HomeMy WebLinkAbout19930744 Ver 1_Complete File_19971123
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
W. Coleman Long
Environmental Resources Section
Department of the Army
Wilmington District, Corps of Engineers
P.O. Box 1890
Wilmington, North Carolina 28402-1890
Dear Mr. Long:
09?A
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D E H N R
20 October 1997 RECEIVED
(3C i 2 ,3, 1997
ENVIRON*NkA QE S
This letter provides comments on the Monitoring Report dated July 1997 for the
Morehead Army Reserve Center (ARC) Mitigation Project and on your letter dated 26
September 1997. It addresses concerns raised on your suggestion that the 2500 plants
(Spartina alterniflora) necessary for the replanting be obtained from adjacent marshes.
I feel that there is still sufficient time for plants to be grown commercially in a
greenhouse. The time for collecting seed is short (late in the season) but there should still
be enough available seed to grow the number of plants needed. Seeds could be planted in
January 1998 for site planting in April 1998. Greenhouse grown plants from locally
collected seed will survive and prevents destruction of natural stands of Spartina
alterniflora.
Having said this, I do not have a problem with plants being obtained from the
field if this is the only solution and as long as they are properly obtained. Plants should
be dug where there is a sandy substrate at an area where the marsh is advancing. The
ideal transplant is one 6"-10" high with a diameter of .25"-.50" and a good root system
present. Plants should be handled carefully, being planted shortly after having been dug.
Good transplants are not found in the marsh interior. Care should be taken to keep
impact of the donor site at a minimum. Ideally, plants should be obtained in a 50-75 mile
radius of the study site.
In reviewing the porewater chemistry data collected, I would be concerned with
the high pH (7.95-8.72) found in the wells. Although the salinity data does not support
this here, it could be a factor of high salinity at times. At any rate, pH of this range could
inhibit proper nutrient uptake for good plant growth, especially for phosphorus and some
micronutrients.
The final suggestion I would have is for the client to consider topdressing the
entire planted area with 10-10-10 fertilizer during the spring, especially if a slow release
fertilizer is not used at the time of planting. This would provide some nutrient
availability shortly after planting and during the early part of the growing season.
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-5083 FAX 919-733-9919
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
Topdressing is usually done as soon as the tide is off the planted area to provide
maximum time for uptake before the tide returns. Care should be made to use proper
rates (based on soil test results) and to not over fertilize.
If you have any questions about my comments and suggestions, please feel free to
contact me at (919) 733-5083 ext. 215. Thank you.
Sincerely,
Larry L. Cobbs
Wetlands Restoration Program
State of North Carolina
Department of Environment,
Health and Natural Resources • •
Division of Environmental Management
ftwook
James B. Hunt, Jr., Governor ? ? H N ?
Jonathan B. Howes, Secretary A. Preston Howard, Jr., P.E., Director
September 9, 1993
Col. Cajigal
U.S. Army Corps of Engineers
Wilmington District
P.O. Box 1890
Wilmington, N.C. 28402
_ Dear Mr. Cajigal:
Subject: Proposed fill in Wetlands or Waters
U.S. Army Reserve Center, Improvements and expansion
Carteret County
DEM Project # 93744
Upon review of your request for 401 Water Quality Certification to
dispose of about 150,000 cubic yards of material which are tributary to Calico
Creek for U.S. Army Reserve Center expansion located at Morehead City in
Carteret County as described in your submittal dated 26 August 1993, we have
determined that the proposed fill can be covered by General Water Quality
Certification No. 2668. A copy of the General Certification is attached.
This Certification may be used in qualifying for coverage under Corps of
Engineers' Nationwide Permit No. 16.
Additional conditions are that:
1.) Mitigation for impacts to 3.3 acres of estuarine
habitat will be conducted as described in the
mitigation plan transmitted in the 26 August 1993
letter. Monitoring and success criteria will be
as described in that plan.
2.) As-built plans and surveys will be sent to DEM,
Water Quality Section.
3.) All monitoring reports will be sent to DEM
including the NCDMF monitering of shellfish
rehabilitation areas.
If this Certification is unacceptable to you, you have the right to an
adjudicatory hearing upon written request within thirty (30) days following
receipt of this Certification. This request must be in the form of a written
petition conforming to Chapter 150B of the North Carolina General Statutes and
filed with the Office of Administrative Hearings, P.O. Box 27447, Raleigh,
N.C. 27611-7447. Unless such demands are made, this Certification shall be
final and binding.
If you have any questions, please contact John Dorney at 919-733-1786.
Sincerely,
P.E.
9 estop F1?Sw?d
3744.1tr
Attachment
cc: Wilmington District Co s of Engineers
Corps of Engineers Wilmington Field Office
Wilmington DEM Regional Office
Central Files
Ms. Trudy Wilder; COE-Wilmington
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-7015 FAX 919-733-2496
An Equal Opportunity Affirmative Acfion Employer 50% recycled/ 10% post-consumer paper
Jf
DEPARTMENT OF THE ARMY
Wilmington District, Corps of Enginee s 1 4
Post office Box 1890
Wilmington, North Carolina 28402-18 0„AT«i'p1D)S rsn. -v
Action ID No. 199401122
January 13, 1994-'-
PUBLIC NOTICE
NOTICE OF AVAILABILITY OF ENVIRONMENTAL ASSESSMENT (EA)
AND FINDINGS OF NO SIGNIFICANT IMPACT (FONSI)
THE UNITED STATES ARMY RESERVE CENTER (USARC), 120th ARCOM, 824th (Heavy
Boat) Transportation Company, Morehead City, North Carolina 28557 has applied
for a Department of the Army (DA) permit TO CONSTRUCT DOCKING AND MOORING
FAgILITIES, TO MAINTENANCE DREDGE AND LENGTHEN AN ACCESS CHANNEL, AND TO
DREDGE A TURNING BASIN IN CALICO CREEK TO SUPPORT ACTIVITIES OF THE RESERVE
CENTER AT MOREHEAD CITY, Carteret County, North Carolina.
The following description of the work is taken from data provided by the
applicant. Plans submitted with the application show construction at the
eastern end of the project of two 90-foot-wide by 190-foot-long.open pile
piers with concrete caps. Approximately 0.8 acres of uplands will be
converted to open water habitat as a result of this work. The portion of the
piers constructed on uplands will be bulkheaded. A 250 feet long by 15 feet
wide pier with two floating docks 85 feet long by 10 feet wide will be
constructed along the western shoreline of the project area. These facilities
will be utilized for docking Landing Craft, Marine Utility (LCU's) and a
Coastal Inland Harbor (CHI) boat. Three to seven pile mooring dolphins will
be placed adjacent to the docking piers and in the turning basin. (See
attached Figures 1 through 3.)
The Calico Creek channel will be dredged to an average width of 70 feet
for a distance of 4200 feet from the most western point of the North Carolina
State Ports Authority (SPA) property to a new 320-foot diameter turning basin.
New dredge work will impact an estimated 3.3 acres of shallow estuarine
bottom. All dredging will be to a depth of -14 foot mean low water.(m.l.w.),
which includes a -2 foot overdepth. Existing depths in the proposed new
dredging areas range between 0.1 and 2.5 feet m.l.w. in the turning basin and
between 0.1 to 10.0 feet m.l.w. depth in the creek channel. Depths in areas
to be maintenance dredged average -11.0 m.l.w.. (See attached Figures 4 and
5.)
The estimated 150,000 cubic yards of fine sandy dredged material
scheduled to be dredged in the fall/winter of 1994/95 will be disposed on a
previously used upland diked disposal site located on the north side of Radio
Island, adjacent to the causeway. When undertaken, maintenance material
(estimated at 40,000 cubic yards) will be disposed of on the north
side of Radio Island or within the existing Brandt Island upland disposal
site.
Additional work will consist of demolition/removal of the residential
structures within the project area, the existing maintenance office, the
bulkhead fronting Calico Creek, the concrete pier extending into Calico Creek,
a 50-foot section of the docking pier on the eastern end of the project on the
north side of the concrete loading ramp, and the concrete retaining wall on
the western end of the project. New upland construction will consist of an
Organizational Maintenance Shop/Area Maintenance Support Activity Shop
(OMS/AMSA), and a new USARC Administrative/Training Center. (See attached
Figure 6.)
-2-
The affected aquatic environment consists of 3.3 acres of shallow
estuarine habitat which includes 0.1 acre of oyster rock. Estuarine wetlands
within the project area consist of tidal marsh dominated by smooth cordgrass
(Spartina alterniflora). The transition zone in the mooring construction
areas is vegetated with saltgrass (Distichli:s spicata), saltmeadow hay
(Spartina patens), marsh pennywort (Hvdrocotvle umbellata), sea ox-eye
(Borrichia frutescens), and marsh fimbristylis (Fimbristylis spadicea). The
project area is devoid of submerged aquatic vegetation (SAV). (See attached
Figure 7.)
Mitigation for lost wetland resources will be through creation of tidal
marsh and shallow water estuarine bottom at a 2:1 ratio. The proposed
mitigation plan includes the restoration of 5.6 acres of estuarine habitat and
enhancement of 2 acres of offsite estuarine bottom by the placement of oyster
cultch. The proposed mitigation site is located within the general vicinity
of the project and is found within the greater Newport River estuary. (See
attached Figure 8.) This site is approximately 20 acres in size and has been
used as a disposal area at different times during the history of the Atlantic
Intracoastal Waterway. The proposed site has been filled well above the
height of mean-high-water (m.h.w.). The generalized method of wetland
construction will involve the removal of the fill materials to the level of
the layers.representing the original or desired wetland surface. The material
removed would be disposed of on the remaining upland portion of the 20 acre
mitigation site. The graded and leveled area would then be seeded and planted
with greenhouse-grown seedlings. (See attached Figure 9.)
The purpose of the work is to expand the existing facilities to (1)
facilitate command and control, training and administration and operational
supervision of water-oriented activities; (2) provide facilities capable of
supporting the maintenance requirements for the vessels under its command; and
(3) provide adequate facilities for access, docking and.loading/unloading of
watercraft. This project is considered to be an essential part of the U.S.
Army Reserve's mission of augmenting (becoming part of) the combat forces of
the United States during periods of national emergency/war.
The North Carolina Department of Environment, Health and Natural Resources
has authorized the work. A determination that the project is consistent with.
the North Carolina Coastal Area Management Act was issued May 12, 1993.
Approval of this permit will give Federal authorization for maintenance
dredging for a period of time not to exceed 10 years from the date of permit
issuance. The permittee will be required to present plans to the District
Engineer a minimum of 2 weeks prior to commencement of such maintenance work.
All maintenance would be performed in accordance with Federal, State, and
local permits and regulations governing such activities at the time the
maintenance is undertaken.
This application is being considered pursuant to Section 10 of the River
and Harbor Act of 1899 (33 U.S.C. 403) and Section 404 of the Clean Water Act
(33 U.S.C. 1344). Any person may request, in writing within the comment
period specified in this notice, that a public hearing be held to consider
this application. Requests for public hearing shall state, with
particularity, the reasons for holding a public hearing.
The District Engineer has consulted the latest published version of the
National Register of Historic Places for the presence or absence of registered
properties, or properties listed as being eligible for inclusion therein, and
this worksite is not registered property or property listed as being eligible
-3-
for inclusion in the Register. Consultation of the National Register
constitutes the extent of cultural resource investigations by the District
Engineer, and he is otherwise unaware of the presence of such resources.
Presently, unknown archeological, scientific, prehistorical, or historical
data may be lost or destroyed by work under the requested permit..
The District Engineer, based on available information, is not aware that
the proposed activity will affect species, or their critical habitat,
designated as endangered or threatened pursuant to the Endangered Species Act
of 1973.
The decision whether to issue a permit will be based on an evaluation of
the probable impacts, including cumulative impacts, of the proposed activity
- and its intended use on--t-he public interest. Evaluation of the probable
impacts which the proposed activity may have on the public interest requires a
careful weighing of all those factors which become relevant in each particular
case. The benefits which reasonably may be expected to accrue from the
proposal must be balanced against its reasonably foreseeable detriments. The
decision whether to authorize a proposal, and if so the conditions under which
it will be allowed to occur, are therefore determined by the outcome of the
general balancing process. That decision should reflect the national concern
for both protection and utilization of important resources. All factors which
may be relevant to the proposal must be considered including the cumulative
effects thereof. Among those are conservation, economics, aesthetics, general
environmental concerns, wetlands, cultural values, fish and wildlife values,
flood hazards and flood plain values (in accordance with Executive order
11988), land use, navigation, shore erosion and accretion, recreation, water
supply and conservation, water quality, energy needs, safety, food and fiber
production, mineral needs, considerations of property ownership, and, in
general, the needs and welfare of the people. For activities involving the
placement of dredged or fill materials in waters of the United States, a
permit will be denied if the discharge that would be authorized by such permit
would not comply with the Environmental Protection Agencies, 404(b)(.1)
guidelines. Subject to the preceding sentence and any other applicable
guidelines or criteria, a permit will be granted unless the District Engineer
determines that it would be contrary to the public interest.
An Environmetal Assessment (EA) pusuant to the National Environmental
Policy Act has been prepared for the project and was circulated for review and
comment on February 19, 1993. Comments received and minor changes to the
project have been incorporated into the Finding of No Significant Impact
(FNSI) scheduled to be signed by January 31, 1994. Copies of the EA or FNSI
can be obtained by contacting Ms. Trudy Wilder at telephone (910) 251-4581.
The North Carolina Division of Environmental Management (NCDEM) took
final action in the issuance of the Clean Water Act certification on September
9, 1993 (DEM Project #98744). They determined that the proposed fill was
covered by General Water Quality Certification No. 2668, conditioned that
mitigation is provided for 3.3 acres of estuarine wetland habitat and that
monitoring reports of the mitigation and as-built plans and surveys are sent
to that agency.
Information regarding the Clean Water Act certification may be reviewed
at the offices of the Environmental Operations Section, North Carolina
Division of Environmental Management (NCDEM); Salisbury Street, Archdale
Building, Raleigh, North Carolina. Copies of such materials will be furnished
to any person requesting copies upon payment of reproduction costs.
Written comments pertinent to the proposed work, as outlined above, will
be received in this office, Attention: Mr. Scott McLendon, until 4:15 p.m.,
February 12, 1994, or telephone (910) 251-4725.
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
P.O. BOX 1890
WILMINGTON, NORTH CAROLINA 28402-1890
IN REPLY REFER TO
Planning Division
August 26, 1993
p N 6N Od??•
AUG 3 119Si
ATER OUI`J_i r
Mr. John Dorney
Division of Environmental Management
North Carolina Department of Environment,
Health, and Natural Resources
Post Office Box 29535
Raleigh, North Carolina 27626-0535
Dear Mr. Dorney:
On behalf of the 120th Army Reserve Command (ARCOM), the U.S. Army Corps
of Engineers, Wilmington District, has developed a mitigation plan for the
Addition/Alteration - U.S. Army Reserve Center Organizational Maintenance Shop
and Area Maintenance Support Activity Shop, Morehead City, Carteret County,
North Carolina project. The mitigation plan is enclosed for your review and
formal response.
The proposed mitigation plan was developed in coordination with your
staff. The plan includes information provided by telephone in response to our
letter of July 8, 1993, and the subsequent interagency meeting in Morehead
City, North Carolina, on July 16, 1993. As described in the plan, the
proposed mitigation will involve the construction of a salt marsh/tidal creek
complex on the upland dredged material disposal island, plus the construction
of 2 acres of offsite oyster reef habitat. The oyster reef construction will
be performed in coordination with the North Carolina Shellfish Relay Program.
A Memorandum of Understanding will be prepared by the Wilmington District and
will be signed by both the 120th ARCOM and the North Carolina Division of
Marine Fisheries prior to the oyster reef construction.
The contract for the ARCOM project is scheduled to be awarded January
1994, with work beginning within 30 days afterward. The initial activities
will involve work on the uplands at the site. Construction activities below
mean high water (m.h.w.), including the pier and bulkhead complex, and
dredging and disposal will be performed between October 1994 and March 1995.
The mitigation site is in the process of being acquired and acquisition will
be completed prior to commencement of any construction activities below m.h.w.
It is proposed that the mitigation work will be performed under a separate
contract scheduled for award in March 1994. As discussed at the July 16,
1993, meeting, it may be necessary to complete the mitigation action after the
dredging and disposal have occurred so that planting can occur during the
optimal planting season of March-May.
4
-2-
The work satisfies the conditions of Nationwide Permit 33 CFR
330.5(a)(16), Return Water From Upland Contained Disposal Areas, and the
North Carolina Division of Environmental Management General Water Quality
Certification (GC) No. 2668. The Environmental Assessment and Finding of No
Significant Impact for this Nationwide Permit was completed on November 19,
1991, and GC No. 2668 was issued on January 21, 1992. Pursuant to GC
No. 2668, the enclosed application requests the use of the upland diked
disposal site located on the north end of Radio Island for the Morehead City
Army Reserve Center project.
We would appreciate receiving your response to the mitigation plan and
the Section 401 application within 2 weeks from the date of this letter to
allow the contract to stay on schedule. If you have any questions, please
contact Mrs. Trudy Wilder or Mr. Charles Wilson, Environmental Resources
Branch, at (919) 251-4581 or (919) 251-4746, respectively.
Sincerely,
George L. Cajigal
Colonel, Corps of Engineers
District Engineer
Enclosures
Copies Furnished (with enclosures):
?Mr. Ron Ferrell
Division of Environmental Management
North Carolina Department of Environment,
Health, and Natural Resources
Post Office Box 29535
Raleigh, North Carolina 27626-0535
Mr. Jim Gregson
Water Quality Section
Division of Environmental Management
North Carolina Department of Environment,
Health, and Natural Resources
127 Cardinal Drive Extension
Wilmington, North Carolina 28403
Mail Completed Application to:
Water Quality Planning
Division of Environmental Management
NC Department of Environment, Health,
and Natural Resources
P.O. Box 29535 Raleigh, NC 27626-1786
ATTN: MR. JOHN DORNEY
Ph. (919) 733-1786
DEM ID:
U.S. ARMY CORPS OF ENGINEERS
APPLICATION FOR 401 WATER QUALITY CERTIFICATION
1. DATE: August 26, 1993
2. NAME/ADDRESS: U.S. Army Corps of Engineers
Wilmington District
P.O. .Box 1890
Wilmington, North Carolina 28402-1890
3. RESPONSIBLE INDIVIDUAL: George L. Cajigal
Colonel, Corps of Engineers
District Engineer
4. NAME OF CORPS OF ENGINEERS CONTACT: Trudy Wilder/CESAW-PD-E
TELEPHONE: (919) 251-4581
5. TYPE OF APPLICATION:
Nationwide Permit (NWP) No. 16
General Certification (GC) No. 2668 issued on January 21, 1992
New Application
6. PROJECT NAME: Addition/Alteration - U.S. Army Reserve Center, Organizational
Maintenance Shop and Area Maintenance Support Activity Shop,
Morehead City, Carteret County, North Carolina
7. DESCRIPTION OF PROPOSED WORK: The proposed action involves the improvements
and expansion of the U.S. Army Reserve Center at Morehead City, North Carolina
as described in the previously furnished EA/FNSI. The project involves the
disposal of approximately 150,000 cubic yards of material from calico Creek
within the upland diked disposal site on the north side of Radio Island. The
upland diked disposal sites are designed to maximize solids retention.
8. PURPOSE OF PROPOSED WORK: The dredging of this segment of Calico Creek will
allow the safe navigation and mooring of the 1600 and 2000 series Landing Craft
Utility (LCU's).
9. PROPOSED ACTIVITY TO BEGIN: October 1994
10. DURATION OF ACTIVITY: 150 days
11. DISCHARGE OF:
X Dredged Material
Fill Material
12. LOCATION OF DISC GE:
Municipalit Morehead City, NC
County: Carte et ?-
Drainage Basin: `Wh1`°tLl yak River
Receiving Waters: Newport River
13. NATURE OF RECEIVING WATERS:
Type: Coastal
Nature: Salt
Direction of Flow: Variable
14. TYPE OF DISCHARGE INCLUDING CHEMICAL COMPOSITION: Predominantly fine, gray
sandy material with lesser amounts of silt will be discharged into the upland
diked disposal site. The effluent of the confined site will consist of water and
sediment particulates which have not settled.
15. PROJECTED FUTURE VARIATION IN THE NATURE OF THE DISCHARGE: Material dredged
during future maintenance events will vary insignificantly.
16. IS THIS PROJECT LOCATED IN A WATERSHED CLASSIFIED AS SA, HOW, OR ORW?
YES (circle one) % NO
17. NUMBER OF ACRES OR VOLUME OF WETLANDS IMPACTED BY THE PROPOSED PROJECT:
Filled:
Excavated: Reference the enclosed mitigation plan
Total Impacted:
18. STATE REASONS WHY THE APPLICANT BELIEVES THAT THIS ACTIVITY MUST BE CARRIED
OUT AS PLANNED. ALSO, NOTE MEASURES TAKEN TO MINIMIZE WETLAND IMPACTS: The
proposed disposal of dredged material is necessary to achieve the project
objective of allowing safe navigation and mooring of the LCU's at the Morehead
City Army Reserve Center. The enclosed mitigation plan has been developed to
offset the impacts to wetlands.
19. HAVE ANY SECTION 401 CERTIFICATES BEEN PREVIOUSLY REQUESTED FOR USE ON THIS
PROPERTY?
YES % NO IF YES, EXPLAIN:
I certify that all information contained herein or in support thereof is true and
correct to the best of my knowledge.
George L. Cajigal
Colonel, Corps of Engineers
District Engineer
DATE:
Attachments
For prompt processing, submit:
Seven (7) copies of completed application
Drawings of proposed dredge and disposal sites
copies of previous 401 Certifications
A'
MITIGATION PLAN
ADDITION/ALTERATION - U.S. ARMY RESERVE CENTER
ORGANIZATIONAL MAINTENANCE SHOP AND AREA MAINTENANCE SUPPORT ACTIVITY SHOP
MOREHEAD CITY, CARTERET COUNTY, NORTH CAROLINA
AUGUST 1993
MITIGATION PLAN
ADDITION/ALTERATION - U.S. ARMY RESERVE CENTER
ORGANIZATIONAL MAINTENANCE SHOP AND AREA MAINTENANCE SUPPORT ACTIVITY SHOP
MOREHEAD CITY, CARTERET COUNTY, NORTH CAROLINA
TABLE OF CONTENTS
ITEM
PAGE NO.
INTRODUCTION ......................................................... 1
MITIGATION GOALS AND OBJECTIVES ...................................... 1
PROJECT DESIGN ....................................................... 4
SITE DEVELOPMENT ..................................................... 5
Estuarine Habitat Restoration .................................... 5
Estuarine Habitat Enhancement .................................... 8
MONITORING ........................................................... 8
Construction Compliance .......................................... 9
Site Monitoring .................................................. 9
SUCCESS CRITERIA ..................................................... 9
COST ESTIMATE ........................................................ 9
LIST OF FIGURES
Figure 1: Mitigation Site ............................................ 2
Figure 2: Affected 'Environment .... .. ........................... 3
Figure 3: Mitigation Site Design, Plan View ........................ 6
Figure 4: Mitigation Site Design, Typical Section ................... 7
LIST OF TABLES
Table 1: Tidal Datum Relative to Corps of Engineers Mean Low Water. . 4
Table 2: Design Goals and Site Restrictions, Morehead ARC Mitigation. 5
i
MITIGATION PLAN
ADDITION/ALTERATION - U.S. ARMY RESERVE CENTER
ORGANIZATIONAL MAINTENANCE SHOP AND AREA MAINTENANCE SUPPORT ACTIVITY SHOP
MOREHEAD CITY, CARTERET COUNTY, NORTH CAROLINA
INTRODUCTION
On behalf of the 120th Army Reserve Command (ARCOM), the U.S. Army Corps
of Engineers (COE), Wilmington District, developed the following mitigation
plan for the Addition/Alteration - U.S. Army Reserve Center Organizational
Maintenance Shop and Area Maintenance Support Activity Shop, Morehead City,
Carteret County, North Carolina project.
As described in the Environmental Assessment and Finding of No Significant
Impact (EA/FONSI) dated February 1993, the proposed mitigation would involve
the construction of a salt marsh/tidal cr mplex on the upland dredged
material disposal island shown on F' o fset the loss of shallow
estuarine bottoms, oyster rock, d salt j?4 esulting from project
construction and maintenance. Un er the inalplan, it was assumed that
restoration of tidal marsh and shallow estuarine bottom at a 2:1 ratio would
require the restoration of 10 acres of habitat to offset 5 acres of resources
lost as a result of the project.
The Army Reserve Center (ARC) project was reviewed to identify
opportunities to minimize impacts and as a result was modified by moving the
proposed turning basin thereby reducing impacts to shallow estuarine bottoms
as shown on Figure 2. Habitat types impacted are the same as the original
plan; however, the impact area and associated mitigation requirements have
been reduced. Under the present plan, about 3.3 acres of estuarine habitat
would be impacted. At a 2:1 ratio, 6.6 acres of replacement habitat would be
required. Since these changes do not alter the findings of toe EA/FONSI, we
do not plan to recirculate it. The changes will be noted and furnished to all
concerned agencies and the public with the signed EA/FONSI.
Tidal datum, relative to COE mean low water (m.l.w.), is shown on Table 1.
This information is derived from data obtained from the National Ocean Survey
on 6 July 1993,' from a long-term (17 years) tidal station at Duke University
Marine Laboratory on Pivers Island.
MITIGATION GOALS AND OBJECTIVES
Objective. Our primary objective is to replace functional values
(specifically fish, shellfish, and wildlife habitat) associated with project
area estuarine resources including marsh, oyster rock, and shallow estuarine
bottom, which would be lost or significantly degraded as a result of the
construction of the ARC project.
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Table 1: Tidal Datum Relative to Corps of Engineers Mean Low Water.
Pivers Island, North Carolina
Tidal Datum Elevation
Estimated Highest Tide 9.14'
Mean High High Water 3.62'
Mean High Water 3.34'
National Geodetic Vertical Datum 1.54'
Mean Low Water 0.30'
Mean Low Low Water 0.14'
Corps Mean Low Water 0.00'
Estimated Lowest Tide -2.86'
Goals. Design goals and site restrictions including environmental and
engineering concerns for the restoration of estuarine habitat at the proposed
disposal island (Figure 1) were developed by the Wilmington District in
coordination with State and Federal regulatory agencies as shown on Table 2.
All elevations are based on COE dredging datum (i.e., COE m.l.w. is 1.54 feet
below National Geodetic Vertical Datum).
PROJECT DESIGN
A site design plan view based on these criteria is included as Figure 3.
A typical section is included as Figure 4. It is assumed that all excavated
area with a final elevation of +4 feet m.l.w. or less would be considered as
estuarine habitat restoration.
It was determined that the maximum area available for estuarine habitat
restoration, including wetlands and unvegetated intertidal and subtidal areas,
is about 5.6 acres., Regulatory agencies have indicated that since the
proposed restoration would not provide a full 2:1 replacement for resources
impacted, site expansion or additional alternative mitigation is required.
Expansion of the excavation area would require offsite disposal and/or
additional elevation in the disposal site. Offsite disposal of excavated
material would result in a significant incremental increase in project cost,
and excessive elevations in the disposal area may result in problems with
blowing sand. Site expansion would not meet the design criteria and is not
proposed.
It was determined that additional mitigation in the form of 2 acres of
estuarine enhancement by the placement of oyster cultch in coordination with
the North Carolina Shellfish Relay Program would fulfill the mitigation
deficit and was acceptable to resource agencies. This action would not result
in a significant increase in the the cost of the mitigation plan and-is
proposed for implementation.
4
Table 2: Design Goals and Site Restrictions, Morehead ARC Mitigation.
1. The general site configuration should result in development of a salt
marsh\tidal creek complex. Oyster cultch should be placed in selected
intertidal areas.
2. All areas to be excavated or receive fill should be above +5 m.l.w.
(with the exception of the tidal creek mouth) to avoid existing
wetlands generally found at or below +4 feet m.l.w. All available
upland areas should be utilized for site development up to a maximum
restoration area of 6.6 acres.
3. The site should be graded to drain.
4. Maximum fill elevations should not exceed +20 feet m.l.w., which
corresponds with existing maximum elevations at the site.
I
5. All excavated materials should be disposed of onsite.
6. A transitional area, including high marsh (Spartina patens) and
American beach grass (Ammophilia breviligulata), should be established
between the low marsh (Spartina alternaflora) and upland slopes.
7. Upland slopes should be stabilized and erosion control measures
implemented as appropriate.
SITE DEVELOPMENT
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The proposed mitigation plan includes the restoration of 5.6 acres of
estuarine habitat and enhancement of 2 acres of offsite estuarine bottom by
the placement of oyster cultch.
Estuarine Habitat Restoration
Site design components include a tidal creek, a transition zone, an upland
disposal area, and intertidal wetlands. Although the size of given areas and
proposed contours are identified in the plan, the long-term site configuration
will be based on natural stabilization processes and cannot be accurately
predicted.
Tidal Creek. A central branching creek covering an area of about 1.6
acres will be excavated below +1 feet m.l.w. The creek will be graded to
drain to a maximum depth at its mouth equal to the adjacent creek bottom.
5
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The expected maximum depth is about -2.5 feet m.l.w. About 1,000 bushels of
oyster cultch will be placed within unvegetated intertidal areas (between
elevations 0 m.l.w. and +1 m.l.w.).
Intertidal Wetlands. It is proposed that about 3.4 acres of the site will
be excavated to a depth between +1 feet m.l.w. and +3.5 feet m.l.w. to create
an area, adjacent to the tidal creek, that would occupy the approximate upper
two-thirds of the intertidal zone. This area would be planted with smooth
cordgrass (Spartina alterniflora) on 3-foot centers.
Transition Zone. A transition between elevations +3.5 feet m.l.w. and.
+5 feet m.l.w. (about 0.6 acres) acres will be excavated and planted in
saltmeadow hay (Spartina patens). An adjacent 25-foot-wide strip (0.6 acres)
of American Beach Grass (Ammophilia breviligulata) will be planted adjacent to
the saltmeadow hay along the toe of the disposal area slope, to form a buffer
between the marsh vegetation and adjacent uplands. Plants will be spaced 1.5
feet apart in rows spaced about 3 feet apart.
Upland Disposal Areas. Excavated materials will be disposed of on the
eastern side of the island. The fill elevation will not exceed +20 feet
m.l.w. Fill slopes adjacent to the marsh restoration will not exceed 6:1.
Other fill slopes will not exceed 3:1. Disposal area slopes, which are not
planted with American beach grass as described above, will be stabilized by
seeding with appropriate upland vegetation.
Erosion Protection. A sand fence will be installed to protect wetland
areas from wind-blown sand. Silt fences will be installed as needed.
Estuarine Habitat Enhancement
The North Carolina Division of Marine Fisheries (NCDMF), Shellfish
Rehabilitation Branch, will construct 2 acres of oyster reefs through cultch
planting. It is proposed that 10,000 bushels of cultch material will be
planted in selected areas totaling 2 acres. Rehabilitation efforts will be
located in the Newport River Estuary in areas identified by the NCDMF as
potentially productive oyster habitat. The NCDMF Support activities include
site selection, posting, and monitoring.
The project sponsor, 120th ARCOM, will fund the initial site construction.
The NCDMF will monitor and maintain the sites as a component of the North
Carolina Shellfish Rehabilitation Program. A Memorandum of Understanding will
be signed by both the 120th ARCOM and the NCDMF prior to the oyster reef
construction.
MONITORING
The estuarine restoration site will be monitored for the 120th ARCOM by
the Wilmington District or a qualified contractor to assess long-term site
conditions and potential remedial actions. The NCDMF will monitor the
estuarine enhancement sites in conjunction with shellfish rehabilitation
projects in the area.
8
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Construction Compliance
The site will be inspected and photo-docume
construction, bimonthly during construction, an
with contract documents will be assessed and a
Upon achieving the final grade, an as-built sur
the plans and specifications' intent has been
with the National Marine Fisheries Service pri
planting plan with documented quantities will
Site Monitoring
Site inspections and photo-documentation a
quarterly for the first year after constructs
will be assessed at the end of the first three
benthic samples will be taken at the site and
each year. A general comparison of estuarine
abundance at each site will be made. The stat
including collection of data on the number of
growth rate and average size of oysters on the
nted immediately prior to
d upon completion. Compliance
narrative report prepared.
vey will be made to assure that
met. The COE will coordinate
or to planting. An as-built
be provided by the contractor.
s described above will continue
on. Plant coverage by species
growing seasons. Fish and
at a nearby control site twice
species composition and relative
us of the shellfish population
oysters per piece of culteh,
site will also be made. An
annual monitoring report will be prepared.
SUCCESS CRITERIA
The contractor will be required to assure 80 percent survival of plant
materials at the end of the first growing season (September 30), if materials
are installed during optimal planting dates (March through May). A 12-month
assurance period would be required if plants are not installed during the
March through May dates. Up to one replacement planting will be required if
survival rate is not achieved. The site will be considered successful if at
the end of 3 years it has retained a general tidal creek/marsh configuration
and at least 4.5 acres (80 percent of the original 5.6 acres) are occupied by
wetlands (as defined by 404 ,jurisdiction) or shallow water habitat (i.e.,
areas less than -4 feet m.l.w.). .
COST ESTIMATE
It is estimated that cost for construction, maintenance, and monitoring of
this project would be about $700,000 to $800,000.
9