HomeMy WebLinkAbout20020730 Ver 4_More Info Received_202307274700 Falls of Neuse Road, Suite 300 ,,,,
Raleigh, North Carolina 27609
moffafi & niahol (919)781-4626
www. rnoffattnichol. corn
July 26, 2023
US Army Corps of Engineers
Wilmington District
69 Darlington Avenue
Wilmington, NC 28403
Attn: Greg Currey / Regulatory Project Manager
Subject: Response to Comment Letter #2 for USS Battleship North Carolina - Living with Water
Improvements, State ID#: 20-21601-02A/SAW 2010-00175
Dear Mr. Currey,
Thank you for your time and effort in reviewing our permit application for the USS Battleship North Carolina
Living with Water Improvements Project. Below are the responses to your comments dated July 12, 2023:
1) Alternatives Analysis
RESPONSE:
Project Purpose and Need
The North Carolina Department of Natural and Cultural Resources seeks to mitigate flood risk, preserve access
to the USS Battleship North Carolina, a World War 2 Memorial and National Historic Landmark, and restore
the local estuarine ecosystem.
No Build Alternative
The Battleship is berthed on the Cape Fear River approximately 28 miles upstream of the river's confluence
with the Atlantic Ocean. Resting on the west bank of the river directly across from downtown Wilmington, it
is surrounded by 65-acres of State-owned property on Eagles Island.
While much of Wilmington lies on relatively higher ground, Eagles Island mostly is low-lying, brackish,
marshland. These marshes are ecologically significant coastal habitats for plant communities, wildlife,
anadromous fish, and environmental functions/services including water quality, carbon sequestration, and
resiliency hubs.
The Battleship also rests approximately 850 meters upstream of the Cape Fear Memorial Bridge. At the foot
of the bridge is the NOAA Tidal Gauge (Station 8658120). Established in 1908, the gauge documents the
longest tidal record in the region. The tide in this portion of the Cape Fear River fluctuates daily by 4 to 5 feet.
The western edge of the Battleship parking lot is below Mean Higher High Water and the highest ground in
the parking lot is only a few feet above sea level. Rising seas have increased the frequency and severity of tidal
flooding.
The Battleship has witnessed a 7,021% increase in tidal flooding since arriving in North Carolina in 1961 with
a significant uptick in the 1990s and unprecedented flooding from 2010 to 2020. Tidal data between 2011 -
2020 reveals a 770% increase in tidal flooding over the decade. By 2020, the Battleship property was flooded
nearly half of the year. Additionally, the highest tide ever recorded at Station 8658120 occurred during
Hurricane Isaias on August 4, 2020.
,A,q Page 1
By law, the Battleship receives no financial support from tax revenues and must rely on visitor receipts (ticket
admissions, gift shop sales, programs, events, and rentals) to pay salaries, operations, and regular maintenance.
High tides render much of the parking lot unusable and force visitors to wade through water to reach the
Visitor Center entrance. Flooding interrupts visitation creating safety and operational hazards and degrades
water quality and natural habitats. If flooding continues to impact the number of patrons visiting the site, then
the Battleship will be in financial jeopardy.
Preferred Alternative
The Battleship has been evaluating alternatives to mitigating flooding since 2015 with the initiation of a US
Army Corps of Engineers (USACE) Special Investigations study to analyse hydrology and hydraulics on the
Battleship site (previously provided as Attachment B). Based on the USACE's analysis and findings, three
alternatives were identified and included storm drainage improvements, increase land elevation, and a levee or
flood wall system. The preferred alternative from the USACE Study is Alternative 2 — Increase Land Elevation. This
alternative is encompassed in the overall design of the "Living with Water" plan, which was modelled after the
Dutch approach of integrated water management and flood infrastructure planning with multi -benefit
investments. The parking lot will be raised above the more frequent flood elevation using fill material. Raising
the elevation of the parking to 6.0 ft NAVD88 will provide additional protection.
The design team identified additional project elements that were necessary to reduce the Battleship's risk from
nuisance flooding and coastal inundation, as proven by recent data to be increasing. The "Living with Water"
project incorporates three major strategies for developing a long-term resiliency plan: coastal defense; "Living
with Water" strategy; and connectivity to historical, cultural, and environmental amenities. Finding or creating
space for water to provide opportunities for increased water storage, habitat regeneration, and recreation were
the guiding principle used throughout project planning and design.
The proposed "Living with Water" project provides a sustainable design to address water quality impairments
in the lower coastal Cape Fear River watershed. Our team's approach aims to mimic the natural, pre -
development hydrology of Eagles Island by reducing runoff and nuisance flooding and help to restore water
quality requirements of the receiving surface water. By reducing the existing parking lot area, non -point source
discharges will be reduced from vehicles, buses, and operation/maintenance equipment. In addition to creating
Primary Nursery Area habitat for forage fish and shrimp, the approximately 8001.f. of restored living shoreline
will provide an effective and sustainable method to managing the shoreline within the Battleship's berth.
Living Shoreline Alternative
The southern shoreline of the Battleship's berth has
been heavily modified over the years and is currently
covered in loose rubble and concrete roadway slabs
and/or barriers to protect against erosion. Design
alternatives included a rock sill that would serve as the
foundation to regrade the shoreline to create the
intertidal regime that will sustain plants and marsh
grasses in this environment. The team revisited the
use of rock sill, evaluating its performance to
maintain the desired shoreline slope and intertidal
regime, and ability to minimize wave action and
siltation rates that could affect the long-term
sustainability of the intertidal habitats.
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The preferred alternative for the living shoreline includes
removing existing rock material and regrading of the bank only
to create a natural shoreline with native marsh plantings.
,A,q
Page 2
2) Update wetland creation acreage.
The boardwalk across the created tidal creek and wetlands cannot be adjusted due to ADA compliance and will
be required for full access to the tidal creek. The elevation of the boardwalk was designed to tie-in to sidewalk
and cannot be adjusted. The tidal creek and associated wetland habitat shaded by the boardwalk is 0.08 acres
and can be removed from the wetland creation total (1.33 acres). The corrected total of wetlands created will
be 1.25 acres.
Table 1: Sumnary of metland impacts and proposed enhancements
Type of Wetland Impact Acreage I S . ft. Description
Permanent
MP-2 (4b)
Fill
0.26
11,326
Fill of existing coastal wetlands
MP-2 (1 c)
Coastal wetland excavation
Excavation
0.74
32,235
(existing wetland to enhanced
wetland
MP-2(lc)
Excavation
0.08
3,485
Existing wetland conversion to
constructed tidal creek channel
Total
1.08
47,046
Temporary
Temporary
0.43
18,731
Temporary coastal wetland
impacts in DOT right-of-way
Total
0.43
18,731
Creation
Tidal wetland
1.15
50,094
Tidal wetland created
Tidal creek
0.10
4,356
Tidal creek created
Total
1.25
54,450
Note: Bold numbers represent the removal of 0.08 acres of shaded impact from boardwalk to created
wetlands.
3) Purpose and Need of the Living Shoreline portion of the Project.
The purpose and need of the living shoreline are to naturally stabilize the shoreline along the Battleship berth.
A living shoreline was selected as the preferred method of stabilization because it provides wetland habitat and
pollutant removal.
4) You state in the application narrative "The wetland and tidal creek will capture, hold, infiltrate,
and direct tidal floodwaters to the Cape Fear River." Can you expand on this, describing the
flooding reduction mechanisms or processes? Also expand here describing what conditions of
the current site facilitate or cause flooding.
RESPONSE:
The main parking lot will be graded to drain to a central stormwater wetland for detention and treatment of
runoff. Discharge from the wetland is directed to a tidal creek that is graded to drain to the ship berth area and
the river. During higher flows or river levels, the runoff flow will be spread into the tidal wetland area where
some treatment will occur. When the river level lowers, the tidal wetland will be graded to the living shoreline
or tidal creek such that the wetland does not hold surface water.
,A„ Page 3
5) Installation of Water Level Sensors
The Battleship has committed to a Memorandum of Agreement with the NOAA National Ocean Service in
Beaufort to provide for long term physical monitoring of the site post -construction. The installation of water
level sensors on site was done between August 2018 and January 2019 to develop an understanding of tidal
inundation associated with rainfall and tidal events within the project area. It is anticipated these same sensors
(HOBO pressure sensors) can be installed within the requested wetland creation areas to monitor continuous
water level data.
6) Provide a Monitoring and Maintenance Plan.
An updated monitoring plan is provided as an attachment to this letter. Recommended metrics, success criteria
and adaptive management measures have been included.
If you have any questions or concerns, please feel free to contact me anytime at dyork@moffattnichol.com.
Sincerely,
Dawn York 1
Senior Coastal Planner
238 Princess St. Wilmington, NC 28401
P 910.218.7087 M 910.612.1152
moffatt & nichol
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USS BATTLESHIP NORTH CAROLINA
LIVING WITH WATER IMPROVEMENTS
WILMINGTON, NORTH CAROLINA
MONITORING PLAN
SCO ID NO. 20-21601-02A
July 2023
Prepared For:
USS BATTLESHIP NORTH CAROLINA
1 BATTLESHIP ROAD
WILMINGTON, NORTH CAROLINA 28401
BATTLESHIP ' MEN
.-U.i s
CULTURAL
RESOURCES
NORTH CAROLINA
Submitted By:
moffatt & nichn
4700 Falls of Neuse Road, Suite 300
Raleigh, North Carolina 27609
919-781-4626
M&N Project No. 10258-02
USS Battleship North Carolina: Living with Water Improvements
Monitoring Plan
Table of Contents
1. Introduction.............................................................................................................................................................................. iii
1.1. Project Area Wetlands Description............................................................................................................................................iii
1.2. Proposed Wetland Impacts........................................................................................................................................................ ii
2. Monitoring Plan........................................................................................................................................................................ni
3. Success Criteria.......................................................................................................................................................................iv
3.1. Wetland Vegetative Cover......................................................................................................................................................... iv
3.2. Wetland Hydrology (Tidal Events)............................................................................................................................................ iv
3.3. Tidal Creek................................................................................................................................................................................. iv
4. Adaptive Management Plan...................................................................................................................................................iv
List of Figures
Figure 1: Preliminary jurisdictional determination.................................................................................................................................. ii
List of Tables
Table 1: Summary of wetland impacts and proposed enhancements..................................................................................................iii
Table 2: Post project monitoring for living shoreline and wetland creation and enhancement............................................................iii
,1„ 2
LISS Battleship North Carolina: Living with Water Improvements
Monitoring Plan
1. Introduction
The Battleship is under threat from storm surge, sea level rise, sunny day tidal flooding and stormwater
run-off. Notwithstanding hurricanes, the Battleship has seen more flood stage events in the past decade
than in the previous 60 years. Resting 28 miles upstream of the Atlantic Ocean, the Battleship property is
hydrologically contiguous to more than 2000 acres of tidal wetlands and intertidal shoreline on Eagles
Island. Like many coastal sites, an increasing trend in tidal flooding causes problems. Tidal erosion and
flooding inundation damages habitats, creates sink holes, reduces accessibility to the Memorial, and
degrades water quality with vehicular pollutants, soil, and silt. The Battleship is committed to an on -the -
ground green infrastructure solution to improve accessibility, prepare for, and adapt to climate change, and
improve degraded fish and wildlife wetland habitats and water quality.
The Living with Water Project is designed to reduce flooding occurrences to ensure the public has safe
access to visit the Memorial, as well as support water quality and natural habitat improvements. The Living
with Water Project uses nature -based infrastructure to capture, hold, infiltrate, and direct floodwaters to the
Cape Fear River. A naturally enhanced shoreline constructed tidal marsh and creek, and parking lot
improvements will work in tandem to mitigate flood risk, improve water quality, and provide ecosystem and
educational benefits.
1.1. Project Area Wetlands Description
The project area encompasses approximately 1.5 acres of brackish and freshwater marshes on the
contiguous tidal floodplain of the Cape Fear River (Figure 1). Brackish tidal coastal marsh forms a
continuous fringe along the project area shoreline that is interrupted by extensive rip rap within the berth.
The landward boundary of the tidal wetlands within the project area is bounded by USS North Carolina
Road. The road functions as an artificial berm that has effectively expanded tidal influence into the
Battleship's western parking area allowing for disturbed brackish marsh dominated by narrow -leaved cattail
(Typha angustifolia) and large dense monospecific stands of common reed (Phragmites australis). A
preliminary jurisdiction wetland determination was completed in May 2021 and submitted to the Corps of
Engineers and a subsequent site visit was conducted in which wetland line was concurred.
USS Battleship North Carolina: Living with Water Improvements
Monitoring Plan
MOFFATT AND NICHOL PERFORMED A WETLANDISTREAM DETERMINATION ON 25 MAY, 2021. MOFFATT AND NICHOL FINDINGS
HAVE NOT BEEN SURVEYED OR VERIFIED BY THE USACE OR NCDWR. THIS EXHIBIT SHOULD BE USED FOR PRELIMINARY
Moffatt & nichoi PLANNING PURPOSES MOFFATT AND NICHOL RECOMMENDS CONSULTATION WITH A CIVIL ENGINEER TO CONFIRM THE LOCAL
BUFFER REQUIREMENTS- THIS IS NOTA SURVEY NOR SHOULD BE TREATED AS SUCH.
Wetland reas (Acres)
1. BATTLESHIP WA: 0.216A
VVB. 1.217
NORTH CAROLINA WC: 0.120
Battleship NO
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Wilmington, NC 28401
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FIGURE 1
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Figure 9: Preliminary jurisdictional determination
1.2. Proposed Wetland Impacts
Legend
[:]Wetland Study Areas
MWetlands
111 Concrete Wall Barrier
The Living with Water Project comprises three components, including 1) Living Shoreline, 2) Tidal Creek
and Wetland, and 3) Green Infrastructure Improvements. The living shoreline activity will restore more than
720 linear feet of hardened shoreline that had been stabilized over decades with layers of riprap materials
to a natural intertidal estuarine shoreline using a nature -based design.
Proposed tidal creek and wetland activities will create 1.3 acres of new coastal wetlands, enhance 0.74
acres of existing coastal wetlands through excavation to a lower elevation to capture tidal floodwaters and
establish native species, and convert 0.08 acres of existing coastal wetland to open tidal creek channel.
The impervious, flood -prone area of existing visitor parking and disturbed wetlands will be converted to
intertidal wetland habitat with a tiered elevation design to support habitat migration and allow for adaptation
of coastal wetland native plant species. There is a net decrease in impervious area (approximately 0.5
acres) based on removal of the existing deteriorated parking lot.
Based on a site visit by Division of Coastal Management staff in June, it was determined that the existing
wetlands within the project site are designated as coastal due to tidal influence from receiving waters and
presence of coastal wetland species. As listed in Table 2.1 and shown in Figure 2.1 below, a breakdown of
wetland impacts are as follows:
111111111110
USS Battleship North Carolina: Living with Water Improvements
Monitoring Plan
Table 1: Summary of wetland impacts and proposed enhancements
T e of Wetland Im act
Acreage S . ft.
Descri d
1111111100—
Permanent
MP-2 (4b)
Fill
0.26 11,326
Fill of existing coastal wetlands
MP-2 (1 c)
Coastal wetland excavation
Excavation
0.74
32,235
(existing wetland to enhanced
wetland
MP-2 (1 c)
Excavation
0.08
3,485
Existing wetland conversion to
constructed tidal creek channel
Total
1.08
47,046
Temporary
Temporary
0.43
18,731
Temporary coastal wetland
impacts in DOT right-of-way
Total
0.43
18,731
Creation
Tidal wetland
1.15
50,094
Tidal wetland created
Tidal creek
0.10
4,356
Tidal creek created
Total
1.25
54,450
2. Monitoring Plan
Post -project monitoring will be used to determine the success of the project's goals — restoration of an
intertidal estuarine shoreline and creation of subtidal and intertidal wetland habitat. The below table shows
post -project monitoring procedures, metrics that will be collected and the frequency of data collection. The
spatial extent of post -project monitoring is the activity footprint of the restored living shoreline and
established tidal wetland.
Table 2: Post pr ject monitoring for living shoreline and wetland creation and enhancement
Metrics nits
Methods
Frequency and Timing
Percent Cover of Vegetation (0-
Percent Cover of Vegetation by
Once per year for 3 years post-
100%)
species including Phragmites
construction
Elevation (feet)
Various elevation measurements
Once per year for 3 years post -
throughout Project Footprint
construction
Wetlands Hydrology Elevation
Measurements of water level in
Daily Measurements using an
feet
Low Marsh and in High Marsh
accepted water level sensor
Tidal Creek and Living Shoreline
Visual Monitoring and
Once per year for 3 years post -
Areas
Photographs
construction
USS Battleship North Carolina: Living with Water Improvements
Monitoring Plan
In addition to the post -project monitoring procedures in the above table, implementation monitoring will
evaluate the extent to which the final mature site mirrors the planned design and includes the following
protocols:
Preparation of an as -built elevation survey of the entire project area after construction to verify
planned target elevations and to provide a baseline against which to measure future changes
during the monitoring period.
2. A stratified random design will be used to determine the placement of individual sampling plots
along each transect.
3. Plots will be visited and evaluated annually during the period of peak biomass (late July to early
August) for species composition and percent cover.
3. Success Criteria
3.1. Wetland Vegetative Cover
Year 1: No more than 10% mortality of planted stems and less than 5% cover of Phragmites.
Year 2: No more than 10% mortality of planted stems and less than 5% cover of Phragmites. In combination
with the planted stems and volunteers of the same species, the low and high marsh areas must exhibit an
overall 50 % ground cover.
Year 3: No more than 10% mortality of planted stems and less than 5% cover of Phragmites. In combination
with the planted stems and volunteers of the same species, the low and high marsh areas must exhibit an
overall 85% ground cover.
All volunteer species must be noted separately and may be deemed suitable toward meeting the success
criteria.
3.2. Wetland Hydrology (Tidal Events)
For Low Marsh Areas (S. altem flora): Area must exhibit normal diurnal tide cycle events.
For High Marsh Areas: Area must exhibit normal irregular tide events, a minimum of 3 times a year.
3.3. Tidal Creek
Tidal Creek must be stable and not show signs of significant erosion, such as headcutting or eroding banks.
The monitoring period will be for 3 years, or until deemed successful if corrective measures have to be
initiated due to failure of any of the above success criteria.
4. Adaptive Management Plan
For the created/enhanced tidal creek wetland areas: If area fails to meet the yearly vegetation success
criteria, corrective measures may be implemented. These measures may include supplemental plantings
or removal of unsuitable species through herbicidal application or by hand. If the area fails to meet the
yearly hydrology performance standard, regrading may be implemented. Other adaptive measures may be
deemed necessary contingent on the circumstances.