The Dare County Beaches (Bodie Island) Shore Protection Project includes the towns of Kitty Hawk, Kill Devil Hills, and Nags Head along the Outer Banks of North Carolina. The design is to construct a 25-ft wide, 13-ft (ngvd) high dune fronted by a 50-ft wide berm at an elevation of 7-ft (ngvd). In 2004, the South Atlantic Division, Wilmington District (SAW) initiated physical and biological monitoring to assess the performance of the project. SAW partnered with the USACE Engineering Research and Development Center, Coastal and Hydraulics Laboratory’s Field Research Facility (FRF) located in Duck, NC for the physical monitoring. The FRF is well known for conducting a long-term, uninterrupted, comprehensive, coastal monitoring program. Data collected under the physical monitoring plan will be used to assess the beach response to the fill placement and will serve as the basis for maintaining the project. The physical monitoring will also be used to address the dispersion of the fill from the project limits to adjacent non-project areas. This monitoring will also provide data in support of the biological monitoring effort being undertaken by another contractor. For this reason, the physical monitoring extends outside the project limits to include control areas to assess potential environmental impacts.
The physical monitoring, which began in 2004, will cover the pre-, during- and post-construction phases of the project. The plan includes continuous operation of a single directional wave gauge and current meter. This gauge will be used to provide a general wave climate and will be re-located approximately annually to address a number of specific issues. The initial location is in the lee of a northern borrow site. The next location will be close to where sand is initially placed on the beach. At some point in the future, the gauge will be returned to the initial location to determine if excavation has caused a change in the wave characteristics. Bathymetric and topographic surveys will be used to determine how the sand fill adjusts to the wave and current processes.
The monitoring plan calls for beach and nearshore profile surveys to be taken every 1000-ft starting in Southern Shores 3 miles north of the Town of Kitty Hawk and continuing south to Oregon Inlet, Figure 1. Each of the 144 profile lines extends from a stable point landward of the dune to the -30 feet depth contour. These profile lines will be surveyed twice per year, scheduled for the spring (Mar-Apr) and fall (Oct-Nov). Sediment samples will be collected along selected beach profiles.
Five sediment samples along the onshore portion and 5 along the offshore portion of select profile will be used to document pre-construction sediment characteristics and any changes that may occur associated with fill placement and future project maintenance. The last major component of the monitoring will be semi-annual aerial photography.