DMMP 2021 - Project Update

VIEW GRAPHIC: Beach Nourishment Progress Map (1/18/2021)



1/18/2020 - PAUSE IN OPERATIONS.  The J.S. Chatry headed for safe refuge in the inner harbor on Friday (1/15/2021) and sits there this morning as the field crews broke down the land pipe and dressed the completed section of the beach, which basically extends from east to west across the Ft. Macon Bath House access area.  They have roughly a 1,000 feet to go before the beachfill enters Atlantic Beach proper once dredging operations re-start - presumably some time later this week (see 1/18/2021 update).  Also once the land pipe is reconfigured, Weeks Marine will create sand ramps over the pipe every several hundred feet and at major access points to enable the public to access the water in the completed sections of nourishment.

1/12/2020 -
PROJECT START (JANUARY 6, 2021).  Weeks Marine's cutterhead-suction pipeline dredge, the J.S. Chatry arrived to Morehead City Harbor on December 29th, and transited to the most seaward reach of the channel to start dredging with concurrent beach nourishment on January 6th.  In terms of the beachfill,  the dredged sand is pumped through a submerged pipeline from the channel that lands west of the terminal groin at Ft. Macon State Park where the land-based pipe is affixed to.  The beachfill starts east of the Ft. Macon State Park “Bath House” Parking/Access area (station 1231+86) and will progress westward from that point to the Circle in Atlantic Beach.  The discharge point this afternoon was located just past the “Bath House” Parking/Access area (station 1219+00) heading towards the Atlantic Beach Town Line  (SEE 1/12/2021 PROGRESS MAP).  This equates to approximately 1,300 linear feet of beachfill thus far.

 PHOTOS - 1/12/2021
Actively Pumping Labeled Photo Photo at Bath House  Double Discharge

12/21/2020 - ANTICPATED START IS 1st WEEK of JANUARY 2021.  The mobilization/staging process continues and Weeks Marine's cutterhead-suction pipeline dredge, the J.S. Chatry is scheduled to arrive the 1st week in January and could begin channel maintenance/nourishment on January 5th.  Staging photos below. 

 STAGING PHOTOS - 12/19/2020
Weeks Marine Sign Bath House Staging   Beach Staging

 

12/3/2020 - STAGING BEGINS.  Weeks Marine is anticipating the first delivery of pipe this week via flat bed trucks with the staging area located along the east periphery of the Ft. Macon "Bath House" Regional Access.  Please remember the staging area and parts of the beach should be considered as a construction area for the time being so please be cautious.   

11/23/2020 - SCHEDULE.  A Notice to Proceed (NTP) has been issued to Weeks Marine by the U.S. Army Corps of Engineers, and we are expecting initial mobilization of personnel and equipment to the Harbor and beach to begin in early December with dredging/nourishment to commence during the very latter stage of December.  Weeks Marine will likely complete the work by the end of March 2021.

SUMMARY & HOW TO INTERPRET THE PROGRESS MAP
for Morehead City Harbor Dredging & Concurrent Beach Nourishment (2021)

Weeks Marine will be utilizing their cutterhead-suction pipeline dredge, the J.S. Chatry for the 2020-21 dredging and beach nourishment event planned under the auspices of the Dredged Material Management Plan (DMMP) developed for the Morehead City Harbor.  A cutterhead-suction dredge utilizes a crane situated on a barge that positions the cutterhead, which looks like a gigantic drill bit, along the seafloor.  The cutterhead agitates the sandy bottom, and the resulting slurry of sediment and water is subsequently suctioned into a long tube transitioning into a pipeline that can be extended to a specific target area (beach, upland disposal site, etc.).  Pipeline dredges are usually not self-powered, but are towed to the dredging site and secured in place by special anchor pilings, called spuds.  The J.S. Chatry has enough horsepower to pump the sand a maximum distance of approximately 4.25 miles extending from the channel westward close to the Circle.     

Project engineers use “stations” positioned along the beach to monitor construction progress and to verify in-place volumes of sand placed on the beach by dredging contractors. The progress map above provides a detailed view of the project reach to be completed in winter/spring 2021 with the location/identification of the station numbers.  The shaded areas in red represent the completed portions of the project and will be updated on a weekly basis throughout the construction.

 

The station numbers included in the progress map conveniently correspond to thousands of linear feet along the beach. For instance, the distance between station “1212+00" and “1138+00” on the graphic above is 7,400 feet. If you visit the beaches of Ft. Macon and Atlantic beach this winter, you may see wood or metal stakes at the base of the dunes that will identify these station numbers by 100 feet intervals as “1162+00", “1163+00”, etc.  The total linear distance of beach nourishment planned is 12,836 feet (2.43 miles).

The total estimated volume of shoal material to be excavated/dredged from the Morehead City Harbor is 1,143,000 cubic yards (cy) - mostly from the areas known as the "Range B, Cutoff, and Range A".  As a mental image, a loaded dump truck can hold roughly 12 cy (wet) or possibly 15 cy (dry) of sand.  The contract price is $18,086,750 and the average fill density is expected to be close to  89 cy/ft = 1,143,000 cy/12,836 linear feet.  The environmental window for the effort closes on April 30, 2021, and the contractor is required to complete the project by this date.