International Dredging Review

International Dredging Review
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Manson Construction Company began work on the Duval County Shore Protection Project to restore critically eroded beaches and dunes. Under a contract by the U.S. Army Corps of Engineers Jacksonville District, the contractor is pumping approximately 850,000 cubic yards of sand on 8 miles of eroded beaches, including Jacksonville, Neptune and Atlantic beaches.

Construction began on November 30, 2018, starting along the southern beaches and proceeding north with an expected project completion of January 30. Manson is placing approximately 800,000 cubic yards on the beach berm, immediately seaward of the dunes, and the remainder of the sand is being used to repair dune erosion that occurred following Hurricanes Matthew (2016) and Irma (2017).

Manson is dredging the sand from an offshore borrow area in 50 feet of water and located about 7 miles offshore of Neptune Beach. It is the same borrow area used in the recent 2016 to 2017 renourishment and just south of the borrow areas that have provided most of the sand placed to the project since 1978. Beach renourishment is needed about every five to six years.

The sand is picked up from the seabed by a hopper dredge and pumped through a 30-inch pipeline to the beaches. The placement of sand initially widens the beach by about 50 to 100 feet but is designed for natural erosion to move some of the newly placed sand offshore to rebuild the beach’s foundation, below the waterline.

The $15,682,725 construction costs for the project are shared between the federal government (about 90 percent), and the City of Jacksonville (about 10 percent), with the latter eligible for more than 90 percent reimbursement from the State of Florida and Federal Emergency Management Act (FEMA) grants. The extra level of federal funds for the 2018 to 2019 project arises from special allocations to repair damages from recent hurricanes. The typical cost-share funding for project renourishment is about 61 percent federal, 18 percent state, and 20 percent City of Jacksonville.