Bogue Banks Beach - Carteret County Shore Protection Office

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Final Report Bogue Banks Beach & Nearshore Mapping Program Periodic Survey Evaluation Accretion Erosion Volume Change (cy/ft) 40 30 20 10 0 -10 -20 -30 -40 5.4.4. Atlantic Beach Pine Knoll Shores Unit Volume Change West East 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 Transect Number Volume Change Above MHW Volume Change Above -5 ft Volume Change Above -12 ft Volume Change Above -20 ft Volume Change Above -30 ft Figure 12. Pine Knoll Shores Unit Volume Change (2010 - 2011) The Atlantic Beach region covers Transects 77 through 102. Since monitoring began in 1999, the region has received 3.72 million cy of nourishment material from the Brandt Island Pump Out and USACE dredge disposal. Most recently, approximately 800,000 cy of material was placed on Atlantic Beach as Year 1 of the USACE Interim Operation Plan for the Morehead City Harbor Federal Navigation Project. A summary of average shoreline and volume changes between 2010 and 2011 for the Atlantic Beach region are presented in Table 18. Table 18. Average Shoreline and Volume Change for Atlantic Beach Reach Length Pine Knoll Shores West avg shoreline change @ MHW avg volume change above +1.1 ft NAVD cumulative volume change above +1.1 ft NAVD avg volume change above -5 ft NAVD cumulative volume change above -5 ft Pine Knoll Shores East Atlantic Beach saw a large amount of shoreline accretion and volume gain due to the recent nourishment project. In the area that was nourished (Transects 90-102), the volume change above -12 ft NAVD88 was approximately 799,100 cy, indicating that nearly all of the nourishment material (799,504 cy) has remained in place since they finished nourishing in April 2011. The volume change above -12 ft NAVD88 for all of Atlantic Beach is approximately 750,500 cy, indicating some minor losses to the unnourished portion of the beach. It is likely that the minor loss of material along the western portion of Atlantic Beach has been transported November 2011 26 NAVD avg volume change above -12 ft NAVD cumulative volume change above -12 ft NAVD avg volume change above -20 ft NAVD cumulative volume change above -20 ft NAVD avg volume change above -30 ft NAVD cumulative volume change above -30 ft NAVD Reach (Profiles) ft ft cy/ft cy cy/ft cy cy/ft cy cy/ft cy cy/ft cy Atlantic Beach (77-102) 26,176 53.2 12.8 333,780 28.1 735,811 28.7 750,462 22.3 584,654 19.5 511,064
Final Report Bogue Banks Beach & Nearshore Mapping Program Periodic Survey Evaluation east to the nourished portion of the beach. Figure 13 displays the unit volume change for each transect in the Atlantic Beach region. While the nourishment is very noticeable at the eastern end of Atlantic Beach, the western end of the reach did show some slight losses. It is also interesting to note that the small changes at Transects 94 and 95 line up with the location at the Oceanana pier where material has historically not been placed. Accretion Erosion Volume Change (cy/ft) 150 130 110 90 70 50 30 10 -10 -30 -50 Atlantic Beach Unit Volume Change West East 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 Transect Number Volume Change Above MHW Volume Change Above -5 ft Volume Change Above -12 ft Volume Change Above -20 ft Volume Change Above -30 ft Figure 13. Atlantic Beach Unit Volume Change (2010 - 2011) 5.4.5. Fort Macon State Park The Fort Macon State Park region covers Transects 103 through 112. Since monitoring began in 1999, this region has received 1.27 million cy of nourishment material from USACE Inner Harbor Dredging Disposal. Most recently, 547,000 cy of material was placed on Fort Macon from November 2010 to April 2011 as part of the Year 1 USACE Interim Operation Plan for the Morehead City Harbor Federal Navigation Project. A summary of average shoreline and volume changes between 2010 and 2011 for the Fort Macon State Park region are presented in Table 19. Table 19. Average Shoreline and Volume Change for Fort Macon State Park Reach Length avg shoreline change @ MHW avg volume change above +1.1 ft NAVD cumulative volume change above +1.1 ft NAVD avg volume change above -5 ft NAVD cumulative volume change above -5 ft Fort Macon saw a large amount of shoreline accretion and volume gains due to the nourishment project. It appears that much of the nourishment has remained in place so far given a volumetric change of 596,000 cy above -12 ft NAVD88. This indicates that likely some sand from the November 2011 27 NAVD avg volume change above -12 ft NAVD cumulative volume change above -12 ft NAVD avg volume change above -20 ft NAVD cumulative volume change above -20 ft NAVD avg volume change above -30 ft NAVD cumulative volume change above -30 ft NAVD Reach (Profiles) ft ft cy/ft cy cy/ft cy cy/ft cy cy/ft cy cy/ft cy Fort Macon State Park (103-112) 6,691 179.0 30.9 206,541 68.4 457,405 89.0 595,792 84.4 564,734 79.2 529,807
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Bogue Banks Beach - Carteret County Shore Protection Office

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