HomeMy WebLinkAboutAppendix J -Supplemental ProfilesAPPENDIX J
SUPPLEMENTAL PROFILES
These supplemental profiles are being provided at the request of NCDCM. These profiles
demonstrate how the location of the construction template dune is consistent with the historical
dune location. With the absence of existing vegetation, it may be desirable to move the dune
alignment further landward. However, a more landward dune alignment also moves the MHW
contour closer to structures and affects the vegetation line setback used for development
purposes. The location and alignment of the construction template is based on historical profiles
and construction feasibility. It is important to the Town to maintain a historic dune and
vegetation alignment which existed prior to Hurricane Matthew (2016).
The construction template dunes will appear taller and wider than what has existed historically
as the construction template dune has been engineered to withstand a 25-year return period
storm event. The design intent is to provide the shoreline with protection from future storms and
ensure that this level of protection is continually maintained as part of the Master Plan.
These permit drawings are not intended to be used for construction but represent the general
design template. The Town has conducted an emergency dune push across the project area since
the existing ground survey, and therefore the elevations on the permit drawings have changed.
The Town is also proceeding with placement of overwash sand within the project area. The
landward tie in shown on the permit drawings will evolve based on the interim placement
activities and other natural recovery that will take place prior to construction start. The seaward
tie in is also expected to change based on how the wave climate influences the offshore
environment. Specific design template elements that will not change include increased project
extents (project extents may decrease), the dune height, width, and slopes, the
alignment/location of the dune, and berm widths where applicable.
Construction drawings will be developed based on transects every 100 feet that will be collected
six weeks prior to construction. The construction drawings will reflect actual existing conditions
prior to construction and will also include vehicle and pedestrian beach accesses. The design
template will be modified to prevent trenches at the landward tie in location where turtles or
their hatchling may be trapped behind the dune.
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-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
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f
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A
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8
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Distance from Baseline (ft)
Monitoring Sta 210+00 (Project Sta 210+00)
Structure 2014 2015 2016 Post Matthew
2017 2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-12
-10
-8
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-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
v
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i
o
n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoring Sta 220+00 (Project Sta 219+54)
Structure 2016 Post Matthew 2017
2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-14
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-10
-8
-6
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0
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8
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-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
v
a
t
i
o
n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoring Sta 230+00 (Project Sta 229+38)
Structure 2014 2015 2016 Post Matthew
2017 2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-16
-14
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-8
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2
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-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
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t
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n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoring Sta 510+00 (Project Sta 508+50)
Structure 2016 Post Matthew 2017
2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-16
-14
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-8
-6
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0
2
4
6
8
10
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-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
v
a
t
i
o
n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoring Sta 540+00 (Project 537+70)
Structure 2014 2015 2016 Post Matthew
2017 2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
14
16
18
20
-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
v
a
t
i
o
n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoring Sta 570+00 (Project Sta 567+56)
Structure 2016 Post Matthew 2017
2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-8
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0
2
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6
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-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
v
a
t
i
o
n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoringn Sta 600+00 (Project Sta 597+56)
Structure 2014 2015 2016 Post Matthew
2017 2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template
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-10
-8
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0
2
4
6
8
10
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20
-100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
El
e
v
a
t
i
o
n
(
f
t
,
N
A
V
D
8
8
)
Distance from Baseline (ft)
Monitoring Sta 620+00 (Project Sta 617+53)
Structure 2014 2015 2016 Post Matthew
2017 2018 Post Florence 2019 Post Dorian
2020 Post Isaias Construction Template