NCDMF Comment Memo - Town of Duck Beach Nourishment

MEMORANDUM: TO: Heather Coats, NCDCM Beach & Inlet Management Project Coordinator FROM: James Harrison, NCDMF Fisheries Resource Specialist SUBJECT: Town of Duck Beach Nourishment, Dare County DATE: 10 May 2021 A North Carolina Division of Marine Fisheries (DMF) Fisheries Resource Specialist has reviewed the CAMA Major Permit application for proposed actions that may impact fish and fish habitats. The applicant is proposing a one-time beach nourishment event that will include sand placement along a 1.6-mile section of the Town’s oceanfront shoreline using dredged material from Borrow Area A. The main placement area begins near the northern property boundary of 140 Skimmer Way and extends approximately 7,914 feet southward, terminating in the middle of the parcel at 137 Spindrift Lane. Additionally, there is one 500’ taper on the north end of the main fill, extending from the northern boundary of the main placement to the property line between 126 and 128 Skimmer Way. The total linear extent of sand placement is approximately 8,414.7’ (1.6 miles). The total fill area below mean high water (MHW) is 3,023,609 square feet (69.41 acres), and the total fill above MHW is 1,488,346 square feet (34.17 acres), for a total disturbed area of 4,511,955 square feet (103.58 acres). Construction of the preferred design, along with five years of advanced fill, would require 806,500 cubic yards (CY) of fill to be obtained from Borrow Area A. The actual volume of dredged material would likely require an additional 20% to account for losses during dredging, as well as an additional amount to account for the unlikely event that a storm would erode the Town’s shoreline prior to construction. In total, the amount of material that could be excavated from the borrow area would be 1,209,750 CY, or 150% of the 806,500 CY required by the preferred design. The applicant is proposing to use the remaining material from the Borrow Area A site, which is expected to have sufficient compatible sediment for use for this project as well as the projects for the three other towns in Dare County. Dredging for the proposed project would be conducted via cutterhead dredge, hopper dredge, or a combination of the two. Construction is proposed to occur year-round, with no start or stop date provided. The Town has indicated a high likelihood that construction would occur during the calmer

summer months. It is expected that the proposed project would take 2.5 months to complete, and that all four projects could be completed within 5 months if completed concurrently, depending on equipment availability, weather, and the ability to work without environmental windows. DMF has concerns with allowing the work to be completed year-round, especially considering the cumulative area of disturbance for all four towns in one season. Dredge and fill operations year-round, particularly during the warmer summer months, could negatively affect the species present in these environments. Potential impacts include direct mortality through burial or entrance into dredge machinery, excessive sediment particles in the water column which can clog gills, or areal avoidance due to the noise and/or turbidity associated with dredge and fill operations. In order to protect the ecologically, recreationally, and economically important finfish and shellfish species, along with the organisms on which they feed, DMF typically recommends a moratorium of April 1 through September 30 for dredge and fill operations. This moratorium protects aquatic resources during periods shows to have high benthic activity, as well as the season in which many species grow to maturity. Furthermore, it is the time of year when finfish frequently utilize shallow waters for refuge and forage. Observation of the dredging operations moratorium would help to minimize the impacts to aquatic species in the area. However, since the project would be a continuation of projects taking place in neighboring towns, DMF is amenable to allowing this one-time nourishment request to occur without a mandatory moratorium requirement. DMF would recommend, though, that monitoring be included to determine the effects this work will have on important nearshore fish and benthic species and habitats. Additionally, DMF would recommend that the applicant make every effort possible to conduct operations during the environmental window in order to minimize impacts. Thank you for consideration of our comments. Please contact Jimmy Harrison at [phone] (office) or [phone] (mobile – preferred), or at [e-mail] with any further questions or concerns.