with other state and Federal agencies and knowledgeable individuals to develop a long-range
transportation plan for the area.
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The No Build alternative (1) would do nothing to minimize the impacts of these repeated
maintenance events on the public or the dune/grassland environment. However, each of the
other alternatives would minimize inconvenience to the public and reduce, to some extent,
the amount of disturbance that would occur to dune/grassland environment. The cumulative
impacts of beach nourishment (Alternative 2) are different from all of the other alternatives.
Throughout North Carolina, maintenance dredging of navigation channels and beach
nourishment projects place sand along the state’s shoreline. The placement of such material
within the 320 miles (515 kilometers) of beachfront along the North Carolina coastline is
summarized below by mileage and maintenance schedule. The summary differentiates
between beach disposal and nourishment. This breakdown is necessary to delineate between
material placed in the swash zone versus on the upper beach and dune system. The
computations are made based on actual mileage used during any given disposal event. For
instance, an approved 5-miles (8 kilometers) of beachfront may be designated for disposal;
however, during a given event only 0.4 to 1 mile (0.6 to 1.6 kilometers) of beachfront may be
impacted. Calculations were made based on a 15-year period (1984-1999) and percentage of
North Carolina Shoreline (320 miles (515 kilometers)) impacted.
DISPOSAL ACTIVITIES:
Average/year – 7.3 miles (11.7 kilometers) or 2.3% of total North Carolina
Shoreline (320 miles (515 kilometers))
Minimum for any year – 4.5 miles (7.2 kilometers) or 1% of total North Carolina
Shoreline
Maximum for any given year is 17.8 miles (28.6 kilometers) or 5.6% of total North
Carolina Shoreline
EXISTING BEACH RENOURISHMENT
Average of 2.9 miles (4.7 kilometers) or 1% of North Carolina Shoreline
Minimum of 0 miles (possible that no beach nourishment in any given year)
Maximum of 9.8 miles (15.8 kilometers) (all occur at same time) which is 3% of
North Carolina Shoreline
PROPOSED BEACH NOURISHMENT PROJECTS (Brunswick and Dare Counties)
Average of 7.8 miles (12.6 kilometers) or 2.4% of North Carolina Shoreline
Minimum would be 0 miles (possible none occurred)
Maximum of 37.3 miles (60 kilometers) which is 11.7% of North Carolina
Shoreline
CUMULATIVE (Averaging both disposal and renourishment projects existing and
future.)
Average impact from existing disposal and renourishment (7.3 miles (11.7
kilometers) + 2.9 miles (4.7 kilometers) = 10.2 miles(16.4 kilometers), 3.2 % of
North Carolina Shoreline.
Maximum impact (worst case) from existing beach disposal and renourishment
activities (17.8 miles (28.6 kilometers) + 9.8 miles (15.8 kilometers)) = 27.6 miles
(44.4 kilometers), 8.6% of North Carolina Shoreline.
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Average impact from existing disposal, renourishment projects and proposed
projects (7.2 miles (11.6 kilometers) + 2.9 miles (4.7 kilometers) + 7.8 miles (12.6
kilometers) = 17.9 miles (28.8 kilometers), 5.6% of North Carolina Shoreline.
Maximum impact (worst case) from existing disposal, renourishment, and
proposed projects (17.8 miles (28.6 kilometers) + 9.8 miles (15.8 kilometers) +
37.3 miles (60 kilometers)) = 64.9 miles (104.4 kilometers), 20.3% of North
Carolina Shoreline.
None of the alternatives under consideration would substantially impact the swash zone
except the Beach Nourishment Alternative (Alternative 2). That alternative would add an
additional 2.1 miles (3.4 kilometers) to receive material about every three years. Adding this
to the calculations above would yield: 1) a maximum beach nourishment figure of 11.9 miles
(19.2 kilometers) or (9.8 miles (15.8 kilometers) + 2.1 miles (3.4 kilometers)) , which equals
roughly 3.7% of the North Carolina shoreline; 2) a maximum future beach nourishment
impact of 39.4 miles (63.4 kilometers) or (37.3 miles (60 kilometers) + 2.1 (3.4 kilometers))
which equals 12.3% of the North Carolina shoreline; and 3) a worst case cumulative impact
for beach nourishment and beach disposal of 67.0 miles (107.8 kilometers) or (64.9 miles
(104.4 kilometers) + 2.1 miles (3.4 kilometers)), which equals 20.9% of the North Carolina
shoreline.
Regardless of the alternative selected, once it is in place the frequency and duration of traffic
interruptions and the maintenance disturbance of dune/grassland habitats in the project area
should be temporarily reduced. However, such disruptions will still occur in other locations
along the Outer Banks and in the southeastern part of the state. Given the length of the
state’s coastline, the temporary repair and protection of the highway at any one of these small
sites is relatively insignificant in scope.
10. Comparative Impacts of Alternatives
The comparative impacts of each alternative under consideration are graphically displayed in
Tables 12A, 12B, and 12 C.
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ADD TABLES 12A – 12C HERE.
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80
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D. Mitigation
No mitigation is being proposed for any alternative under consideration.
V. DRAFT SECTION 4(F) EVALUATION
1. Introduction
Section 4(f) of the Department of Transportation Act of 1966, as amended, (49 U.S.C.
303) states that the US Department of Transportation may not approve the use of land
from a significant publicly owned park, recreation area, or wildlife and waterfowl refuge,
or any significant historic site unless a determination is made that:
There is no feasible and prudent alternative to the use of land from the property;
and
The action includes all possible planning to minimize harm to the property
resulting from such use.
The alternatives under consideration will use land from the Cape Hatteras National
Seashore; thus, the requirements of Section 4(f) are applicable. The alternatives under
consideration will maintain, however, the level of access to the resources now provided
by existing NC 12 within the Seashore.
This chapter documents the location and characteristics of the Section 4(f) property that
will be used by the preferred alternative, describes the impacts to the property, discusses
why no prudent and feasible avoidance alternatives were identified, addresses measures
to minimize harm, and describes coordination with officials having jurisdiction over the
affected Section 4(f) property.
2. Description of Section 4(f) Resource
The Cape Hatteras National Seashore in Dare and Hyde Counties stretches north to south
across three islands: Bodie, Hatteras, and Ocracoke (see Figure 1.) These barrier islands
have a wealth of sand dunes, marshes, and woodland. The Cape Hatteras National
Seashore was established in 1953 and has contributed to the area's increase in tourism. It
was the first in a series of national seashores established to preserve significant segments
of unspoiled barrier islands along the Atlantic and Gulf Coasts. The Cape Hatteras
National Seashore contains 30,319 acres (12,270 hectares) of land and 70 miles (112.7
kilometers) of open and virtually unspoiled beach. The Seashore is owned by the federal
government and administered by the National Park Service. Where the boundaries of the
Seashore overlap with those of the Pea Island National Wildlife Refuge, the National
Park Service takes responsibility for visitors and visitor facilities and the US Fish and
Wildlife Service is responsible for wildlife management.
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Eight communities exist within the Seashore's authorized boundaries (seven on Hatteras
Island) but are not park lands. NC 12, a hard-surfaced, two-lane road serves the
communities and the Seashore. It is approximately 50 miles (80.5 kilometers) in length
within the Seashore. NC 12 is the only road serving motor vehicle travel through the
Seashore and is designated on the Federal-Aid Highway System as an intermodal
connector. NC 12 was built and is maintained by the State of North Carolina under an
agreement with the National Park Service. Access from Bodie Island to Hatteras Island
is provided by the Bonner Bridge. Access to Ocracoke Island is via the Hatteras Inlet
ferry between Hatteras Island and Ocracoke Island and two NCDOT ferry routes
operating between Ocracoke Island and the mainland.
Seashore facilities on Bodie Island include:
Whalebone Junction Information Center
Coquina Beach Day Use Facility
Bodie Island Visitor Center and Nature Trail
Bodie Island Lighthouse
Oregon Inlet Campground
Oregon Inlet Marina and Fishing Center
Seashore facilities on Hatteras Island are:
Pea Island National Wildlife Refuge Nature Trail
Rodanthe fishing pier
Chicamacomico US Life Saving Service Station
Salvo Campground
Little Kinnakeet US Life Saving Service Station
Avon fishing pier
Hatteras Island Visitor Center and nature trail
Cape Hatteras Lighthouse
Cape Point Campground and Day Use Facilities
Frisco Campground
Frisco area fishing pier
Seashore facilities on Ocracoke Island are:
Ocracoke Campground and nature trail
Ocracoke Island Visitor Center
Ocracoke Island Lighthouse
Statistics provided by the National Park Service indicate that visitors to the Cape Hatteras
National Seashore (irrespective of where they are staying) increased from 1,263,837 in
1985 to 2,200,208 in 1990. Visitation in 1999 was 2,772,420. Generally, not only is
Hatteras Island use increasing, but an increasing proportion of residents and visitors to
Dare County are taking day trips to the Hatteras Island portion of the Seashore. NC 12 is
used by most visitors traveling to Hatteras Island and Ocracoke Island facilities.
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Visitors to the Seashore enjoy a wide variety of recreational opportunities that relate to
the unique natural, undeveloped, and protected character of the area. Activities along the
beach area include: sunbathing, beachcombing, swimming, fishing, off-road vehicles,
birding, and kayaking. Soundside activities include: windsurfing, swimming,
outboarding, fishing, birding, off-road vehicles, kayaking, and canoeing.
The length of the proposed project is approximately 12,000 linear feet (3,658 meters),
approximately 3.2 % of the length of the Seashore along Bodie, Hatteras, and Ocracoke
Islands.
3. Applicable Regulations, Policies, and Management Plan for the Cape Hatteras National
Seashore
The General Management Plan and Amended Environmental Assessment for Cape
Hatteras National Seashore (1984) and the Revised Statement for Management (1991)
serve as the National Park Service plans for Cape Hatteras National Seashore. They
provide for the preservation of the cultural resources and the flora, fauna, and natural
physiographic conditions, while allowing appropriate recreational use and public access
to the oceanside and soundside shores. Included in the plan are provisions for controlling
off-road vehicles, providing for accessible oceanside and soundside sites, allowing
natural seashore dynamics to occur, controlling exotic vegetation, preparing natural and
cultural resource studies, and cooperating with state and local governments to achieve
mutual planning objectives.
In 1973, the National Park Service, realizing the problems that the managed dune system
caused to the estuaries, announced a change of policy with respect to management of the
Seashore. The government no longer attempts to stabilize the Outer Banks artificially but
lets natural processes take their course. In its 1991 Revised Statement of Management,
the Park Service affirmed a policy of managing the Cape Hatteras National Seashore in
ways "that support the natural processes of barrier island dynamics..." (National Park
Service, 1991). This Environmental Assessment for interim improvements to NC 12
between Buxton and Avon assumes that this long term policy has not changed despite
recent threats to NC 12 within the Seashore.
No new Seashore facilities are planned in the project area. The Seashore management
plan focuses on restoration and maintenance of existing facilities. It also supports the use
of bicycles along NC 12.
The following regulations, policies, and excerpts from the Cape Hatteras National
Seashore Management Plan are applicable to the project area:
National Park Service Organic Act of 1916: “. . . to conserve the scenery and the
natural and historic objets and the wild life therein and to provide for the
enjoyment of the same in such manner and by such means as will leave them
unimpaired for the enjoyment of future generations.”
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An Act to Amend the Act of October 2, 1968, An Act to Establish a Redwood
National Park in the State of California, and for other Purposes, 1978 (92 Stat.
163): The first section of the Act of August 18, 1970 (84 Stat. 825), is amended
by adding the following: “Congress further reaffirms, declares, and directs that
the promotion and regulation of the various areas of the National Park system, as
defined in section 2 of this Act, shall be consistent with and founded in the
purpose established by the first section of the Act of August 25, 1916 [NPS
Organic Act], to the common benefit of all the people of the United States. The
authorization of activities shall be construed and the protection, management, and
administration of these areas shall be conducted in light of the high public value
and integrity of the National Park System and shall not be exercised in derogation
of the values and purposes for which these various areas have been established,
except as may have been or shall be directed and specifically provided by
Congress.”
Coastal Zone Management Act of 1972 (PL 92-583, 86 Stat. 1280). This act
states a national policy to “preserve, protect, develop, and where possible, to
restore or enhance the resources of the nation’s coastal zones” and to encourage
and assist the states in implementing management programs to achieve wise use
of land and water resources of coastal zones. Federal agencies are required to
comply, as much as possible, with applicable, approved state coastal zone
management programs.
NPS Management Policies (1988): “In natural zones, natural shoreline processes
(erosion, deposition, dune formation, inlet formation and shoreline migration) that
are not influenced by human actions will be allowed to continue without
abatement except where control measures are required by law. The National Park
Service will comply with provisions of State coastal zone management plans
prepared under the Coastal Zone Management Act when such provisions are more
environmentally restrictive than NPS management zoning.” (Chapter 4:20)
Endangered Species Act of 1973.(PL 93-205, 87 Stat. 884). This act requires
federal agencies to ensure that their activities (authorized, funded, or carried-out)
will not jeopardize the existence of any endangered or threatened species of plant
or animal (including fish) or result in the destruction or deterioration of critical
habitat of such species.
Cape Hatteras National Seashore Enabling Legislation: An Act to provide for
the establishment of the Cape Hatteras National Seashore in the State of North
Carolina, and for other purposes, approved August 17, 1937 (50 State. 669):
“Except for certain portions of the area, deemed to be especially adaptable for
recreational uses, particularly swimming, boating, sailing, fishing, and other
recreational activities of similar Nature, which shall be developed for such uses as
needed, the said area shall be permanently reserved as a primitive wilderness and
no development of the project or plan for the convenience of visitors shall be
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undertaken which would be incompatible with the preservation of the unique flora
and fauna or the physiographic conditions now prevailing in this area.”
General Management Plan, Cape Hatteras National Seashore, 1984: “The key
issue in managing the park lands is the perpetuation of shoreline and dune
processes upon which the barrier island ecosystems depend. However, there is a
conflict between this objective and that of maintaining the existing transportation
link to the mainland. The impacts of NC 12 on coastal processes and the long-
term cost of maintaining the highway could be considerably reduced by relocating
the road out of potential overwash areas or elevating it to avoid interference with
overwash and inlet formation. The National Park Service will cooperate with the
state of North Carolina in developing a long-term plan for maintaining the
transportation link. In the interim, temporary remedial actions, including dune
stabilization, may be necessary to maintain access to the national seashore and
villages.”
NPS-77, Natural Resources Management Guideline (1991)
Chapter 2, page 95, Marine Resources Management: The National Park
Service will manage the natural resources of the national park system to
maintain, rehabilitate, and perpetuate their inherent integrity.
Chapter 2, page 98, Disturbance: Many marine organisms and even
ecosystems are well adapted to harsh physical extremes, but are very sensitive
to unnatural perturbations and are slow to recover. Filling areas with dredge
spoil or upland sediment to create more “usable” shoreline is also habitat
disruption. All of these activities can affect substrate types, currents, and
wave patterns, which changes community structure.
Chapter 2, page 100, Adjacent Land Use: Adjacent land use practices can
have a significant effect on coastal resources and processes of park units. . . .
Dredging increases sediment loading and potentially introduces toxins into the
water column. Dredging and filling both modify and destroy habitat such as
coastal wetlands and seagrass beds. Before implementation of dredging or
major construction activities in or outside of the park that could affect coastal
resources in the park, the potential impact to the complex coastal processes
should be carefully identified, and the least damaging approach should be
implemented. The site should then be monitored to assess and document the
impact on the resource.
Chapter 2, pages 110-121, Geological Resources Management: Geological
resources are present in all natural parks. Surficial geologic features are
especially important for their scenic grandeur, their provision of a structural
foundation for biotic system, and as a primary interface with most cycling
ecosystems. They are important for recreation, as well.
Chapter 2, page 118, Coastal Areas/Shorelines: Coastal and shoreline
management entrails more than just the geologic resource itself. The
migration of barrier islands, sand bars, and dunes, the erosion of beaches and
shorelines, and the creation and destruction of lagoons and inlets have impacts
beyond the management of the geologic resource solely for NPS purposes.
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Homes, businesses, the shipping industry, tourism, boating, fishing, and other
coastal activities are all greatly affects by how shorelines are managed. Often
this is out of NPS control. Management must consider federal, state, and local
laws, ordinances, and policies pertaining to shoreline management.
It has been the National Park Service's long-term policy to let its managed dunes erode
and for the natural coastal processes to occur. However, the National Park Service also
permits, by regulation, the existence of a right-of-way on Hatteras Island for the purpose
of NCDOT maintenance of the highway. As such, the National Park Service strives to
allow for maintenance of the highway corridor while allowing the natural coastal
processes to continue. In addition, NC 12 provides the sole vehicular access through the
Seashore, and visitation to and enjoyment of the areas of the Seashore within and south of
the project area are largely dependent upon maintenance of the NC 12 corridor.
4. Natural Resources
The Seashore provides habitat for a wide variety of wildlife. Thirteen biotic
communities/habitats have been identified in the project area. A description of these
habitats is included in the “Biotic Communities” section of the Environmental
Assessment.
Thirteen federally listed protected species potentially occur within Dare County. Eight
have been documented in the project area and/or have suitable habitat within the project
area. Five of these species, the Atlantic leatherback sea turtle, the green sea turtle, the
hawksbill sea turtle, and the Kemp's ridley sea turtle, are occasional visitors to the waters of
the Cape Hatteras National Seashore area. The other species are the piping plover, roseate
tern, and seabeach amaranth. These findings have been affirmed through informal
consultation (Section 7) with the USFWS. Natural resources in the project area and
potential impacts associated with each alternative are described in detail in the
Environmental Assessment.
5. Impacts of Alternatives on the Cape Hatteras National Seashore
The alternatives under consideration are located within the Cape Hatteras National
Seashore, These alternatives are shown on Plates P-1 through P-7. A description of the
alternatives under consideration is provided below in Table 13. A more detailed of these
alternatives is included in the Environmental Assessment.
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TABLE 13. DESCRIPTION OF ALTERNATIVES, CONSTRUCTION FOOTPRINTS,
AND IMPACT ACREAGE
Construction Impact
Alternative Description Footprint Acreage
Required (acres)**
(feet)*
Alternative 1 – “No Build” Routine maintenance continues. None 0
Alternative 2 – Beach Extention of beach and formation
Nourishment of dunes using sand from off-shore; 105.9 121.7
road remains in existing location.
Alternative 5 – Road Relocate road only. Maintenance
Relocation of dunes continues, as needed, in 8.6 26.8
response to blow-outs during
storms.
Alternative 6 – Road Relocate road and build a dune to 32.1 61.1
Relocation with Dune minimize ocean overwash.
Alternative 7 – Road Relocate roadway. Protect roadway
Relocation with from severance by a cut in the 32.1 61.1
Subsurface Sandbags island by constructing sandbags
and Dune below ground. The dune will help
minimize overwash from ocean.
Alternative 8 – Road Relocate roadway. Protect roadway
Relocation with from severance by a cut in the
Sheetpiling and Dune island by constructing a sheet pile 32.1 61.1
walls below ground. The dune will
help minimize overwash from
ocean.
Alternative 9 – Road Relocate roadway. Protect roadway
Relocation with Surface from severance by a cut in the
Sandbags and Sand island by constructing sandbags 27.4 57.4
Covering above ground. The fortified dune
will help minimize overwash from
ocean.
Note: Alternative 3, 4, and 10 were eliminated from further study as they were determined to not meet the
intended purpose and need of the proposed project. (*multiply feet by 0.3048 to convert to meters, **multiply
acres by 0.4047 to convert to hectares)
The level of access to this resource provided by NC 12 will be maintained to some extent
by all alternatives under consideration. However, the “No Build” alternative is not
anticipated to survive the 7- to 10-year life expectancy of the project and, therefore, does
not meet the intended purpose of the proposed project.
The alternatives will require the permanent use of the Seashore. A summary of the
impacts by each alternative under consideration is shown in Table 12 in the
Environmental Assessment.
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While some impacts will occur to the Seashore, activities, features, or attributes of the
park resource will not be impaired substantially by the alternatives because:
NC 12 was planned to serve the park and the access it provides must be
maintained.
The alternatives under consideration will be in the same general corridor as the
existing roadway.
In the vicinity of the alternatives under consideration, natural systems will be affected.
Since all of the alternatives under consideration are wholly within the Cape Hatteras
National Seashore, the impacts discussed for the alternatives under consideration in the
Environmental Assessment are applicable to this discussion of impacts. The following
paragraphs summarize the Environmental Assessment’s findings on key Seashore-related
issues.
a) Facilities, Recreational Activities, and Scenery
The alternatives under consideration will not impact any existing facilities. No
new facilities or activities are planned by the National Park Service within or near
the proposed project area.
Access to the informal vehicular paths between NC 12 and the Pamlico Sound
will be impacted the alternatives that involve roadway relocation. In the event a
roadway relocation alternative is selected as the preferred alternative, NCDOT
will coordinate with the National Park Service regarding the reconnection of these
paths to NC 12.
The beach nourishment alternative will result in substantial changes in views from
the Seashore due to the creation 100-foot (30.5 meters) wide beach (beyond the
toe of the dune). Alternatives that include road relocation will also result in some
view changes. The relocated road will be up to 150 feet (45.7 meters) closer to
the Pamlico Sound than the existing road. Dunes will also be included with four
of the road relocation alternatives, which will result in some changes in the
viewshed from travelers on NC 12. None of the alternatives under consideration
will result in changed activities of the Seashore.
Carbon monoxide (CO) levels exceeding National Ambient Air Quality Standards
(NAAQS) will not be generated by any of the alternatives under consideration
The noise levels will not be exceeded at sensitive receptors with any of the
alternatives under consideration. No traffic noise abatement will be needed or is
proposed.
b) Coastal Conditions
The “build” alternatives under consideration are designed to maintain the integrity
and viability of the roadway with minimal interruption of traffic service due to a
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moderate storm event between Buxton and Avon for a period of 5-10 years until a
long-term solution is in place. As such, combinations of beach nourishment,
roadway relocation, dune construction, and other stabilization methods were
analyzed, including the use of sheet piling and sandbags (both subsurface and
above-ground sandbags).
Each alternative under consideration, except for the “No Build” alternative
(Alternative 1), provides some degree of protection of the access provided by the
highway. The access provided by the highway can be maintained by reducing the
amount of sand overwash on the roadway, the amount of ocean or soundside
flooding, or the potential for a severance of the roadway due to a cut through the
island. Features such as sandbags, sheetpiling, or even an increased beach profile
(as proposed under the Beach Nourishment alternative) provide increased
assurance against a severance of the roadway. Table 14, Summary of Potential
Impacts to Cape Hatteras National Seashore, lists each the alternatives under
consideration and if they are designed to allow natural coastal processes to
continue.
c) Natural Systems
The biotic community (excluding man-dominated areas) impacts within the
Seashore for the preferred alternatives are summarized in the Environmental
Assessment. No wetlands will be impacted by any of the alternatives under
consideration.
The alternatives under consideration will have a minimal effect on the birds using
Seashore lands. Dredging in the surf zone will cause temporary increases in
turbidity and potential decreases in dissolved oxygen levels within the immediate
vicinity of dredging activities. This temporary increase in sedimentation within
the immediate area of dredging will be temporary and short-term.
With the possible exception of the piping plover and loggerhead sea turtle,
protected species impacts are not expected. Informal consultation (Section 7)
with the USFWS resulted in the resolution of potential impacts and guidelines for
addressing each of the species that could occur potentially in the project area
(March 27, 2000 meeting minutes on USFWS Informal Consultation from Julie
A. Hunkins to file). The NCDOT and the FHWA will consult further on the
approach to avoiding or minimizing impacts to protected species as project design
progresses. A complete discussion of natural resource impacts in the
Environmental Assessment.
d) Construction
Construction of the alternatives under consideration and potential removal of the
existing road will be governed by NCDOT's Standard Specifications for Roads
and Structures (July 1995).
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A construction staging area may be required. If a construction staging area is
required, the NCDOT will coordinate with the NPS to identify sites if none can be
located outside the National Seashore boundaries.
Traffic will be maintained on NC 12 throughout construction. Construction
vehicles operating on NC 12 could cause motorists to encounter brief periods of
delay and disruption. A traffic control plan will be developed, as per current
criteria.
Overall, construction noise impacts will be minimal.
e) Summary of Impacts to Cape Hatteras National Seashore
Table 14 summarizes the potential impacts to the Cape Hatteras National
Seashore that are anticipated to occur as a result of each alternative. These
impacts do not include temporary impacts that may be realized during the
construction period. This assessment of impacts was developed collaboratively
with the National Park Service.
During construction, there may be some construction activities that preclude use
of areas of the beach or sound through the project area. For instance, construction
of a beach fill and dunes associated with the beach nourishment alternative and
periodic maintenance activities would impair use of the beach during the period of
time that sand is being pumped. Likewise, dune construction activities associated
with several of the alternatives under consideration would limit access to the
beach during construction. Continuous access along the informal vehicle paths on
between the existing roadway and the Pamlico Sound would be severed during
construction of alternatives that involve roadway relocation. Access to these
informal vehicular paths will be permitted to the sound as can be provided in a
safe and practicable manner.
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TABLE 14. SUMMARY OF POTENTIAL IMPACTS TO
CAPE HATTERAS NATIONAL SEASHORE
Recreation
Activity Beach Use Sound Use Natural
Sunbathing Windsurfing Scenery Natural Coastal
Beachcombing Swimming (Impact on Systems Processes
Swimming Outboarding Primary Flora Allowed to
Fishing Fishing Fauna
Viewsheds) Continue
Off-road Birding
Formation
Vehicles Off-road
of Inlets
Birding Vehicles
Overwash
Kayaking Kayaking
Alternative Canoeing
No Build Negligible or Negligible or Negligible Negative No
no effect no effect or effect
no effect
Beach No
Nourishment Negligible or Negligible or Negligible Negative
no effect no effect or effect
no effect
Road
Relocation Negligible or Negative effect Negligible Negligible Yes
no effect effect or
no effect
Road
Relocation w/ Negligible or Negative effect Negative Negative No
Dune no effect effect effect
Road
Relocation w/ Negligible or Negative effect Negative Negative No
Dune and no effect effect effect
Keyed-in
Sandbags
Road
Relocation w/ Negligible or Negative effect Negative Negative No
dune and no effect effect effect
sheetpiling
Road
Relocation w/ Negligible or Negative effect Negative Negative No
dune and no effect effect effect
surface
sandbags
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6. Avoidance Alternatives
All alternatives under consideration would involve the use of Cape Hatteras National
Seashore, including the “no build” alternative, which calls for routine maintenance to
continue as it has in the past in a reactive manner. The identification of avoidance
alternatives is difficult because the entire project area lies within this Section 4(f)
property. In addition, one of the principal functions of NC 12 is to provide access to the
Seashore on Hatteras and Ocracoke Islands. If NC 12 were severed and the access it
provides were not replaced, the ability of Seashore users to reach many of the Seashore
facilities and activities would be substantially impaired and the utility of the Seashore
would be diminished substantially. Furthermore, access to communities along NC 12,
especially those south of the project area, depend on this highway for their existence.
Potential avoidance options were considered: a bridge across Pamlico Sound from Avon
to Buxton or ferry service between Avon and Hatteras Inlet. The pros and cons of each
of the avoidance alternatives are provided below.
Bridge (across Pamlico Sound or from Avon to Buxton)
Pros
Avoids direct impacts to Seashore
Is considered a long-term option
Would eliminate need for continued maintenance of NC 12 and associated
impacts at project site
Cons
Long-term option – reaches far beyond the scope or purpose and need of the
proposed project; the bridging option between Avon and Buxton is being
considered as a long-term option to be in place by the end of the life
expectancy of this interim project.
Could reduce access to parts of the Seashore currently served by this portion
of NC 12, depending upon how existing roadway would be maintained and by
whom
Expensive (not a primary consideration under Section 4(f))
Ferry (between Avon and Hatteras Inlet)
Pros
Would eliminate need for continued maintenance of NC 12 and associated
impacts at project site
Cons
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Avon dock area too small; would require re-construction of ferry docks with
associated impacts (relocatees, wetlands, etc.)
Would increase time required to get from mainland to communities south of
project area, creating potential adverse economic impacts associated with
diminished access to the area
Impacts due to dredging in sound (SAV etc.)
7. Measures to Minimize Harm
The purpose of the project is to maintain the transportation access provided by NC 12
through the project area. In that NC 12 is the only vehicular access to and from the Cape
Hatteras National Seashore, loss of access through the project area would severely
diminish the public’s ability to use parts of the Seashore south of the project area.
Keeping NC 12 open and regularly accessible to the public and Seashore visitors is key to
the enjoyment and operation of the National Seashore.
Potential approaches to minimize harm to the Cape Hatteras National were considered.
They included:
Analysis of different roadway alignments to avoid wetland impacts
Analysis of different methods of providing protection to NC 12 (beach nourishment,
sheet piling, sandbags, and dunes)
Analysis of different dune heights and roadway elevations
Removal and restoration of the old roadway with native vegetation for road relocation
options
Use of contaminant-free sand and compatible sand for alternatives that involve beach
nourishment, dune construction, and/or sandbag installation.
Full comparison of alternatives with tradeoffs for impacts to the Seashore
8. Coordination
Consultation with the National Park Service (NPS) was initiated at the beginning of the
project development process. The NPS:
Provided information on the significance and use of the lands within their
jurisdictions. This information is presented in various sections in the
Environmental Assessment.
Were consulted in developing the assessment of impacts to recreational activities,
scenery, and natural systems, in addition to the determination of whether the
alternatives under consideration allow natural coastal processes to continue.
Were given the opportunity to participate in the project scoping processes.
Sent representatives to government officials meetings.
Sent representatives to the NEPA/404 Merger Team meetings.
Sent representatives to Outer Banks Task Force meetings where various issues
regarding the NC 12 corridor were discussed.
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Participated in a meeting addressing Section 7 issues.
Issues raised in connection with impacts, avoidance alternatives, and measures to
minimize harm were as follows:
Alternatives should be considered that will be compatible with the dynamic
nature of the coastal barrier island complex.
Resource impacts related to the construction and eventual removal of the
alternatives under consideration should be evaluated and discussed in the
Environmental Assessment.
Sand compatibility and sediment contamination analyses should be conducted
for material that is proposed for use as fill in sandbags, for dune construction,
or beach nourishment.
Construction methodology and associated potential impacts should be
assessed.
A vulnerability analysis of the three “hot spots” to the north should be made,
in addition to the project area, to ensure that the proposed alternatives are not
“over-designed” and to compare the accessibility through these areas during
and immediately following certain storm events.
The above issues are discussed in the Environmental Assessment.
VI. COMMENTS AND COORDINATION
A. Agency Coordination
The project has been coordinated with the appropriate federal, state, and local agencies. The
following meetings have been held at which this section of NC 12 has been discussed. The
minutes of these meetings are on file at the NCDOT and are posted on the official website of
the Outer Banks Task Force (www.obtf.org).
September 23, 1998 Outer Banks Task Force (OBTF) Meeting - Raleigh
Agencies Represented: U.S. Army Corps of Engineers, Federal Highway Administration,
National Park Service, U. S. Fish and Wildlife Service, National Marine Fisheries, N.C.
Department of Environment and Natural Resources, NCDOT, Dare County
Summary: An overview of the six critical areas along NC 12, including the proposed
project site, was presented. Consensus among the meeting participants is that contingency
plans are needed to address these vulnerable locations along NC 12 such that when and if
action is needed at these locations, possible solutions will be already defined and acceptable
to the OBTF.
November 16-17, 1998 Outer Banks Task Force Meeting and Field Trip - Manteo
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Agencies Represented: U.S. Army Corps of Engineers, Federal Highway Administration,
National Park Service, U. S. Fish and Wildlife Service, National Marine Fisheries, N.C.
Department of Environment and Natural Resources, NCDOT, Dare County, Hyde County,
Sierra Club, Senator Marc Basnight’s Office, local residents, Virginia Pilot
Summary: In addition to the OBTF meeting, most participants engaged in a field trip to
view the six critical areas, including the proposed project site. Short term and intermediate
alternatives for addressing erosion and overwash threats to NC 12 were discussed. A range
of study alternatives for each of the critical sections along NC 12 was established. The
range of alternatives, as reached by consensus, for the subject section of NC 12 included:
dune restoration, road relocation, sandbag installation, active dune management, and dune
re-vegetation. In addition, the following concerns were noted: compatibility of dredged
sand and native sand, time of year of nourishment/dune restoration activities, and the cost of
transporting the sand to the desired location.
February 11, 1999 Executive Committee for the Partnership for the Protection and
Maintenance of the Transportation System on N.C.’s Outer Banks Meeting - Raleigh
Agencies Represented: U.S. Army Corps of Engineers, National Park Service, U. S. Fish
and Wildlife Service, National Marine Fisheries, N.C. Department of Environment and
Natural Resources, NCDOT, Dare County, Hyde County, Senator Marc Basnight’s Office
Summary: Information on the critical areas along NC 12 was presented. A video of the
Outer Banks area depicted the fragile nature of the Outer Banks and the relationship of the
existing roadway to the ocean and sound. For each of the critical areas, information was
provided about the specific problems at the site and the range of alternatives the Task Force
has mutually developed. None of the Executive Committee members expressed an objection
about the range of alternatives currently under consideration for the critical areas, including
the subject project area.
March 10, 1999 Outer Banks Task Force Committee Meeting – Nags Head
Agencies Represented: U.S. Army Corps of Engineers, Federal Highway Administration,
National Park Service, U. S. Fish and Wildlife Service, National Marine Fisheries, N.C.
Department of Environment and Natural Resources, NCDOT, Dare County, Hyde County,
University of Arkansas, Biodiversity Legal Foundation, Virginia Pilot, Coastland Times
Summary: The Committee was briefed on the status of planning for the six critical area
improvements, including the subject project area. A summary sheet was provided giving a
description of each critical area, erosion rate at the site, range of alternatives to be studied
(as decided by the OBTF), and other pertinent information. Additionally, it was noted that
three of the critical areas, including the proposed project area, had received emergency
federal funding for dune repairs. The availability and compatibility of sand was also
discussed.
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June 1, 1999 Interagency Meeting – Raleigh
Agencies Represented: U. S. Fish and Wildlife Service, N.C. Wildlife Resources
Commission, National Parks Service, Dare County, N.C. Department of Environment and
Natural Resources, NCDOT
Summary: The purpose of the meeting was to discuss the attending agencies’ positions and
proposals regarding the proposed improvements at the six critical areas. The proposed
improvements for the subject section of NC 12 included dune construction and sandbag
installation. The agencies requested that a group of recognized coastal scientists analyze
effectiveness and the possible negative coastal process impacts of the new proposals at this
and other locations.
As a result of this request, NCDOT consulted with the US Fish and Wildlife Service and
National Park Service in putting together a scientific panel of experts to look at the proposed
immediate and interim measures to reduce the potential for road closure due to overwash, as
well as other possible alternatives.
June 14, 1999 Outer Banks Task Force Meeting - Edenton
Agencies Represented: U.S. Army Corps of Engineers, Federal Highway Administration,
National Park Service, U. S. Fish and Wildlife Service, National Marine Fisheries, N.C.
Department of Environment and Natural Resources, NCDOT, Dare County, Hyde County,
Virginia Pilot, N. C. Geological Survey, Senator Marc Basnight’s Office, N. C. State
University, area residents
Summary: The Committee was briefed on the status of the proposed improvements at the
six critical areas. It was noted that two storms occurred along the Outer Banks in May,
further worsening the conditions along NC 12. The proposed improvements concerning the
subject project location were presented as dune reconstruction and sandbag installation.
Interim improvements discussed included roadway relocation. It was also stated that the
subject project area was considered to be potentially the worst area on Hatteras Island, with
regards to ocean overwash and flooding. The Committee was also informed of the assembly
of the scientific research panel to study the six critical areas. A member of that panel
attended this meeting.
November 1, 1999 Outer Banks Task Force Meeting - Edenton
Represented Agencies: National Park Service, N.C. Department of Environment and Natural
Resources, U.S. Fish and Wildlife Service, NCDOT, Federal Highway Administration, U.S.
Army Corps of Engineers, National Marine Fisheries Service, Hyde County, N.C. State
University, Biodiversity Legal Foundation
Summary: The Task Force was updated on the status of the six “hot spots” and their
conditions after Hurricanes Dennis and Floyd in August and September. The Science Panel
also updated their recommendations for improvements to each site, including the subject
97
project area. Road relocation to the north and south of the newly relocated section of NC 12
north of Buxton was the interim recommendation from the panel. Beach nourishment was
discussed as an option for the subject area. It was decided that other options would also be
studied and included in any decision-making process and NEPA document
February 8, 2000 Outer Banks Task Force Meeting – Edenton
Represented Agencies: N.C. Department of Environment and Natural Resources, National
Park Service, U.S. Army Corps of Engineers, NCDOT, U.S. Fish and Wildlife Service,
Federal Highway Administration, Hyde County, Dare County, East Carolina University,
N.C. State University, Senator Marc Basnight’s office, Biodiversity Legal Foundation
Summary: Updates on the six critical areas were provided to the Task Force. It was
announced that the U.S. Army Corps of Engineers had been contracted to provide
engineering and planning services for interim improvements between Buxton and Avon.
Possible alternatives for the subject project were discussed, with descriptions of those
already being developed provided to the group.
May 11, 2000 Outer Banks Task Force Meeting – Manteo
Represented Agencies: N.C. Department of Environment and Natural Resources, National
Marine Fisheries Service, U.S. Fish and Wildlife Service, National Park Service, Federal
Highway Administration, U.S. Army Corps of Engineers, NCDOT, Dare County, Hyde
County, N.C. State University, University of Arkansas, University of Virginia, N.C. Sea
Grant, N.C. Department of Commerce, Biodiversity Legal Foundation, Defenders of
Wildlife, Virginia Pilot
Summary: The Task Force was informed that the NEPA/404 Project Team had reached
consensus on the purpose and need statement and range of alternatives for the subject
project in February. Preliminary results of the vulnerability study for the subject project
area were also presented. Based on the results, it was suggested that the Ash Wednesday
design storm be replaced with the 1991 Halloween Storm. The Task Force also discussed
the long-term study for the subject project area.
B. Public Coordination
As stated earlier, the proposed improvements were developed and discussed on many
occasions at the Outer Banks Task Force Meetings. Attendees of those meetings included
area residents as well as citizen-based organizations. Additionally, local and state elected
officials were in attendance, as well as local news representatives. The proposed
improvements have been discussed not only with state and federal agencies, but also by area
residents, citizen organizations, and elected officials who serve those citizens.
The public groups participating included local residents, the Biodiversity Legal Foundation,
Sierra Club, Dare County elected officials, Hyde County elected officials, North Carolina
Senate (Senator Marc Basnight’s Office), the Virginia Pilot, and the Coastland Times.
98
Additionally, the Outer Banks Task Force meetings have received considerable attention
from the local news media, resulting in many published news stories.
Another opportunity for public involvement will be accomplished by the distribution of this
document. Copies of this Environmental Assessment will be submitted to the State
Clearinghouse for distribution, and a notice will be published in the N.C. Environmental
Bulletin. The document will also be distributed to members of the Outer Banks Task Force
(OBTF) and people who have requested to be added to the OBTF mailing list. Upon request,
NCDOT will provide copies of the document to the public. Copies are available for public
viewing at NCDOT Raleigh and Division One offices; the State Clearinghouse office; local
government offices, including the local council of government office, and local public
libraries.
C. DISTRIBUTION OF ENVIRONMENTAL ASSESSMENT AND PUBLIC HEARING
This document is being coordinated and circulated with all agencies and persons known to
have an interest in the project area. In addition, a public hearing will be conducted to
provide the public with the opportunity to comment on the alternatives under consideration
for the proposed project.
VII. REFERENCES
Bent, Arthur C. 1928. Life histories of North American shorebirds. Vol. 2. Dover
Publications, Inc., N.Y. 412 pp.
Clark, M. K. 1987. West Indian Manatee. Pages 18-21 in: Endangered, threatened and
rare fauna of North Carolina Part I. A re-evaluation of the mammals (M. K. Clark,
editor). Occasional Papers of the North Carolina Biological Survey 1987-3.
Cutter G.R. Jr. and R.J. Diaz, 1998. Part 1: Benthic Habitats and Biological Resources
Off the Virginia Coast 1996 and 1997. In Final Report Environmental Studies
Relative to Potential Sand Mining in the Vicinity of The City of Virginia Beach,
Virginia. Minerals Management Service. 26pp. + Figures and Tables.
Dadswell, M. J., B. D. Taubert, T. S. Squiers, D. Marchette, and J. Buckley. 1984.
Synopsis of biological data on shortnose sturgeon, Acipenser brevirostrum LeSeur
1818. National Oceanic and Atmospheric Administration Technical Report
NMFS 14, Washington, DC.
Dare County. 1994. Dare County Land Use Plan. 1994 Update. Dare County, North
Carolina. 120 pp. + Appendices.
Day, J.H., J.G. Field, and M.P. Montgomery, 1971. The Use of numerical
methods to determine the distribution of benthic fauna across the
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continental shelf of North Carolina. Journal of Animal Ecology,
40;93-125
Everts, Craig H., Jeter P. Battley, Jr., and Peter N. Gibson. 1983. Shoreline Movements,
Report 1, Cape Henry, Virginia, to Cape Hatteras, North Carolina, 1849-1980,
Technical Report CERC-83-1, Coastal Engineering Research Center, U.S. Army
Engineer Waterways Experiment Station, Vicksburg, MS and National Ocean
Service, National Oceanic and Atmospheric Administration, U.S. Department of
Commerce, Rockville, MD.
Hettler, W. F., Jr., and D. L. Barker. 1993. Distribution and abundance of larval fishes at
two North Carolina inlets. Estuarine, Coastal and Shelf Science 37:161-179.
Inman, D. L. and Dolan, R. 1989. The Outer Banks of North Carolina: Budget of
sediment and inlet dynamics along a migrating barrier system. Journal of Coastal
Research. , v. 5, n.2, p. 193-237.
Jensen, Robert E.. 1983. Atlantic Coast Hindcast, Shallow-Water, Significant Wave
Information, WIS Report 9, U.S. Army Engineer Waterways Experiment Station,
Hydraulics Laboratory, Vicksburg, MS.
Pearson, Thomas G., C. S. Brimley, and H. H. Brimley. 1942. Birds of North Carolina.
North Carolina Department of Agriculture, Raleigh. 416pp.
Potter, Eloise F., J. F. Parnell, and R. P. Teulings. 1980. Birds of the Carolinas.
University of North Carolina Press, Chapel Hill. 408pp.
Ross, S. W. 1996. Surf zone fishes of the south Atlantic Bight. Section III, pp. 42-107.
In: Hackney, C. T., M. H. Posey, S. W. Ross and A. R. Norris (Eds.). A review
and synthesis of data on surf zone fishes and invertebrates in the South Atlantic
Bight and the potential impacts from beach nourishment. Report to the U. S.
Army Corps of Engineers. Wilmington, N.C. 111 pp.
Ross, S. W. and J. E. Lancaster. 1996. Movements of juvenile fishes using surf zone
nursery habitats and the relationship of movements to beach nourishment along a
North Carolina beach: Pilot project. Report to NOAA Office of Coastal Resource
Management and the U. S. Army Corps of Engineers. Wilmington, N.C. 31pp.
Schmidly, David J. 1981. Marine mammals of the southeastern United States coast and
the Gulf of Mexico. U. S. Fish and Wildlife Service - Office of Biological
Services Report No. 80/41. 165pp.
Schwartz, F. J. 1995. Florida manatees, Trichecus manatus (Sirenia:Trichechidae) in
North Carolina 1919-1994. Brimleyana 22:53-60.
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Schwartz, F. J., W. W. Hassler, J. W. Reintjes, and M. W. Street. 1977. Acipenser
brevirostrum LeSueur. Shortnose sturgeon. pp. 252-253, In: Cooper, J. E., S. S.
Robinson, and J. B. Funderburg (Eds.). 1977. Endangered and threatened plants
and animals of North Carolina. N.C. State Museum of Natural History, Raleigh,
N.C. 444 page3 + i-xvi.
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