NCDMF Comment Memo - Dare Buxton Beach Nourishment

ROY COOPER
Governor
JOHN NICHOLSON
Interim Secretary
KATHY B. RAWLS
Director
TO: Heather Coats, NCDCM Beach & Inlet Management Project Coordinator
FROM: James Harrison, NCDMF Fisheries Resource Specialist
SUBJECT: Buxton Beach Nourishment, Dare County
DATE: 6 October 2021
A North Carolina Division of Marine Fisheries (DMF) Fisheries Resource Specialist has
reviewed the permit application for proposed actions that may impact fish and/or fish habitats.
The applicant — Dare County — is proposing to reauthorize the limits of the previously permitted
beach nourishment at Buxton, along with the addition of engineered dune construction along the
developed portion of the shoreline. The project site extends along approximately 2.9 miles
(15,500 linear feet, or LF) or shoreline, which includes the shoreline within the unincorporated
village of Buxton and an additional 11,000 LF of shoreline to the north along the Cape Hatteras
National Seashore.
As proposed, the beach berm would be filled to an elevation of +7' NAVD 88 with a 15:1 slope
out to tie into the existing grade at approximately -5' to -24' NAVD 88. The berm would be
constructed at a variable width ranging from roughly 50' to 250'. Dare County is also proposing
to include an engineered dune along 3,500' of shoreline in Buxton, constructing to an elevation
of +13' NAVD with an average 20' design crest width and a 3:1 slope down to the +7' berm
elevation. As proposed, the maximum volume of excavated volume is 1.2 million cubic yards
(CY) of material, based on current conditions. However, Dare County has indicated with final
templates will be submitted to permitting agencies prior to construction for final approval. It is
currently estimated that 105 acres would be filled below mean high water (MHW) and 37 acres
of beach fill would be placed above the MHW line.
Dare County is proposing to conduct this beach nourishment operation without environmental
windows. The application documents note that the project will require summer dredging due to
safety issues, particularly the lack of safe harbor for ocean dredges. It is expected that the
project duration will be a maximum of 3 months if work is permitted to occur between May 1
and September 15. The Buxton nourishment project application was submitted at the same time
as the Avon project in order to allow the projects to ideally occur simultaneously in the summer
of 2022. This schedule is also consistent with all prior nourishment projects in Dare County
since 2011 and follows the goal of maintaining nourishment at approximately 5-year intervals.
The nourishment project proposal includes a proposed monitoring and mitigation plan. This plan
details the various conditions required by the U.S. Army Corps of Engineers (USACE) and the
National Park Service (NPS). These conditions aid in the protection of resources and
State of North Carolina Division of Marine Fisheries
3441 Arendell Street I P.O. Box 769 Morehead City, North Carolina 28557
252-726-7021

minimization of impacts associated with the project. Additionally, the plan includes an NPS
monitoring plan which has set aside five segments to provide reference zones that will be used to
perform comparative ecological monitoring studies with nourishment project areas. The purpose
of this plan is to evaluate the recovery of physical and biological components of the beach
ecosystem following beach nourishment and to evaluate possible changes to beach
characteristics, such as beach grain size and benthic organisms. As noted in the plan, the
monitoring proposed by the NPS does not intend to duplicate monitoring efforts at the nourished
beach required by other agencies as part of the permitting process, but rather, will work in
collaboration with the permittee and other agencies to determine an appropriate monitoring
approach. The sampling detailed in the plan will occur prior to the nourishment, within two
weeks of completion of nourishment, and seasonally for 2 years after nourishment.
DMF has concerns with allowing the work to be completed year-round, especially taking into
consideration the cumulative area of disturbance for all four towns in one season. Dredge and
fill operations year-round, particularly during the warmer spring and summer months, could
negatively affect the species present in these areas. 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 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 and the habitats they utilize, DMF
typically recommends a moratorium of April 1 through September 30 for dredge and fill
operations. This moratorium protects aquatic resources during periods shown to have high
benthic activity, as well as the time in which many species grow to maturity. Furthermore, it is
the time of year when finfish frequently utilize shallow waters for refuge and/or forage.
Observation of the dredging operations moratorium would help to minimize the potential impacts
to aquatic species in the area. However, since the proposed project would be a continuation of
projects taking place throughout Dare County, 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 above
environmental window in order to minimize impacts, rather than plan on conducting operations
during the window.
The monitoring should include, at a minimum:
1. Pre- and post -placement surveys of benthic species (biodiversity and abundance) in order
to determine the impact of dredged material placement on benthic species at the receiving
beach.
2. If DCM or DMF raises concerns regarding turbidity levels during the proposed project, a
turbidity monitoring regime should be implemented. This would include coordinating
with the resource agencies on remedying the situation.
3. Monitoring for dead fish and crabs along placement - any deceased fish/crabs observed in
disposal areas (those in which the cause of death isn't obviously related to recreational
State of North Carolina Division of Marine Fisheries
3441 Arendell Street I P.O. Box 769 Morehead City, North Carolina 28557
252-726-7021

fishing) should be recorded and reported. This should occur on a daily basis, and
include recordings of the date, time, and location of each specimen, as well as
measurements (if possible). Observers aboard the dredging vessel(s) should also
note any dead species observed during dredging. DMF understands that due to the
nature of dredging, species identification and measurements may not be possible.
Additionally, the Environmental Assessment (EA) drafted for this project notes that it is
anticipated that the nature of the borrow area would result in infill with adjacent sediment.
DMF would recommend that post -dredging surveys be completed in order to verify that
this infill occurs as anticipated.
Thank you for consideration of our comments and concerns. Please contact Jimmy Harrison at
[phone] or at james.harrison(rncdenr.gov with any further questions or concerns.
State of North Carolina I Division of Marine Fisheries
3441 Arendell Street I P.O. Box 769 I Morehead City, North Carolina 28557
252-726-7021