HomeMy WebLinkAboutAppendix A supp. Equilibration profilesConstruction Templates Equilibration
To quantify the equilibration, the construction template at three representative locations within
the project area were chosen and run in SBEACH. This analysis was only performed at
construction templates with a dune and sloped berm to analyze the impact to the recreational
beach width during equilibration. Construction templates consisting of a dune and berm
combination or berm only were not analyzed. The assumption was made that the recreational
beach width would not be significantly impacted in these construction templates during
equilibration. The output profile from the 2-yr storm was used as an assumption of the resulting
equilibrated construction template. Results are shown in Figure 2-13 through Figure 2-15, the
preconstruction profiles shown in the figure are from the June 2019 survey. The model indicates
that material placed in the dune and sloped berm will be transported to the offshore bar. Mild
equilibration of the dune profile is also expected; however, this will act as a sand source for the
sloped berm over time. The equilibrated construction template will maintain a similar
recreational beach width when compared to the 2016 (Pre -Matthew) conditions when a dune
was present within the project area.
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Figure 2-13. Station 540+00 Equilibrated Construction Template
NCDCM Major Permit Modification #31-20
2021/2022 Oak Island Renourishment Project
Moffatt & Nichol
October 2020
23
Figure 2-14. Station 570+00 Equilibrated Construction Template
18
16
14
12
00 10
0 8
6
z 4
2
0 0
> -2
a�
w -4
-6
-8
-10
-12
600+00 Equilibration Profile
0 100 200 300 400 500 600 700 800
Distance from Baseline (ft)
Preconstruction------- Construction Template Equilibration
Structure Location Pre Matthew 2016
Figure 2-15. Station 600+00 Equilibrated Construction Template
NCDCM Major Permit Modification #31-20
2021/2022 Oak Island Renourishment Project
Moffatt & Nichol
October 2020
24