Long-Term Wave Data Measurements in Support of Coastal Studies for the City of Norfolk, VA.
The City of Norfolk, Va. was looking to revitalize sections of its shoreline along the Chesapeake Bay. Long term beach management and protection was therefore required. Local waves and currents are the key drivers of the coastal processes, but storm events can result in significant erosion. Previous numerical modeling studies for coastal projects had relied on numerical modeling of offshore measured waves and wave data from the USACE FRF on the Atlantic Coast in Duck, NC. Therefore a decision was made to conduct long-term measurements to obtain more accurate data on wave climate using a Nortek AWAC wave meter. As long-term performance of the system was a concern, this project allowed not only for useful data to be collected but provided a test of the long term durability of the instrument.
The City of Norfolk purchased the equipment and contracted with RPS (formerly Evans Hamilton), to deploy, service and maintain the instruments as well as to the analyzed data. Subsequent to the QA/QC process, the final data was provided to Moffatt Nichol for their coastal infrastructure design use for City projects.
In general, the data was used to evaluate the wave and current climate along shoreline and to provide input to numerical models for assessment of erosion, shore stabilization solutions, storm protection, beach nourishment projects and better design decisions. The system also provided measured field data to evaluate storm event impacts, was used to aid in the development of Bay Oaks Beach protection and extension to East Ocean View breakwater field and a study and modeling effort on the West Ocean View and Willoughby Spit regions of the shoreline.
The data is also being used by the USACE to support the General Reevaluation Report (GRR) for the Willoughby Spit and Vicinity Hurricane Damage Reduction Project. The GRR will study and analyze the effects of coastal storms on the shoreline south of Willoughby Spit to Little Creek Inlet.
The AWAC has physically held up well over life of the project which has now extended what is now almost a 10 year deployment. The electrical components have experienced some issues but are still serviceable, and the data quality has not decreased and relatively few data quality issues have been encountered over the deployment period. The results of the study have save the City many hundreds of thousands of dollars in material and construction costs through informed design improvements.