International Dredging Review

International Dredging Review

The New York District Corps of Engineers has let two major dredging contracts to stabilize the protective dunes on New York’s Fire Island and will advertise two additional contracts at the beginning of 2016.

The entire project includes 19 miles of beach from Robert Moses State Park on the west end of the island to Smith County Park at the east end.

“This project is designed to provide coastal storm risk management from coastal erosion and tidal inundation through construction of a beach berm and dune from Fire Island Inlet to Moriches Inlet New York” said Ken Wells Corps spokesperson with the New York District.

Fire Island is a barrier island in Long Island Sound that fronts Long Island. The beachfront is managed by the National Park Service as Fire Island National Seashore and a sand dune running the length of the island protects the communities on the island and the mainland from storm surges.


The Dutra shore crew moves sand to shape the berm and dune. The berm visible beyond the truck has an elevation of +9.5 feet and a crest width of 90 feet protecting the +15 foot dune under construction beyond it. Photo courtesy of the Dutra Group

On October 29 2012 Hurricane Sandy flattened or severely eroded most of the Fire Island dunes and lowered the elevation of the beach leaving the surviving dunes vulnerable. Erosion allowed overwash along approximately 45 percent of the island carrying large volumes of sand to the center of the island. The island was breached in two locations at the east end of the island.

One of the breaches in Smith Point County Park at the east end of the island was filled in immediately in accordance with the Breach Contingency Plan (BCP) enacted in 1997. The other breach was in the Otis Pike High Dune Wilderness area. The BCP calls for monitoring and evaluating a breach within the wilderness area rather than filling it. Since the breach remains relatively stable the BCP team has left it as is but continues to monitor it to see if it will close naturally.


Dutra crews placing sand to start construction of the dune and berm structure using sand brought by the Stuyvesant from an offshore borrow area and stockpiled by shore equipment. Photo courtesy of the Dutra Group

The Disaster Relief Appropriations Act of 2013 P.L. 113-2 authorized and funded the Fire Island Inlet to Moriches Inlet (FIMI) Stabilization Project designed to quickly protect Fire Island and the mainland communities. It consists of a one-time sand placement along the 30 miles of the island. The Corps executed a partnership agreement for the project with the State of New York in August 2014 and awarded the first of four dredging contracts – to Dutra Dredging – in October 2014.

The protective sand structure will consist of a dune fronted by a wide berm on the seaward side. Where the previously-existing dune is still viable only a berm will be placed. Areas that meet the “berm only” criterion include Robert Moses State Park western Smith Point County Park and the TWA Memorial Beach at Smith Point Park.


Dutra Dredging is performing the first contract at Smith Point County Park on the far east of the island. Great Lakes Dredge and Dock will start this fall on Contract 2 at the western end of the island from the Robert Moses State Park east to Lonelyville. Contract 3a will be from Kismet to Seaview and 3b will be from Ocean Bay Park to Davis Park. Map courtesy of the National Park Service

The “small” template is proposed for areas with limited oceanfront structures such as Smith Point County Park. It includes a berm with a vegetated dune having a crest width of 25 feet at an elevation of +13 feet NGVD.

Fire Island Lighthouse Tract will have a modified “small” design template. It will include an unvegetated dune 3800 feet long with an elevation of +13 NGVD side slopes of 1V:10H and a 25 foot crest width.

The “medium” design template is proposed for areas that have the greatest potential for damages to oceanfront structures and includes the 17 communities on Fire Island (including Kismet to Lonelyville Town Beach to Corneille Estates Ocean Beach to Seaview Ocean Bay Park to Point O’Woods Cherry Grove Fire Island Pines Water Island and Davis Park). This design includes a 90-foot-wide berm with an elevation of +9.5 feet NGVD and a 25-footwide vegetated dune of +15 feet elevation. The dune slope is 1V:5H and the foreshore slope is 12H:1V.


The breach at Old Inlet caused by Hurricane Sandy in October 2012 remains stable and is under observation by the Breach Contingency Plan team. Because it is in a wilderness area the team did not fill the breach when it occurred. Photo courtesy of the National Park Service

In the area between Atlantique and Robbins Rest a modified “medium” design template is planned. Approximately 900 feet of the proposed dune northward to the existing vegetation will be re-aligned in an effort to conserve partial overwash habitat that formed in this area due to Hurricane Sandy. The dune design template in this area includes a berm width of 90 feet at an elevation at +9.5 ft NGVD and a vegetated dune with a crest width of 25 feet at an elevation of +15 ft NGVD with a dune slope of 1V:5H and a foreshore slope of 12H:1V.

Additional beachfill is planned for only a few of the reaches – at Robert Moses State Park at the Fire Island Lighthouse at the request of  the National Park Service at all the communities outside of Federal Tracts and at Smith Point County Park.

Dutra’s contract is to restore the dune and berm structures at Smith Point County Park. It was the first to be awarded because the park is the most vulnerable area of the entire FIMI Project. It has the lowest existing elevation which leaves it vulnerable to overwash and breaching.

The $47.9 million contract calls for placement of 2.5 million cubic yards of sand for dune and berm structures including dune grass plantings in addition to beach fill. Work on this first contract also includes approximately 100 acres of habitat maintenance and enhancement for endangered piping plovers.

Dutra’s hopper dredge Stuyvesant is dredging sand from the ocean near Hampton Beach for the project which is scheduled to be complete at the end of this year.

The second project – emergency stabilization from Robert Moses State Park at the western edge of the island east to Lonelyville – a distance of approximately four miles — was awarded to Great Lakes Dredge & Dock in January 2015 for $23383400. Using the hopper dredge Liberty Island Great Lakes will begin this fall to place sand to construct a berm in the area of Robert Moses State Park and a berm and dune in areas east of the park. The Liberty Island will dredge approximately 1100000 cubic yards of sand from a borrow area about 10 miles offshore of the project site. Work is expected to be complete by early 2016. Construction of vehicle and pedestrian crossovers are also part of the project.

Upcoming contracts 3a and 3b also involve sand placement and dune construction but the planned dune structure encroaches on about 300 residences and the Corps of Engineers must acquire these real estate easements before these contracts can be awarded.

This aspect has attracted public attention as many of the houses have been in place for decades and they define the owners’ lifestyles. However for the dune to remain viable it must continue in an uninterrupted straight line and the acquisition of the properties is proceeding.

The first community contract – 3a Kismet to Seaview – is expected to be awarded in early 2016. The second contract 3b Ocean Bay Park to Davis Park is expected to be awarded in summer 2016 – contingent on the real estate acquisitions.