HomeMy WebLinkAbout20151222 Ver 2_Application_20160219Carpenter,Kristi
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Rivenbark, Chris
Friday, February 19, 2016 2:14 PM
Tracey Wheeler (Tracey.L.Wheeler@usace.army.mil); Ward, Garcy
AI-Ghandour, Majed N; Brittingham, Cathy; Chapman, Amy; Daisey, Greg; Fritz Rohde
- NOAA Federal; gary�jordan@fws.gov; Jennings, Jerry D; Keith Hanson; Koch, Thomas
K; Carpenter,Kristi; Mellor, Colin; Staley, Mark K; Staples, Shane; Thomas, Roger D;
Wilson, Travis W.; Twisdale, John W; Ward, Garcy; Wilkins, Ronald B; Willis, Thomas C;
Feulner, Brett M; Griffin, Randy W; Paugh, Leilani Y; Turchy, Michael A; McCann, Nora
A; Herring, Kathy
Permit Application for B-2500 Habitat Enhancement Project, Dare County
Follow up
Flagged
The Nationwide 27 permit application for the B-2500 Phase I Habitat Enhancement Project has been prepared. The
electronic copy can be viewed/downloaded at https://xfer.services.ncdot.�ov/pdea/PermApps/B-2500/
This email serves as our permit application submittal to the U.S. Army Corps of Engineers and the N.C. Division of Water
Resources.
Chris Rivenbark
Project Development & Environmental Analysis
Natural Environment Section
North Carolina Department of Transportation
(919) 707-6152 office
crivenbark(cDncdot.qov
1598 Mail Service Center
Raleigh, NC 27699-1598
1020 Birch Ridge Drive
Raleigh, NC 27610
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Email correspondence to and from this sender is subject to the N.C. Public Records Law and may be disclosed to third parties.
Transportatian
February 19, 2016
U.S. Army Corps of Engineers
Regulatory Field Office
2407 West St'' Street
Washington, NC 27889
ATTN
Subj ect:
Dear Madam:
Ms. Tracey Wheeler
NCDOT Coordinator
PAT McCRORY
Covernor
NICHOLAS J. TENNYSON
Se�retary
Request for a Section 10 and Section 404 Nationwide 27 Permit for the Construction of a Habitat
Enhancement Project in the Pamlico Sound in Dare County.
NCDOT is requesting a Nationwide Permit 27 from the US Army Corps of Engineers to construct a habitat
enhancement project. Once complete, the "Reefinaker ecosystem" structure wi11 provide 0.3 acre of hard surface
habitat suitable for colonization by algae, oysters, and other sessile communities. The project will help satisfy
recent Coastal Area Management Act (CAMA) permitting requireinents for TIP No. B-2500 Phase I, WBS
Element 32635.1.3.
Please find the attached plan for the construction of the structure.
Construction of the structure will occur from barges and equipment will not dredge or be dragged on the sound
bottom. Impacts to the sound bottom will be limited to include the driving of piles, and the placement of the
structure itsel£ The proposed 500 ft. long by 4.79 ft. wide Reefmaker structure is estimated to have a 0.06 ac
(2,500 sq. ft.) benthic footprint.
It is anticipated that any SAV impacts during construction will be offset by relocation into the forecast wave
shadow of the structure.
Monitoring
Monitoring of the site will be conducted for a period of up to 5 years following installation of the wavebreak
structure, and will include monitoring of wave energy, seagrass, structure/hard surface, and sediment elevation. A
detailed monitoring plan is in the attached plan.
In the event the structure does not perform as intended, after the Sth year of monitoring, or at final close-out, if
requested by all of the resource agencies, NCDOT will remove this structure.
Proposed Let Date
Construction of tbe structure may begin as soon as all permits are received.
�Nat'hing Campares�_�_.
State of North Carolina I Department of TransportaYion I Project DevelopmenC and Environmental Anatysis
1000 Birch Ridge Drive � 1548 Mai] Service Center I Raleigh, NC 27699-1548
919-707-6000
Regulatory Approvals
Section 404 Permit: Issuance of a Nationwide Permit 27 is hereby requested for the above described activity.
Section 401 Certification: We anticipate 401 General Certification number 3885 will apply to this project.
NCDOT is requesting written concurrence from the North Carolina Department of Environmental Quality,
Division of Water Resources.
CAMA: Modification of the existing CAMA permit was requested under separate cover on October l, 2015.
The modifcation was issued on December 15, 2015.
A copy of this request and its distribution list will be posted on the NCDOT Website at:
https://connect.ncdot.gov/resources/Environmental. If you have any questions or need additional information,
contact Michael Turchy at maturchvnao,ncdot. o�v or 919 707-6157.
Sincerely,
_���'%/ � _
�
�� Richard W. Hancock, P.E., Manager
Project Development and Environmental Analysis Unit
cc: NCDOT Permit Application Standard Distribution List
Office Use Only:
Corps action ID no.
DWQ project no.
Form Version 1.4 January 2009
Pre-Construction Notification PCN Form
A. Applicant Information
1. Processing
1 a. Type(s) of approval sought from the
Corps: � Section 404 Permit � Section 10 Permit
1b. Specify Nationwide Permit (NWP) number: 27 or General Permit (GP) number:
1c. Has the NWP or GP number been verified by the Corps? � Yes ❑ No
1d. Type(s) of approval sought from the DWQ (check all that apply):
� 401 Water Quality Certification — Regular ❑ Non-404 Jurisdictional General Permit
❑ 401 Water Quality Certification — Express ❑ Riparian Buffer Authorization
1 e. Is this notification solely for the record For the record only for DWQ 401 For the record only for Corps Permit:
because written approval is not required? Certification:
❑ Yes � No ❑ Yes � No
1f. Is payment into a mitigation bank or in-lieu fee program proposed for mitigation � Yes � No
of impacts? If so, attach the acceptance letter from mitigation bank or in-lieu
fee program.
1g. Is the project located in any of NC's twenty coastal counties. If yes, answer 1 h � Yes ❑ No
below.
1 h. Is the project located within a NC DCM Area of Environmental Concern (AEC)? � Yes ❑ No
2. Project Information
2a. Name of project: Construction of a Habitat Enhancement Project
2b. County: Dare
2c. Nearest municipality / town: Rodanthe
2d. Subdivision name: n/a
2e. NCDOT only, T.I.P. or state B_2500 Phase I
project no:
3. Owner Information
3a. Name(s) on Recorded Deed: North Carolina Department of Transportation
3b. Deed Book and Page No.
3c. Responsible Party (for LLC if
applicable):
3d. Street address: 1598 Mail Service Center
3e. City, state, zip: Raleigh, NC 27699-1598
3f. Telephone no.: 919-707-6157
3g. Fax no.: 919-212-5785
3h. Email address: maturchy@ncdot.gov
Page 1 of 10
4. Applicant Information (if different from owner)
4a. Applicant is: ❑ Agent ❑ Other, specify:
4b. Name:
4c. Business name
(if applicable):
4d. Street address:
4e. City, state, zip:
4f. Telephone no.:
4g. Fax no.:
4h. Email address:
5. Agent/Consultant Information (if applicable)
5a. Name:
5b. Business name
(if applicable):
5c. Street address:
5d. City, state, zip:
5e. Telephone no.:
5f. Fax no.:
5g. Email address:
Page 2 of 10
B. Project Information and Prior Project History
1. Property Identification
1a. Property identification no. (tax PIN or parcel ID): n/a
1 b. Site coordinates (in decimal degrees): Latitude: 35.75084041 Longitude: - 75.58649065
(DD.DDDDDD) (-DD.DDDDDD)
1 c. Property size: Approximately 57 acres
2. Surface Waters
2a. Name of nearest body of water (stream, river, etc.) to pamlico Sound
proposed project:
2b. Water Quality Classification of nearest receiving water: SA HQW
2c. River basin: Pasquotank
3. Project Description
3a. Describe the existing conditions on the site and the general land use in the vicinity of the project at the time of this
application:
The project area is in Pamlico Sound. It is adjacent to a natural barrier island and estuarine system, with
recreation in Pea Island National Wildlife Refuge and Cape Hatteras National Seashore.
3b. List the total estimated acreage of all existing wetlands on the property:
This structure is located in open water. No wetlands are located in the study area.
3c. List the total estimated linear feet of all existing streams (intermittent and perennial) on the property:
n/a
3d. Explain the purpose of the proposed project:
To construct a habitat enhancement project. Once complete, the "Reefmaker ecosystem" structure will provide
0.3 acre of hard surface habitat suitable for colonization by algae, oysters, and other sessile communities. The
project will help satisfy recent Coastal Area Management Act (CAMA) permitting requirements.
3e. Describe the overall project in detail, including the type of equipment to be used:
All current permit conditions for B-2500 will be adhered to. Construction will be predominantly off of barges and
include the driving of piles into the water bottom substrate. Cranes will be used to lower structure components
onto the supporting piles. Construction equiment will not drag or rest on the water bottom.
4. Jurisdictional Determinations
4a. Have jurisdictional wetland or stream determinations by the
Corps or State been requested or obtained for this property /
project (including all prior phases) in the past? � Yes ❑ No ❑ Unknown
Comments:
4b. If the Corps made the jurisdictional determination, what type
of determination was made? ❑ Preliminary � Final
4c. If yes, who delineated the jurisdictional areas? Agency/Consultant Company:
Name (if known): Other: USACE
4d. If yes, list the dates of the Corps jurisdictional determinations or State determinations and attach documentation.
SAW-2015-02207
5. Project History
5a. Have permits or certifications been requested or obtained for � Yes ❑ No ❑ Unknown
this project (including all prior phases) in the past?
5b. If yes, explain in detail according to "help file" instructions.
NWP 6 issued 10/22/2015
6. Future Project Plans
6a. Is this a phased project? ❑ Yes � No
6b. If yes, explain.
Page 3 of 10
C. Proposed Impacts Inventory
1. Impacts Summary
1 a. Which sections were completed below for your project (check all that apply):
❑ Wetlands ❑ Streams - tributaries ❑ Buffers
� Open Waters ❑ Pond Construction
2. Wetland Impacts
If there are wetland impacts proposed on the site, then complete this question for each wetland area impacted.
2a. 2b. 2c. 2d. 2e. 2f.
Wetland Type of
impact Type of Type of wetland Forested jurisdiction Area of impact (acres)
number — impact (if known) (Corps - 404,
Permanent (P) 10
or Temporary DWQ — non-
T 404, other
W 1 ❑ P❑ T ❑ Yes ❑ Corps
❑ No ❑ DWQ
W2 ❑ P❑ T ❑ Yes ❑ Corps
❑ No ❑ DWQ
W3 ❑ P❑ T ❑ Yes ❑ Corps
❑ No ❑ DWQ
2g. Total wetland impacts
2h. Comments:
3. Stream Impacts
If there are perennial or intermittent stream impacts (including temporary impacts) proposed on the site, then complete this
question for all stream sites impacted.
3a. 3b. 3c. 3d. 3e. 3f. 3g.
Stream impact Type of Stream name Perennial (PER) or Type of Average stream width Impact
number - impact intermittent (INT)? jurisdiction (feet) length
Permanent (P) (Corps - (linear
or Temporary 404, 10 feet)
�T) DWQ —
non-404,
other)
S1 ❑ P❑ T ❑ PER ❑ Corps
❑ INT ❑ DWQ
S2 ❑ P❑ T ❑ PER ❑ Corps
❑ INT ❑ DWQ
S3 ❑ P❑ T ❑ PER ❑ Corps
❑ INT ❑ DWQ
S4 ❑ P❑ T ❑ PER ❑ Corps
❑ INT ❑ DWQ
S5 ❑ P❑ T ❑ PER ❑ Corps
❑ INT ❑ DWQ
S6 ❑ P❑ T ❑ PER ❑ Corps
❑ INT ❑ DWQ
3h. Total stream and tribatary impacts
3i. Comments:
Page 4 of 10
4. Open Water Impacts
If there are proposed impacts to lakes, ponds, estuaries, tributaries, sounds, the Atlantic Ocean, or any other open water of the
U.S. then individually list all open water impacts below.
4a. 4b. 4c. 4d. 4e.
Open water Name of
impact waterbody Type of impact Waterbody type Area of impact
number — (if (acres)
Permanent (P) applicable)
or Temporary
T
Fill
Pamlico insertion of iles to su ort habitat 0.06 ac or
01 � P❑ T Sound (enhancement project/ pReefmaker Open Water �2,500 sq. ft.)
Ecosystem" structure.
02 ❑P❑T
03 ❑P❑T
04 ❑P❑T
4f. Total open water impacts 0.06 ac or
(2,500 sq. ft.)
4g. Comments:
5. Pond or Lake Construction
If pond or lake construction proposed, then complete the chart below.
5a. 5b. 5c. 5d. 5e.
Wetland Impacts (acres) Stream Impacts (feet) Upland
Pond ID Proposed use or (acres)
number purpose of pond
Flooded Filled Excavated Flooded Filled Excavated Flooded
P1
P2
Sf. Total
5g. Comments:
5h. Is a dam high hazard permit
required? ❑ Yes ❑ No If yes, permit ID no:
5i. Expected pond surFace area
(acres):
5j. Size of pond watershed
(acres):
5k. Method of construction:
Page 5 of 10
6. Buffer Impacts (for DWQ)
If project will impact a protected riparian buffer, then complete the chart below. If yes, then individually list all buffer impacts
below. If an impacts require mitigation, then ou MUST fill out Section D of this form.
6a.
❑ Neuse ❑ Tar-Pamlico ❑ Other:
Project is in which protected basin? ❑ Catawba ❑ Randleman
6b. 6c. 6d. 6e. 6f. 6g.
Buffer impact
number — Reason Buffer mitigation Zone 1 impact (square Zone 2 impact
Permanent (P) for Stream name required? feet) (square feet)
or Temporary impact
T
B1 ❑P❑T ❑Yes
❑ No
B2 ❑P❑T ❑Yes
❑ No
B3 ❑P❑T ❑Yes
❑ No
6h. Total buffer impacts
6i. Comments:
D. Impact Justification and Mitigation
1. Avoidance and Minimization
1a. Specifically describe measures taken to avoid or minimize the proposed impacts in designing project.
The design selected minimizes the benthic footprint of the structure.
It is anticipated that any SAV impacts during construction will be offset by relocation into the forecast wave
shadow of the structure.
Other rip-rap structures were considered, but would have would have larger footprints on the sound bottom,
and less surface area for colonization.
1 b. Specifically describe measures taken to avoid or minimize the proposed impacts through construction techniques.
NCDOT will implement "Guidelines for Avoiding Impacts to the West Indian Manatee, Precautionary Measures
for Construction Activities in North Carolina Waters," during work for this project.
Due to the location and scope of the proposed work, federally-protected turtles will not be affected by project
construction. However to ensure their protection, moving equipment will be immediately shutdown if a turtle
is observed within 50 feet of the operational area of the equipment. Activities will not resume until the turtle
has departed the project area on its own volition (i.e., it may not be herded or harassed from the area).
Construction of the structure will occur predominantly from barges. No structure or equipment will drag on
the water bottom.
In the event the structure does not perform as intended, after the 5�'' year of monitoring, or at final close-out, if
requested by all of the resource agencies, NCDOT will remove this structure.
2. Compensatory Mitigation for Impacts to Waters of the U.S. or Waters of the State
2a. Does the project require Compensatory � Yes � No
Mitigation for impacts to Waters of the U.S. or
Waters of the State?
2b. if yes, mitigarion is required by (check all that
apply): ❑ DWQ ❑ Corps
❑ Mitigation bank
2c. If yes, which mitigation option will be used for
this project? ❑ Payment to in-lieu fee program
❑ Permittee Responsible Mitigation
Page 6 of 10
3. Complete if Using a Mitigation Bank
3a. Name of Mitigation Bank:
3b. Credits Purchased (attach receipt and letter) Type Quantity
3c. Comments:
4. Complete if Making a Payment to In-lieu Fee Program
4a. Approval letter from in-lieu fee program is ❑ Yes
attached.
4b. Stream mitigation requested: linear feet
4c. If using stream mitigation, stream ❑ warm ❑ cool ❑cold
temperature:
4d. Buffer mitigation requested (DWQ only): square feet
4e. Riparian wetland mitigation requested: acres
4f. Non-riparian wetland mitigation requested: acres
4g. Coastal (tidal) wetland mitigation requested: acres
4h. Comments:
5. Complete if Using a Permittee Responsible Mitigation Plan
5a. If using a permittee responsible mitigation plan, provide a description of the proposed mitigation plan.
6. Buffer Mitigation (State Regulated Riparian Buffer Rules) — required by DWQ
6a. Will the project result in an impact within a protected riparian ❑ Yes � No
buffer that requires buffer mitigation?
6b. If yes, then identify the square feet of impact to each zone of the riparian buffer that requires mitigation. Calculate the
amount of mitigation required.
6c. 6d. 6e.
Zone Reason for Total impact Multiplier Required mitigation
impact (square feet) (square feet)
Zone 1 3 (2 for
Catawba)
Zone 2 1.5
6f. Total buffer mitigation required:
6g. If buffer mitigation is required, discuss what type of mitigation is proposed (e.g., payment to private mitigation bank,
permittee responsible riparian buffer restoration, payment into an approved in-lieu fee fund).
6h. Comments:
Page 7 of 10
E. Stormwater Management and Diffuse Flow Plan (required by DWQ)
1. Diffuse Flow Plan
1 a. Does the project include or is it adjacent to protected riparian buffers identified � Yes � No
within one of the NC Riparian Buffer Protection Rules?
1 b. If yes, then is a diffuse flow plan included? If no, explain why.
❑ Yes ❑ No
Comments:
2. Stormwater Mana ement Plan
2a. What is the overall percent imperviousness of this project? n/a %
2b. Does this project require a Stormwater Management Plan? ❑ Yes � No
2c. If this project DOES NOT require a Stormwater Management Plan, explain why:
2d. If this project DOES require a Stormwater Management Plan, then provide a brief, narrative description of the plan:
n/a
❑ Certified Local Government
2e. Who will be responsible for the review of the Stormwater Management Plan? ❑ DWQ Stormwater Program
❑ DWQ 401 Unit
3. Certified Local Government Stormwater Review
3a. In which local governmenYs jurisdiction is this project? n/a
❑ Phase II
3b. Which of the following locally-implemented stormwater management programs ❑ NSW
apply (check all that apply): ❑ USMP
❑ Water Supply Watershed
❑ Other:
3c. Has the approved Stormwater Management Plan with proof of approval been ❑ Yes ❑ No
attached?
4. DWQ Stormwater Program Review
❑ Coastal counties
❑ HQW
4a. Which of the following state-implemented stormwater management programs apply � ORW
(check all that apply): ❑ Session Law 2006-246
❑ Other: N/A
4b. Has the approved Stormwater Management Plan with proof of approval been
attached? ❑ Yes ❑ No n/a
5. DWQ 401 Unit Stormwater Review
5a. Does the Stormwater Management Plan meet the appropriate requirements? ❑ Yes ❑ No
5b. Have all of the 401 Unit submittal requirements been met? ❑ Yes ❑ No
Page 8 of 10
F. Supplementary Information
1. Environmental Documentation (DWQ Requirement)
1a. Does the project involve an expenditure of public (federal/state/local) funds or the � Yes ❑ No
use of public (federal/state) land?
1 b. If you answered "yes" to the above, does the project require preparation of an
environmental document pursuant to the requirements of the National or State � Yes ❑ No
(North Carolina) Environmental Policy Act (NEPA/SEPA)?
1 c. If you answered "yes" to the above, has the document review been finalized by the
State Clearing House? (If so, attach a copy of the NEPA or SEPA final approval
letter.) � Yes ❑ No
Comments: NEPA FEIS/EA/ROD for TIP B-2500
2. Violations (DWQ Requirement)
2a. Is the site in violation of DWQ Wetland Rules (15A NCAC 2H .0500), Isolated
Wetland Rules (15A NCAC 2H .1300), DWQ Surface Water or Wetland Standards, ❑ Yes � No
or Riparian Buffer Rules (15A NCAC 2B .0200)?
2b. Is this an after-the-fact permit application? ❑ Yes � No
2c. If you answered "yes" to one or both of the above questions, provide an explanation of the violation(s):
3. Cumulative Impacts (DWQ Requirement)
3a. Will this project (based on past and reasonably anticipated future impacts) result in � Yes � No
additional development, which could impact nearby downstream water quality?
3b. If you answered "yes" to the above, submit a qualitative or quantitative cumulative impact analysis in accordance with the
most recent DWQ policy. If you answered "no," provide a short narrative description.
4. Sewage Disposal (DWQ Requirement)
4a. Clearly detail the ultimate treatment methods and disposition (non-discharge or discharge) of wastewater generated from
the proposed project, or available capacity of the subject facility.
Not applicable.
Page 9 of 10
5. Endangered Species and Designated Critical Habitat (Corps Requirement)
5a. Will this project occur in or near an area with federally protected species or � Yes ❑ No
habitat?
5b. Have you checked with the USFWS concerning Endangered Species Act � Yes ❑ No
impacts?
� Raleigh
5c. If yes, indicate the USFWS Field Office you have contacted.
❑ Asheville
5d. What data sources did you use to determine whether your site would impact Endangered Species or Designated Critical
Habitat?
USFWS website and agency consultation; NCDOT Biologists; FEIS/ROD
6. Essential Fish Habitat (Corps Requirement)
6a. Will this project occur in or near an area designated as essential fish habitat? � Yes ❑ No
6b. What data sources did you use to determine whether your site would impact Essential Fish Habitat?
NMFS county index; FEIS/ROD
7. Historic or Prehistoric Cultural Resources (Corps Requirement)
7a. Will this project occur in or near an area that the state, federal or tribal
governments have designated as having historic or cultural preservation � Yes ❑ No
status (e.g., National Historic Trust designation or properties significant in
North Carolina history and archaeology)?
7b. What data sources did you use to determine whether your site would impact historic or archeological resources?
NEPA documentation; FEIS/ROD
8. Flood Zone Designation (Corps Requirement)
8a. Will this project occur in a FEMA-designated 100-year floodplain? � Yes ❑ No
8b. If yes, explain how project meets FEMA requirements: This activity will not result in changes in permanent flood
elevations.
8c. What source(s) did you use to make the floodplain determination? approved NEPA documents
�Richard W. Hancock, P.E. _ — �_ /c� Z p j6
r '�
Applicant/AgenYs Printed Name ApplicanUAgent's Signature Date
(Agent's signature is valid only if an authorization letter from the applicant
is rovided.
Page 10 of 10
STI P B-2500
BONNER BRIDGE
PHASE I SAV MITIGATION PLAN
PAMLICO SOUND, OREGON INLET
DARE COUNTY
NORTH CAROLINA
September 2015
1.0
1.1
1.2
2.0
3.0
4.0
5.0
6.0
7.0
STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
Table of Contents
Introduction& Background ................................................................................................1
ProjectObjective ...........................................................................................................1
ExistingConditions ........................................................................................................1
ProposedMitigation Plan ..................................................................................................2
Construction Implementation and Methodology ................................................................4
Monitoring.........................................................................................................................6
Remediation and Long-Term Management ......................................................................8
MltigationSummary ..........................................................................................................8
References........................................................................................................................ 9
List of Tables
Table 1. Seagrass and elevation survey results ...........................................................................2
Table 2. 500-foot Reefmaker structure surface area calculations ................................................3
Table 3. Types of vessels used during construction to minimize bottom disturbance ..................4
Table4. Mitigation summary .........................................................................................................8
List of Appendices
Appendix A: Figures
Figure 1. Project Vicinity
Figure 2. Project Location
Figure 3. Percent Change in Seagrass Cover for Representative Wave Energy Difference of
10% or Greater
Figure 4: Percent Change in Seagrass Cover for Representative Wave Energy Difference of
20°/o or Greater
Figure 5: Project Construction and Staging
Appendix B: Exhibits
Exhibit 1. Reefmaker "Ecosystem" Units Design — Front Elevation View
Exhibit 2. Reefmaker "Ecosystem" Units Design — Profile View
Exhibit 3. Reefmaker "Ecosystem" Units Design — Plan View
i
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
1.0 INTRODUCTION & BACKGROUND
The Herbert C. Bonner Bridge is reaching the end of its service life and needs to be replaced.
The Bonner Bridge provides the only highway connection for Hatteras Island to the mainland in
Dare County, North Carolina via NC 12 and US 64 (Appendix A, Figure 1). The Bonner Bridge
will be replaced with a new bridge that will provide access to Hatteras Island across Oregon Inlet.
The bridge replacement project is known as State Transportation Improvement Project (STIP) B-
2500, replace bridge 270011 (Herbert C. Bonner Bridge) over Oregon Inlet, NC Improvements.
In 2012 CSA Ocean Sciences, Inc. was contracted by the North Carolina Department of
Transportation (NCDOT) to conduct seagrass mitigation to compensate for losses anticipated to
occur during the replacement of the Bonner Bridge over Oregon Inlet (Fonseca, 2015). This
project is part of a larger long-term effort to determine the best strategy and methodology for
seagrass or submerged aquatic vegetation (SAV) restoration and mitigation in North Carolina.
Submerged aquatic vegetation helps stabilize coastal shorelines through rhizome binding of
sediment in shallow nearshore regions, suspended sediment trapping, and wave and current
attenuation. SAV distribution is driven by water depth, light penetration, nutrient loading, salinity,
exposure to waves and currents, biological disturbance and fishing practices, and in particular,
vulnerability to extreme storm events. Because SAV have stabilizing effects on the coastlines
around the areas they inhabit, substantive changes in the SAV community will strongly shape the
physical integrity of the coastline. Also, because SAV provides critically important food and shelter
for fisheries, changes in SAV will affect the fisheries of the future (NCCOS, 2012).
Replacement of the Bonner Bridge will permanently impact approximately 2.66 acres of SAV
areas for which mitigation will be required. Mitigation measures will include removal of the existing
bridge that will unshade 1.38 acres of suitable habitat, and the remaining 1.28 acres will be
mitigated near the project area at the SAV mitigation site described in this plan. This 17-acre
mitigation site will generate 1.3 acres of lift in SAV cover coupled with an additional 0.3 acres of
hard surFace habitat suitable for colonization by algae, oysters and other sessile communities.
1.1 PROJECT OBJECTIVE
The objective of this mitigation project is to reduce the amount of wave energy within the project
site to allow for a more continuous cover of SAV (specifically the seagrasses Halodule wrightii
and Zostera marina) to expand, providing increased seagrass acreage and associated ecosystem
services. These services include water quality improvement, aquatic habitat creation, reduced
sediment movement and plant community establishment. The wave break proposed in this
mitigation plan will also create new linkages between intertidal and aquatic environments.
1.2 EXISTING CONDITIONS
The mitigation site (Site S2) is located immediately west of the existing Bonner Bridge (Appendix
A, Figure 2), and was selected as the preferred site following an April 28, 2015 field verification.
It is located on a stable shoal that has supported patchy seagrass cover since at least 1998.
During the April 28, 2015 field verification, a point-intercept survey was conducted at sites S2,
S2A and S4 to determine the beginning and end point of seagrass along each transect and
ultimately the SAV percent cover. Site S2 demonstrated a modest seasonal fluctuation in
seagrass cover, increasing 15 percent since the previous survey conducted in 2012, but only to
26 percent cumulative cover (Table 1). Site S2A was rejected because of an emerging clay lens
observed in the potential planting area (SAV does not grow well in clay). Site S2 was selected
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
over Site S4 because of the potential for more change in seagrass cover with gap closure among
the existing patches.
iaaie �. sea rass ana eievation surve resuits
Average Patch Seafloor Elevation
Percent Cover Percent Cover Size 2015
Site (2015) (2012) �2 � (ht. above MSL in
(ft ) ft)
Site S2 26 11 26.9 -1.48
Site S2A 3 7 31.2 -2.66
Site S4 54 53 84.6 -2.89
The proposed site will be staked and signed to demarcate the proposed structure location during
the public notice period; additional signage will be posted at Oregon Inlet Fishing Center.
2.0 PROPOSED MITIGATION PLAN
This project is intended for mitigation for SAV impacts associated with Phase I of B-2500, the
Bonner Bridge replacement project. A unique and proven engineered structure is proposed to
attenuate wave energies and provide a suitable wave climate to promote SAV coverage. The
wavebreak will be a permanent, `living' structure.
The proposed structure is a 500-foot long wavebreak. The length was determined by iteratively
adjusting the wall length and running wave and seagrass forecasting models (see below) on each
successive wall length until an increase in seagrass cover meeting the mitigation acreage of 1.28
acres was achieved.
The nearest portion of the structure is approximately 900 feet east of the closest existing tidal
channel and approximately 2,200 feet from the deepest portions of that channel. Given this
distance and the observed stability of the shoal over time (Google Earth imagery; 2004, 2006,
2008, 2009, 2011, 2014 and recent NCDOT high resolution imagery 2012, 2015), this distance is
judged to be adequate to avoid any influence of the channel.
The proposed design involves installing a continuous series of innovative wave attenuation
structures, termed "EcoSystem Units", by Reefmaker (http://www.reefmaker.com/marine-
ecosvstems). Each wave attenuator "unit" is comprised of a stack of concrete molded trays set
with natural rock material such as granite. These systems are designed to fully attenuate wave
energy while still allowing for the exchange of water and the passage of organisms through and
around the structure's individual components. Moreover, they are designed for use in high energy
wave environments and to survive the passage of large storms such as hurricanes. The proposed
structures are comprised of individual units that are four feet tall and approximately five feet wide
(Appendix B, Exhibits 1, 2, and 3). The benefits of this system include its ability to decrease the
wave energy in the target location and to increase hard surface area serving as epibiota habitat
while reducing the benthic footprint compared to other techniques.
2
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
The Reefmaker systems have a much smaller benthic footprint (25 square feet per unit) to reach
the desired height and have less impact upon installation than a traditional rock wavebreak. A
traditional rock wavebreak of similar size with 2:1 slopes would have a 10,000 square foot benthic
footprint. The proposed, 500-foot long Reefmaker structure, is estimated to have a 2,500 square
foot benthic footprint. The design of the Reefmaker "EcoSystem Units" also provides considerable
surface area for oyster settlement and other biofauna (Table 2). Based on preliminary design it is
anticipated that approximately two units will be submerged below the normal high water level.
Table 2. 500-foot Reefmaker structure surface area calculations
Wave Attenuator Surface Areas Total Pilings/Units
Units vertical sq. ft ac
2 11,413 0.26 101
2.5 14,696 0.34 101
3 17,978 (0.41) 101
The design and location of the wavebreak was developed by forecasting the wave conditions
(Malhotra and Fonseca, 2007) and the associated change in seagrass cover that was expected
to occur with the presence of the structure. The relationship of wave energy to predicted percent
seagrass cover of the seafloor (Fonseca and Bell, 1998; re-fit with a yet more conservative
regression model) was utilized to predict the percent seagrass cover of the seafloor with and
without the wavebreak structure present. Change in seagrass cover by creation of the 500-foot
wavebreak was based on the area of wave energy reduction ranging from 10 to 20 percent of
ambient/normal wave energy. This range was judged to provide a conservative estimate of wave
energy reduction over which to forecast seagrass cover while ensuring the target area (1.28
acres) would be met. Figure 3(Appendix A) shows the forecast for wave energy reduction to 10
percent of the ambient/normal wave energy, creating a wave shadow of approximately 57.3 acres.
The forecast increase in seagrass acreage for the 10 percent assessment in this shadow area is
approximately 0.91 acres. Figure 4(Appendix A) shows the forecast for wave energy reduction
to 20 percent of the ambient/normal wave energy, creating a wave shadow of approximately 17.3
acres. The forecast increase in seagrass acreage for the 20 percent assessment in this shadow
area is approximately 1.65 acres. The midpoint of the forecast change in seagrass cover in this
10 to 20 percent range of wave energy reduction is a net addition of 1.3 acres.
Construction of the wavebreak structure will impact some existing seagrass patches. These
seagrass patches will be relocated to gaps among patches on the lee side of the wavebreak
structure to potentially accelerate the anticipated gap closure among the seagrass patches. The
effect of the relocation will be tracked as part of the monitoring survey. Specifically, prior to
installation of the wavebreak, a point-intercept survey will be conducted within the footprint of the
wall and construction access corridor (e.g., construction barge). Three parallel lines running the
entire length of the structure and corridor will be surveyed by this method and the percent cover
of seagrass computed to document the amount of seagrass moved. The performance of the
relocated seagrass will be monitored separately from other surveys, but will employ the same
methods.
In addition, the SAV environment within the vicinity of the existing Bonner Bridge will improve
upon the bridge's removal in that shading to these habitats will be eliminated. The SAV habitat
within the existing bridge location and the area of new bridge construction will be monitored as
outlined in Section 4.0.
3
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
3.0 CONSTRUCTION IMPLEMENTATION AND METHODOLOGY
The construction of the Bonner Bridge seagrass mitigation wavebreak structure involves the
following construction phases:
Phase 1 — Reefmaker Casting
• Setting up the casting molds
• Pouring concrete and creating the Reefmaker units at the land base staging site (Figure
5[Appendix A]) - 301 Harbor Road Wanchese, N.C. 27981)
• Concrete pouring and setting activities will remain in upland staging area
Phase 2 — Material Transport
• Materials including pilings, Reefmakers and hardware will be loaded onto the shallow draft
barges and transferred to the site location from the land based staging area (Table 3)
Table 3. T es of vessels used durin construction to minimize bottom disturbance
Number of
Vessel Each Vessel Size (Ft.) Draft (In.) Specialized Equipment
Type
• 360°sonar
Landing Craft 1 42 X 13 8.0 • Internal Bilge
Barge . Drill Hole
• Liftin Device
Shallow Draft 2 20 X 40 12.0
Barge • Manual Positioning
Shallow Draft 1 24 X 45 12.0 • Customized Mini Excavator
Barge with 42' Extension Arm
Skiff 3 22 X 10 g.p • Custom Jack Plates
• Marine Tug Push Knee
Standard
Jetfloat 1 4 X 4 1.0 — 6.0 • Expandable Units
Platform
Phase 3 — Structure Installation
The 24 X 45 shallow draft barge with a 42-foot custom mini excavator will be used in conjunction
with specialized 8.0-inch spuds to minimize benthic impacts (Photos 1 and 2). A separate
expandable standard jetfloat platform will be erected and attached to the working shallow draft
barge. Pilings will be jetted and vibrated to depths of 20 to 30 feet. The units will be systematically
assembled using the mini excavator 42-foot arm. The Reefmaker unit hardware will be installed
following placement. Due to the dynamics of Oregon Inlet, potential entanglement of aquatic
species and issues concerning worker safety, turbidity curtains will not be used during
construction.
4
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Photo 1. Shallow Draft Barge
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Photo 2. Customized Mini Excavator
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NCDOT will install and maintain any signal lights and signals prescribed by the U.S. Coast Guard,
through regulations or otherwise, on authorized facilities. NCDOT will submit a Private Aids to
Navigation Application to the U.S. Coast Guard. The construction schedule is dependent on
receipt of permits, procurement of contractors, and appropriate weather conditions.
SAV and Benthic Habitat minimization and avoidance measures
During material transport and construction extra caution will be taken not to disturb the bottom
habitat. A specialized landing craft barge will be used during transport and construction phases
to assist with supplies and emergency response (Photo 3). The barge will be equipped with 360°
sonar and an internal bilge system that will be used to monitor water level depths to avoid any
impact to existing SAV during construction.
Photo 3. Landing Craft Barge
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
Threatened and Endanqered Species Protection
During construction all precautions will be taken and activities monitored not to impact Threatened
and Endangered Species. Threatened and Endangered Species Protection measures are
addressed in the original CAMA permit additional conditions sections 35 and 36. These conditions
specify:
35) In accordance with commitments made by the permittee, the discretionary measures
for the piping p�over and three species of sea turtles that are described in the permit
application that include the terms and conditions outlined in the July 10, 2008 United
States Fish and Wildlife Service (USFWS) Biological and Conference Opinions shall be
implemented.
36) In accordance with commitments made by the permittee, all conditions outlined in the
USFWS Guidelines for Avoiding the West Indian Manatee: Precautionary Measures for
Construction Activities in North Carolina Waters shall be implemented.
4.0 MONITORING
Various aspects of the proposed project will be monitored solely for purposes of identifying
contributing factors affecting success of the SAV establishment, coalescence of existing patches,
and overall persistence. These variables will be monitored through statistically robust design and
sampling and documented in order to advance the science and improve the future of SAV
mitigation success in North Carolina.
SAV Mitiqation Site Monitorinq
Mitigation site monitoring will be conducted for up to five years after installation of the wavebreak
structure. The methodology for SAV restoration monitoring includes the following:
o Wave Energy: Pressure sensors will be deployed 25 meters in front of and 25 meters
behind the wavebreak to validate wave simulation models. Sensors are cylindrical
(approximately two inches in diameter by 10 inches long) and will be mounted horizontally
on the seafloor approximately six inches above the substrate on an embedded (into the
seafloor) solid base. These sensors will record wave characteristics. They will be set to
record bursts of pressure data every 30 minutes at a sampling rate of 4 Hz for 128
seconds. These data will also provide water level and tide documentation. During times of
onsite seagrass surveys, these sensors will be systematically but temporarily relocated
across the site to provide a spatially articulated assessment of wave energy distribution
with regard to prevailing conditions. These wave energy maps of the area around each
wavebreak will be used to inform the seagrass survey and determine the onsite
relationships between wave energy distribution and seagrass coverage response.
o Seagrass: Gap closure among seagrass patches and change in seagrass cover will be
evaluated across wave energy regimes (to include at least 57 acres). Four wave energy
regimes (treatments) will be defined by a required re-analysis of the wave energy
distribution of the final wavebreak design and validation. The wave energy regimes will
represent ambient (reference; < 10 percent forecast reduction), low reduction (10 to 33
percent forecast reduction), moderate reduction (34 to 66 percent forecast reduction) and
high wave energy reduction (> 66 percent forecast reduction). The percent reduction
regimes will be defined from a cumulative frequency analysis of the area covered by the
6
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
modeling effort where greater than 10 percent energy reduction was forecast to occur as
the result of the wavebreak structure.
The effect of biological disturbance on seagrass, specifically gap closure will also be
tested. Two bioturbation exclusion treatments will be utilized, one with and one without
exclusionary wire mesh (removed after patch coalescence has occurred). Large gap (four
to six inch) metal mesh will be laid flush on the seafioor and anchored with approximately
one to two-foot long J-shaped rebar stakes. Seagrass shoots would extend through the
large gaps allowing their continued growth and expansion (vis a vis "TERF" method
http://seaqrant.mit.edu/eelgrass/backqround/transplantinq.html; F. Short, UNH). Flush
deployment on the seafloor plus anchoring is performed to prevent entanglement by sea
life, such as diving birds.
Randomly selected seagrass patches will constitute the individual (replicate) test units. To
choose individual test units, a location will be randomly chosen in each forecast wave
energy treatment area. The nearest seagrass patch to that location meeting two criteria
will be selected as a test unit. The individual seagrass patch must first approximately
match the average site patch size (+/- 1 standard deviation). The seagrass patch must
also be separated from the next nearest patch by a minimum of the site average gap
distance. Ten patches will be selected per wave energy treatment; five will be protected
with wire mesh and five will be un-protected. The statistical approach for this experiment
on the effect of waves and biological disturbance on patch expansion is a repeated
measures two-way analysis of variance with wave energy and patch protection as main
effects. The survey will end when patch coalescence begins; at this point the mesh and
stakes will be removed and disposed of appropriately.
o Structure/Hard Surface: Epibiota on the structure will be monitored through the
establishment of randomly-placed, permanent quadrats, stratified by either side of the
wavebreak (exposed versus sheltered side) and by elevation on the structure (near
seafloor, mid-tide, high-tide) for a total of six monitoring strata. Ten quadrats would be
assigned per strata for a total of 60 quadrats. Epibiotic coverage will be evaluated annually
using a repeated measures design. The quantification will be determined based on the
epibiota that recruit, but is anticipated to include percent cover by community type visually
identified to the lowest practicable taxonomy.
o Sediment Elevation: Digital elevation models will be created encompassing the full
forecast extent of wave attenuation out to and including adjacent reference areas un-
affected by the wavebreak to relate seagrass response not only to changes in wave
climate but also to quantify any changes in sediment elevation. Sediment accumulation or
loss can strongly affect seagrass coverage and thus is needed to provide explanatory
capacity for seagrass performance. Because the wavebreak structure will be installed on
a flat sand surface, little change in seafloor elevation is anticipated around the structure
as the result of changes in wave energy. Wave refraction should be limited (i.e., no change
in seafloor elevations) and effects should be limited primarily to wave diffraction. Any
changes arising from the structure are anticipated to be minor and immediately adjacent
to the wavebreak itself. The wavebreak is also installed at the seafloor surFace to prevent
sand scour under the structure.
The information obtained through the monitoring of this project will substantially increase the state
of seagrass mitigation science by both quantifying the relationship between seagrass cover and
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
wave energy and by understanding the difference in the expansion rate of patches among
armored and unarmored patches. Improving the quantification of wave and seagrass landscape
cover will specifically inform future seagrass mitigation efforts using wave attenuation
approaches. Similarly, understanding the relative impact of bioturbation versus waves on
maintenance of seagrass landscapes will inform future mitigation efforts as to the degree (if any)
of bioturbation exclusion needed to effect persistent coverage. Both aspects (waves and
bioturbation) address important information gaps for North Carolina (and elsewhere) regarding
the relative influence of waves and bioturbation on seagrass patchiness and have high intrinsic
value.
Temporary SAV Impact Monitorinq
NCDOT will provide an annual update on the SAV areas temporarily impacted by the bridge
construction. This annual update will consist of photographs and a written report on the progress
of the temporarily impacted areas in re-attaining their pre-project abundance. Within three years
after project completion, NCDOT will hold an agency field meeting with DCM to assess if the SAV
areas temporarily impacted by this project have re-attained pre-project abundance (distribution or
coverage).
Existinq Bridge SAV Habitat Monitorinq
In addition to the proposed mitigation site, the aquatic area in the vicinity of the existing Bonner
Bridge will be monitored upon removal of the bridge to assess whether and/or to what extent the
effects of removing shade will be to SAV and their habitat.
5.0 REMEDIATION AND LONG-TERM MANAGEMENT
The wavebreak will be inspected for damage annually during the five year monitoring period. If
monitoring data indicate that damage to the structure is having a negative effect on SAV coverage,
then a remediation plan will be developed in coordination with DCM. In addition, the annual
inspection will verify that the required signage and markings are present and visible.
6.0 MITIGATION SUMMARY
The implementation of this plan is proposed as mitigation for approximately 2.66 acres of impact
from the B-2500 Bonner Bridge replacement project to existing SAV by creating and affecting the
local marine environment in the vicinity of the bridge, as an attempt to make it more conducive to
the establishment and enhancement of SAV. Table 4 includes a summary of the proposed
mitigation and the estimated acreages of each component.
Table 4. Miti
Unshaded Area
From Existing
Bridge (ac)
1.38
summary
SAV Increase
(Uplift) Due to
Wave Attenuation
of
10 to 20% ac
0.91 - 1.65
Hard Surface
Habitat Area
(sq. ft (ac))
11,413 (0.3
Wavebreak
Shadow (ac)
17 to 57
Increase in
Seagrass
(lift in ac)
1.3
8
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STIP 8-2500 Bonner Bridge Phase 1 SAV Mitigation Plan
7.0 REFERENCES
Fonseca, Mark and Susan S. Bell. 1998. "Influence of Physical Setting on Seagrass Landscapes
near Beaufort, North Carolina, USA." Marine Ecology-Progress Series. 171: 109-121.
Fonseca. 2015. Memo on 9 June, 2015 from Mark Fonseca to Kathy Herring at NCDOT RE:
Bonner Bridge Seagrass Mitigation Project (State Project 32635.1.3; TIP B-2500) Task B(Site
Verification) Letter Report.
Google Earth Imagery, 2004, 2006, 2008, 2009, 2011, 2014
Malhotra, A. and M.S. Fonseca. 2007. WEMo (Wave Exposure Model): Formulation, Procedures
and Validation. NOAA Technical Memorandum NOS NCCOS #65. 28 pp.
http://www.ccfhr.noaa.qov/docs/NOS NCCOS 65.pdf
NCCOS. 2012. Habitats of coastal North Carolina.
NCDOT. 2012. High Resolution Aerial Photography.
NCDOT. 2015. High Resolution Aerial Photography.
NCDWQ 401 Water Quality Certification Pursuant to Section 401 of the Federal Clean Water Act
with ADDITIONAL CONDITIONS for the Proposed Replacement of the Herbert C. Bonner Bridge
over Oregon Inlet in Dare County, Federal Aid Project No. BRNHF-0012(48), TIP B-2500 (Phase
I). NCDWQ Project No. 20120629. September 7, 2012.
9
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Appendices
Appendix A: Figures
Figure 1. Project Vicinity
Figure 2. Project Location
Figure 3. Percent Change in Seagrass Cover for Representative Wave Energy
Difference of 10% or Greater
Figure 4: Percent Change in Seagrass Cover for Representative Wave Energy
Difference of 20% or Greater
Figure 5: Project Construction and Staging
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Figure 1:
Project Vicinity
STIP B-2500 BONNER BRIDGE
SAV MITIGATION PLAN
DARE COUNTY - NORTH CAROLINA
SEPTEMBER 2015
Source: Bing Maps
Figure Date: 05/06/2015
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This Exhibit is for planning purposes only and shown herein does not meet NC 47-30 1 inch - 4,000 feet
Requirements and therefore is not for design, construction, or recording or transfer of Figure 2: Project Location �
title. The Exhibit was compiled from available information obtained from the sources ����
�isted be�ow. GRAPHIC SCALE
STIP B-2500 BONNER BRIDGE
Sources: 0 2,000 4,00o s,000 SAV MITIGATION PLAN � E� � ��� E R � N ��
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Wave Energy Difference of 10% or Greater
STIP B-2500 BONNER BRIDGE
SAV MITIGATION PLAN
1 inch = 390 feet 0 195 390 780
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STIP B-2500 BONNER BRIDGE
SAV MITIGATION PLAN
1 inch = 325 feet 0 162.5 325
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This Exhibit is for planning purposes only and shown herein does not meet NC 47-30 1 inch = 4 000 feet Figure 5: Project Construction and Staging
Requirements and therefore is not for design, construction, or recording or transfer of � � ����
title. The Exhibit was compiled from available information obtained from the sources
�isted be�ow. GRAPHIC SCALE
STIP B-2500 BONNER BRIDGE
Sources: 0 2,000 4,000 8,000 �
EHGI N!EERI NG G
Aerial and Topographic Mapping SAV MITIGATION PLAN C 4 N 5 T R U C T I 0 M
Feet
Appendix B: Exhibits
Exhibit 1. Reefmaker "Ecosystem" Units Design — Front Elevation View
Exhibit 2. Reefmaker "Ecosystem" Units Design — Profile View
Exhibit 3. Reefmaker "Ecosystem" Units Design — Plan View
Exhibit 1. Reefmaker "Ecosytem" Units Design - Front Elevation View
NAVIGAT'^n i n i
M UST
WAV E ATl
PYLON WI
FRONT ELEVATION VIEW
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)SITE
E�ibit 2. Reefmaker "Ecosystem" Units Design - Profile View
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E�ibit 3. Reefmaker "Ecosystem" Units Design - Plan View
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