INTERIM OPERATION PLAN (2014) - Project Updates

VIEW GRAPHIC: Beach Nourishment Progress Map (Final)

Final Figures
Placement Start Date
April 14, 2014
Placement Completion Date
May 22, 2014
Total Contract Amount
$9,415,774
Dredged Material Quantity (excavated from channel)
1,110,400 cubic yards
Measured Quantity on the Beach (total in place)
1,107,585 cubic yards
Ft. Macon (4,500 feet)
585,067 cubic yards
Atlantic Beach (5,000 feet)
522,518 cubic yards

5/26/14 (project completed May 22nd) – Weeks Marine completed dredging with concurrent beach nourishment along Ft. Macon and Atlantic Beach on May 22nd.  Final figures concerning the total amount of material excavated from the channel, the amount of material surveyed “in-place” on the beach, apportionment of sand between Ft. Macon and Atlantic Beach, etc. will be posted as soon as the data becomes available.  All land-based piping, machinery, etc. was removed from the active beach strand just in time for Memorial Day weekend. 

5/19/14 – Weeks Marine is almost complete with the scope of work associated with this year’s project.   As of this morning, it is estimated that 740,000 cubic yards (cy) of the 775,000 cy total have been excavated and pumped (or roughly 95%).  Concurrent beach nourishment activities have extended to “station 1174+00, which is located just west of the Tom Doe Regional Access, in Atlantic Beach – see progress map.   Roughly 8,300 linear feet of beach have been nourished of the total 8,537 feet anticipated (or 97%).  It is likely the fill will be extended an additional ~150 feet to the west (station 1170+00) as dredging operations are scheduled to conclude on Wednesday (May 21st).

VIEW PHOTOS - MAY 19, 2014

5/12/14 – The current discharge area is located at Commerce Way, Atlantic Beach (station 1190+00 in the progress map above).   Thus far Weeks Marine has dredged/pumped 640,000 cubic yards (cy) and is 82% complete with the excavation component (775,000 total cy for project).  On the beach, the nourishment has extended 6,700 linear feet, representing 78% of the total 8,537 feet nourishment reach.  Notwithstanding any major mechanical or weather issues, Weeks Marine could be completed with the project a week from now.   

  

VIEW PHOTOS - MAY 12, 2014

 

5/5/14 –The discharge area is currently located near Tar Landing in Atlantic Beach (station 1210+00 in the progress map).  Weeks Marine should complete the seaward portion of the channel cut this week and begin working “inside”; closer to Shackleford Banks.  

  

VIEW PHOTOS - MAY 5, 2014

 

4/28/14 – Nourishment/disposal activities is currently located at the Ft. Macon State Park/Town of Atlantic Beach border (see progress map).  On the beach, Weeks Marine made roughly 1,400 linear feet of progress in the past week as they continue to work off a y-valve configuration (see schematic). As of this morning, approximately 58% of the shoal material (450,000 of the 775,000 total cubic yards) was placed on 50% of the beach reach (4,300 of 8,537 total linear feet).  Sediment quality varies depending on the discrete reach that is being actively dredged.  For the most part, shoaling in the more “offshore” portions of the channel includes predominantly finer-grained sand while conversely shoaling material that enters the channel near the tip of Shackelford Banks is comprised of coarser-grained sand and shell gravel.   

 

VIEW PHOTOS (includes comparisons) - APRIL 28, 2014

 

4/21/14 – Weather and sea conditions has hampered dredging/nourishment activities this past week, but Weeks Marine made over 1,300 linear feet of progress on the beach.  The discharge area is currently located at the Ft. Macon Bath House Access/rock groin (see progress map and photos).  

 

VIEW PHOTOS - APRIL 21, 2014

 

4/14/14 (PROJECT START) – The Weeks Marine cutterhead pipeline dredge, the CR McCaskill initiated dredging of the channel at roughly 10:30 pm Saturday night (4/12/14) with concurrent beach nourishment along Ft. Macon – currently situated between the rock groin near the inlet and the bathhouse (see photos immediately below).  Approximately 1,500 feet of the beach has been nourished thus far (see progress map).  Overall, the Corps of Engineers estimates 775,000 cubic yards of shoal material will be removed from the channel and placed along 8,537 feet of beach encompassing much of Ft. Macon (oceanside) and a small stretch of Atlantic Beach.   Assuming a 10% loss, the average fill density will be roughly 82 cubic yards per linear feet (cy/ft).   A standard dump truck holds roughly 15 cy of dry sand as a mental image.  Weeks Marine anticipates completing this maintenance event on May 27th, which is beyond the environmental window for beach disturbances associated with beach nourishment - the Corps of Engineers requested and is currently coordinating an extension to this effect.     

 

VIEW PHOTOS - APRIL 14, 2014

 


HOW TO INTERPRET THE PROGRESS MAP
for Interim Operation Plan

Weeks Marine will be utilizing a cutterhead-suction pipeline dredge for the 2013-14 Interim Operation Plan effort.  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 piling, called spuds.  Additionally, a land-based booster pump could be utilized for the Interim Operation Project to provide additional power to pump dredged sand for a maximum distance of approximately 3 miles (extending from the channel westward close to Henderson Drive, Atlantic Beach.   

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 of 2013-14 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 “1162” and “1212” on the graphic above is approximately 5,000 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 as “1162+00”, “1212+00”, etc.