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Intent To Prepare a Draft Environmental Impact Statement (DEIS) for the Development of an Inlet Management Plan That Includes the Repositioning and Realignment of the Main Ebb Channel of Rich Inlet and To Use the Material To Nourish Figure Eight Island, North of Wilmington, New Hanover County, NC
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[Federal Register: February 26, 2007 (Volume 72, Number 37)]
[Notices]
[Page 8359-8361]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26fe07-60]
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DEPARTMENT OF DEFENSE
Department of the Army; Corps of Engineers
Intent To Prepare a Draft Environmental Impact Statement (DEIS)
for the Development of an Inlet Management Plan That Includes the
Repositioning and Realignment of the Main Ebb Channel of Rich Inlet and
To Use the Material To Nourish Figure Eight Island, North of
Wilmington, New Hanover County, NC
AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD.
ACTION: Notice of intent.
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SUMMARY: The U.S. Army Corps of Engineers (COE), Wilmington District,
Wilmington Regulatory Field Office has received a request for
Department of the Army authorization, pursuant to Section 404 of the
Clean Water Act and Section 10 of the Rivers and Harbor Act, from
Figure ``8'' Beach Homeowners Association to develop a management plan
for Rich Inlet that would mitigate chronic erosion on the northern
portion of Figure Eight Island so as to preserve the integrity of its
infrastructure, provide protection to existing development, and ensure
the continued use of the oceanfront beach along the northernmost three
miles of its oceanfront shoreline. Figure Eight Island is an
unincorporated privately developed island located on the southeast
coast of North Carolina, approximately eight miles north of Wilmington.
The island is bordered to the south by Mason Inlet and Wrightsville
Beach; and to the north by Rich Inlet and Lea-Hutaff Island, an
undeveloped, privately-owned island.
The inlet management plan would involve the repositioning and
realignment of the main ebb channel of Rich Inlet to a location closer
to the north end of Figure Eight Island. The intended alignment is to
be essentially perpendicular to the oceanfront shorelines of the
adjacent islands. The new channel position would be periodically
maintained with maintenance episodes dictated by natural shifts in the
channel position that produce unfavorable shoreline responses on the
north end of Figure Eight Island. While the main focus of the project
is to relocate the main ebb bar channel, consideration will also be
given to possible alterations in Nixon Channel and Green Channel to
determine if such modification would enhance the stability of the new
channel. Nixon Channel meanders along a southwesterly path on the landward
[[Page 8360]]
side of the north end of Figure Eight Island; connecting to the
Atlantic Intracoastal Waterway (AIWW) at a point approximately two
miles west of the Rich Inlet throat. Green Channel meanders to the
northeast on the landward side of Lea-Hutaff Island and intersects with
the AIWW approximately 1.75 miles north of the Rich Inlet throat.
Material dredged from the inlet and channels will be placed along
the central and northern portions of Figure Eight Island and, if
needed, along portions of Lea-Hutaff Island. The objective of the
placement of beach fill along the Figure Eight Island's shoreline is to
keep the design fill density less than 50 cubic yards/foot, to avoid
the placement of a permanent static vegetation line. This beach fill
would be maintained through a program of periodic beach nourishment
events with the material extracted from the dredging of Rich Inlet to
maintain the inlet in an optimum location.
DATES: A public scoping meeting for the Draft EIS will be held at Eaton
Elementary School, located at 6701 Gordon Road, on March 1, 2007 at 6
p.m. Written comments will be received until March 29, 2007.
ADDRESSES: Copies of comments and questions regarding scoping for the
Draft EIS may be addressed to: U.S. Army Corps of Engineers, Wilmington
District, Regulatory Division. ATTN: File Number 2006-41158-067, Post
Office Box 1890, Wilmington, NC 28402-1890.
FOR FURTHER INFORMATION CONTACT: Questions about the proposed action
and DEIS can be directed to Mr. Mickey Sugg, Wilmington Regulatory
Field Office, telephone: (910) 251-4811.
SUPPLEMENTARY INFORMATION:
1. Project Description. The Figure Eight Beach Homeowners
Association proposes to develop an inlet management plan for Rich Inlet
that will produce semi-permanent positive shoreline impacts on the
extreme north end of Figure Eight Island. Through a variety of
investigations, it has been determined that chronic erosion problems
along the northern sections of Figure Eight Island have been directly
linked to changes in the orientation and position of the main ebb
channel through Rich Inlet. When the main ebb channel of the inlet is
oriented toward the southeast or in the direction of Figure Eight
Island, and positioned close to the north end of the island, the
shoreline immediately south of the inlet tends to accrete. The
accretion is associated with the wave sheltering (``breakwater
effect'') provided by the south side of the ebb tide delta which also
moves with the channel. During periods in which the main bar channel
migrates to the north toward Lea-Hutaff Island and is oriented in a
southeasterly direction, the north end of Figure Eight Island erodes.
The northward movement of the main ebb channel is accompanied by the
northward shift of the south side of the ebb tide delta away from the
north end of Figure Eight Island, thus removing the ``breakwater
effect'' afforded by the south side of the ebb tide delta.
A geomorphic analysis of Rich Inlet will be performed utilizing
historical aerial photographs of Rich Inlet and the adjacent
shorelines. The geomorphic analysis will be used to develop alternative
channel positions and alignments that will assist in determining the
desired changes on the north end of Figure Eight Island. The analysis
will also assist in identifying any positive and/or negative impacts
associated with Lea-Hutaff Island. The position and alignment of the
main ebb channel design and design alternatives will be evaluated to
determine the potential effects on the adjacent shorelines and natural
resources located within the study area.
2. Proposed Action. The scope of activities for the formulation of
the management plan for Rich Inlet will include the following
engineering and geological investigations: (1) Detailed geomorphic
studies of the inlet and its impacts on the shorelines of Figure Eight
Island and Lea-Hataff Island; (2) numerical model simulations of
various channel alternatives including possible modifications of Nixon
and Green channels; (3) geotechnical investigations to determine
sediment quality in the inlet and connecting channels; (4)
compatibility analysis of the inlet material with the native beach
material; and (5) and analysis of the physical impacts of the project
on the inlet complex (including the adjacent marshes and connecting
channels) and on Figure Eight Island and Lea-Hutaff Island.
The Figure Eight Island beach fill design will consist of the
disposal material from Rich Inlet channel along the island shoreline in
a general template of a horizontal berm constructed to an elevation of
+6.0 feet NAVD (National Geodetic Vertical Datum) with a 1V:15H seaward
slope. The width of the berm, which would begin near the seaward toe of
the existing dune system, will depend on the volume of material removed
from Rich Inlet to construct the new channel and the slope the material
assumed during placement. Another design objective is to keep the
design fill density less than 50 cubic yards/foot, to avoid the
placement of a permanent static vegetation line. The volume of material
that would be removed to construct the new channel will depend on the
final design of the channel but could range between 500,000 cubic yards
and 2,000,000 cubic yards. Some of the channel material may be used to
construct or maintain the dune system on portions of Figure Eight
Island. Existing profiles will be analyzed to identify the range of
natural beach and dune elevations, widths, and slopes. The beach fill
design will include beach fill construction templates and equilibrium
cross-sections to estimate the seaward limit of cross-shore spreading
over the project life and the reduction in beach width due to changes
in profile shape following construction.
Beach planform performance will be evaluated based on the numerical
modeling for the proposed projects. The numerical model evaluation of
various channel alternatives will employ a process-based numerical
model known as Delft3D developed by WL Delft Hydraulics (WL Delft
Hydraulics, 2005). Delft3D is an advanced 2D/3D hydrodynamic model that
can simulate water level changes, currents, wave transformation,
sediment transport, and bathymetric (morphological) changes in coastal
environments. The model evaluations will consider short-term changes
(i.e., tidal cycles and storms) to the inlet's flow pattern and
morphology; as well as long-term (one to five years) changes in flow
patterns and inlet morphology associated with various inlet channel
alternatives. The model simulations will also be used to evaluate the
importance of modifications of Nixon and/or Green Channels on the
overall stability and associated impacts of the new channel.
Comprehensive geotechnical investigations of the Rich Inlet system
including the inlet throat, flood tidal delta, ebb tidal delta, and
feeder channels Nixon and Green Channel will be used to identify and
map sand quality and quantity to be placed on the shoreline of Figure
Eight Island or elsewhere as the study dictates. The proposed sand
search will be completed in two phases: (1) Research and planning, and
(2) jet probes and vibrance collection and analysis. Sand resources in
the study area will be evaluated for compatibility with native beach
sand. This evaluation is necessary to determine the potential
performance of sand on the beach since the performance is highly
dependent on similar sediment characteristics including mean grain
size, sorting, and
[[Page 8361]]
composition of borrow sands and native sands.
The research and planning phase includes a comprehensive analysis
of historical geophysical data, hydrographic survey data, and aerial
photographs of the inlet to determine potential channel shall lag
deposit sites and historic preferred channel alignment. The jet probe
survey will provide preliminary qualitative information of the sediment
contained in the feeder channels and the ebb tide delta of Rich inlet.
Areas suspected of containing the best quality and quantity of sand
resources within the preferred channel realignment corridor will be
targeted for vibracore investigation.
A magnetometer survey was performed on September 3, 2006 on the
wreck site of the Wild Dayrell. The Wild Dayrell is a side-wheel
steamer which ran aground near in the Rich Inlet complex on February 3,
1864. The location of the Wild Dayrell and its debris field will play a
major role in options associated with the location of the new inlet
channel. In addition, a cultural resource study of the final borrow
area and channel design will be performed using a magnetometer survey
controlled by differential global positioning. Cartographic and historical
research will be conducted to collect available historical data.
Natural resource studies and investigations which may be conducted
in support of the plan formulation might include: (1) Identification
and biological characterization of estuarine habitat types (salt march,
shelfish, submerged aquatic vegetation) in a defined project area using
aerial mapping and/or groundtruth investigations; (2) pre-project
monitoring of threatened and endangered species and their associated
habitats as determined through coordination with project stakeholders;
and (3) development and/or implementation of project monitoring and
mitigation plans based on the project impact assessment.
3. Issues. There are several potential environmental issues that
will be addressed in the EIS. Additional issues may be identified
during the scoping process. Issues initially identified as potentially
significant include:
a. Potential impacts to marine biological resources (benthic
organisms, passageway for fish and other marine life) and Essential
Fish Habitat, particularly within Green Channel.
b. Potential impacts to threatened and endangered marine mammals,
birds, fish, and plants.
c. Potential impacts to water quality.
d. Potential increase in erosion rates to adjacent Lea-Hutaff.
e. Potential impacts to Navigation, commercial and recreational.
f. Potential impacts to the long-term-management of Rich Inlet.
g. Potential impacts to private and public property.
h. Cumulative impacts of Inlet and Inlet channel relocations
throughout North Carolina.
i. Cumulative impacts for using inlets as sand source in
nourishment projects.
j. Potential impacts on public health and safety.
k. Potential impacts to recreational and commercial fishing.
l. The compatibility of the material for nourishment.
m. Potential impacts to cultural resources, particularly the Wild
Dayrell shipwreck.
4. Alternatives. Several alternatives are being considered for the
proposed project. These alternatives will be further formulated and
developed during the scoping process, and an appropriate range of
alternatives, including the no federal action alternative, will be
considered in the EIS.
5. Scoping Process. A public scoping meeting (see DATES) will be
held to receive public comment and assess public concerns regarding the
appropriate scope and preparation of the Draft EIS. Participation in
the public meeting by federal, state, and local agencies and other
interested organizations and persons is encouraged.
The COE will also be consulting with the U.S. Fish and Wildlife
Service under the Endangered Species Act and the Fish and Wildlife
Coordination Act; with the National Marine Fisheries Service under the
Magnuson-Stevens Act and Endangered Species Act; and with the North
Carolina State Historic Preservation Office under the National Historic
Preservation Act. Additionally, the EIS will assess the potential water
quality impacts pursuant to Section 401 of the Clean Water Act, and
will be coordinated with the North Carolina Division of Coastal
Management (DCM) to determine the project's consistency with the
Coastal Zone Management Act. The COE will closely work with DCM through
the EIS to ensure the process complies with all State Environmental
Policy Act (SEPA) requirements. It is the COE and DCM's intentions to
consolidate both NEPA and SEPA processes to eliminate duplications.
6. Availability of the Draft EIS. The Draft EIS is expected to be
published and circulated sometime in 2008, and a public hearing will be
held after the publication of the Draft EIS.
Dated: February 12, 2007.
John E. Pulliam, Jr.,
Colonel, U.S. Army District Commander.
[FR Doc. 07-848 Filed 2-23-07; 8:45 am]
BILLING CODE 3710-GN-M