- Home
- Departments
- Departments I - Z
- Shore Protection Office
- Preservation Plan
- Dredged Material Management Plan (DMMP)
Dredged Material Management Plan (DMMP) - Morehead City Harbor
|
---|
UPDATES (2017) |
UPDATES (2014) |
UPDATES (2010-11) |
Project Background (< 2010) - Brandt Island Pump-Outs |
PROJECT BACKGROUND (>2010)
Beginning in federal Fiscal Year 2011 (October 1 2010 – September 30, 2011) the U.S. Army Corps of Engineers (Corps) begun implementing a rotating 3-year cycle "Interim Operation Plan" that was developed in order to adequately maintain (dredge) the Morehead City Harbor Federal Navigation Project. Generally speaking, we can segregate the harbor into either those areas that shoal with beach quality sand, or those areas that predominantly shoal with non-beach quality sediments (silt and clay). The areas of the navigation channel closest to Beaufort Inlet proper tend to shoal with beach quality material, while the areas closer to the N.C. Port facility and the most seaward reaches of the channel tend to shoal with non-compatible material.
View Graphic: Morehead City Harbor site map and sediment zones
Importantly, the Corps and the National Park Service (NPS) also concomitantly developed a Dredged Material Management Plan (DMMP) addressing longer term dredging and disposal issues at the harbor encapsulating a twenty year time horizon. A draft of this later report was released in October 2013 and a second draft/final in June 2016; and is all part of a legal settlement the Corps and Carteret County agreed to in December 2008. Thus, the Interim Operation Plan fully transitioned to the DMMP in FY 2017 (October 1, 2016 - September 30, 2017).
Year 1 (2010-11, 2013-14, 2016-17, 2020-21, etc.) of the Interim Operation Plan/DMMP includes dredging maintenance of the “beach quality” zone of the harbor near Beaufort Inlet with concurrent nourishment to the beaches of Ft. Macon and Atlantic Beach (i.e., the sand is dredged from the inlet and placed directly along the beach). The accompanying figure depicts the navigation project (channel) footprint, the channel areas to be dredged in winter 2020-21, and the general geographic limits of beach nourishment.
View Graphic: Scope of work for winter 2020-21
Roughly 1,143,000 cubic yards of sand will be dredged and utilized for beach nourishment over a total of approximately 2.43 miles of shoreline in “Year 1” of the DMMP. As a quick mental image, a standard dump truck holds roughly 15 cubic yards of dry sand meaning the nourishment effort planned for this winter is equivalent to roughly 76,200 dump trucks worth of sand, or encompasses enough sand to extend a NCAA regulation basketball court roughly 6,556 feet up in the air. The contract has been awarded to Weeks Marine for a total of $18,086,750, and dredging/nourishment activities must be completed between November 16, 2020 and April 30, 2021. This is considered as the “environmental window”, and is designated as the timeframe when the impact risks associated with dredging and nourishment to both land- and water-based habitat and wildlife are at their minimum.
Year 1 is the only phase of the Interim Operation Plan that places sand dredged from the harbor along the beaches of Bogue Banks. Year 2 (2011-12, 2014-15, 2017-18, etc.) includes “touch-up” dredging of the outer harbor with nearshore disposal (~250,000 cubic yards), and Year 3 (2012-13, 2015-16, 2018-19, etc.) includes a more robust maintenance event for the outer harbor, with an estimated 750,000 cubic yards of sand to be disposed in the nearshore disposal area. Areas of the harbor containing non-beach compatible shoal material will be dredged in Years 2 and 3, and will be disposed in either Brandt Island (identified in the accompanying figures), or dumped in the southwest corner of the Offshore Dredged Material Disposal Site, located roughly 3 miles offshore.