Beach Replenishment Update

The borough of Mantoloking recently published the following update regarding beach replenishment:

Here is an update on the status of the replenishment project.  I “borrowed it” from Bob Hopkins who lives in Seaside and is tracking the project with great frequency (thanks Bob!).  Bob mentions project specifics for Seaside— with the help of Bob Mainberger, I have added Mantoloking specific information in red.

We will hopefully have some more news in the next month or so.

Councilman Chris Nelson

The United States Army Corps of Engineers (USACE) has been authorized to complete the Manasquan Inlet to Barnegat Inlet Storm Damage Reduction Project.  The primary purpose of the project is to reduce the risk of coastal storm damage to the communities located on the barrier peninsula in Northern Ocean County, NJ.  The project area includes the municipalities of Point Pleasant Beach, Bay Head, Mantoloking, Brick Township, Toms River Township, Lavallette, Seaside Heights, Seaside Park, and Berkeley Township. The project consists of a continuous beachfill along 13.7 miles of ocean shoreline and consists of placing and shaping the beachfill material into a berm and dune system. The estimated quantity of sand to complete the beachfill for this project is 10.7 million cubic yards.  In addition, the project will incorporate construction of various dune cross-overs, planting of dune grasses, and the placement of sand fencing. The New Jersey Department of Environmental Protection (NJDEP) is the cost sharing Non-Federal Sponsor (NFS) for this project.
In order to begin construction of the project, specific easements are required to be signed by the underlying property owners for the portion of their parcels that the project features will be constructed. The easements do not take ownership of property, they only grant permission to the USACE to construct the project on the specific portion those properties and the NFS, along with the communities, to operate and maintain the project for the life of the project, which is as long as the project remains an authorized federal project.

The NJDEP, as the NFS, is responsible for securing the easements. They have been working closely with the municipalities and the NJ Attorney General to obtain all the necessary easements.  The majority of the easements needed have already been obtained.  Those that have not been signed by property owners will be obtained by the NJDEP through the prescribed state eminent domain processes.

The original USACE plan was to build the entire project length all at once, but because of the various stages of the continuing legal proceedings of the different municipalities to secure the needed easements, the NJDEP has asked the USACE to consider proceeding with the construction in segments.  The reason for this is to not delay the vital Storm Damage Reduction Project from the communities that will have their easements in place by the end of this summer.

Currently the expectation is that by the end of the summer the majority of the project area will have the necessary easements to proceed to the advertisement for bids for the construction by the fall 2016, with the exception of Bay Head, Point Pleasant and Berkeley. The entire project length will still be part of the project and the plan is to construct the entire length.  However, due to the uncertainty of when all the easements will be obtained by the NJDEP, the three municipalities above will be options to the initial contract to allow additional time for the legal processes to conclude and so construction can begin on the rest of the project.  The base portion of the upcoming solicitation will include the municipalities from Mantoloking to Seaside Park.  It is expected that construction may commence within the base portion of the project in the first quarter of 2017, with construction continuing throughout 2017 and finishing by the end of 2018.  The remaining segment on the barrier peninsula will be added to the schedule once the Easements are obtained. In terms of Mantoloking, we are still working the DEP and the Attorney General’s Office to obtain four easements.  Two between Herbert and Lyman and another two between Lyman and the Bay Head Border on East Avenue.  For the reasons mentioned above, and in order to proceed with the project, the area between the our Southern Border with Brick all the way to 1071 Ocean Avenue will be included in the big project.  An option from 1071 to the Bay Head border will also be bid.  If all goes as planned, the DEP and the NJ Attorney General’s office fully anticipates for the four remaining easements to be obtained by then and for the project to start and include the entire length of the Borough of Mantoloking.

The crest or top of the new dune in Seaside Park will be at a an elevation of +22 feet measured from the North American Vertical Datum established in 1988 (NAVD88). This is a specific surveying datum.  To give you some perspective, that is about 7 feet higher than the boardwalk in Seaside Park.  The new wider beach berm will be at elevation +8.5 feet NAVD88 which is approximately at the current berm (beach) elevation. The landward toe of the dune will begin at the east edge of the boardwalk which is the construction limit of the project in Seaside Park.  Our current dunes will be incorporated into the new dune which will widen our dunes on the east side and fill in any areas that are currently below the 22 foot level.  The dune will be 25 feet wide at the top and about 160-170 feet wide at the berm elevation.  To the east of the toe of the new dune the post construction flat berm will vary from 225 to 250 feet wide and the foreshore slope from the berm to the waterline will follow the natural slope to the water line.  The width of the beach one year after dune construction is completed will be less than the width of the constructed berm and that will be dictated by Mother Nature.  It will assume the width and contour that is natural for that section of beach.

The crest or top of the new dune in Mantoloking Borough will also be at an elevation of +22 feet  measured from the North American Vertical Datum established in 1988 (NAVD88). This is a specific surveying datum.  That is Approx. 2 feet higher than the sand placed over the new stone revetment north of Lyman Street, between 3 and 4 feet higher than the present average dune heights in the area between Downer and Lyman Streets and Approx. 2 feet higher than the dunes at Downer Street heading south, however as the existing dunes increase in height in the Borough from Downer toward Brick Township, in many locations the new dune will be lower than the existing dunes.  The new wider beach berm will be at elevation +8.5 feet NAVD88 which is about the typical summer beach berm elevation in the Borough. The landward toe of the new dune in many areas of the Borough will match into the existing dune. In areas where needed and as conditions require , they will potentially extend westerly , but only up to 35 feet east of the Borough tax map Dune Reference Line north of Herbert Street and between 20 to 25 feet east of the Dune Reference line south of Herbert Street. The Borough’s current dunes will be incorporated into the new dune which will widen our dunes on the east side and fill in any areas that are currently below the 22 foot elevation.  The dune will be a minimum of 25 feet wide at the top and about 160 feet wide at the base at the berm elevation, with approximately 68’ of the dune foreslope east of the crest width. East of the toe of the new dune, the post construction flat berm at Elevation 8.5 NAVD will vary from 225 to 250 feet wide and the beach foreshore slope from the berm to the waterline will be constructed on a 10 Horizontal to 1 Vertical slope to the water line which matches closely to Mantoloking’s natural slope. Within about 1 year or so, the advanced flat construction berm ,(which includes overfill to compensate for anticipated losses between renourishment cycles), will be naturally eroded to fill in the subaqueous deficit in the existing beach system profile. This may or may not happen gradually, as the berm adjustment will be most dramatic during and following significant storm events until it reaches its natural equilibrium dictated by Mother Nature for each reach of beach.

Once the beach reaches full equilibrium , the Borough should be left with a beach that extends a minimum of Approx. 150 feet from the seaward toe of the new dune to the Mean High Water Line (MHWL) at the end of each the typical planned renourishment cycle.  The system  scheduled renourishment cycle is every 4 years , however , the cycle length between renourishments would typically be adjusted to respond to prevailing weather conditions and erosion experienced during the cycle.

The dune, berm and beach fill will be constructed from sand taken from four borrow sites all about 2 miles off shore between Mantoloking and the northern end of Island Beach State Park chosen to match our beach sand as close as possible in grain size and color.  Pedestrian, ADA accessible, and vehicle entrances over the dune will be built at the same public locations they are now.  The surface of the entrances will be made of a hard packed material that is much easier to walk on than sand.  Dunes built in this manner on LBI in 2006 withstood Sandy very well and provided excellent protection to homes and businesses to the west of the dune.  Currently on LBI, dune construction is underway at several additional locations.  You can get the current status each LBI location by clicking below

http://www.nap.usace.army.mil/Missions/Civil-Works/Long-Beach-Island-Storm-Damage-Reduction/

If you take a trip to LBI you will be able to see the project in various phases at different locations.

Click below to see some commonly held misconceptions on beach replenishment addressed

http://www.nap.usace.army.mil/Portals/39/docs/Civil/Coastal/myths_facts.pdf

 

 

Click below to see some commonly held misconceptions on beach replenishment addressed

 

http://www.nap.usace.army.mil/Portals/39/docs/Civil/Coastal/myths_facts.pdf