Rockaway Beach, a 10-mile-long peninsula facing the Atlantic Ocean in Queens, New York, a borough of New York City, has 850,000+ residents and a great deal of critical infrastructure in a small geographic area ─ schools, hospitals, nursing homes, mass transit lines, etc.
When Hurricane Sandy struck in 2012, more than 1,000 structures were damaged as the sea pushed inland and waves broke against buildings. Nearly 1.5 million cubic yards of sand was eroded from beaches and deposited on oceanfront communities or washed out to sea.
The New York District of the U.S. Army Corps of Engineers aims to reduce risk of such widespread damage from future storms.
District Commander Col. Matthew Luzzatto said: “Sandy was a wake-up call. We know more frequent and severe storms are coming our way. More robust defense systems are needed to safeguard vulnerable shoreline communities ─ especially in the Rockaways which has historically suffered storm damages.”
Reinforced Dune
To that end, the District is constructing a reinforced dune with an impermeable core of steel, rock and concrete to fend off storm and tidal surges. When complete, the dune will stretch nearly seven miles (35,000 feet), providing a stronger line of defense than a sand-only dune. The reinforced dune is designed to defend inland areas from erosion and wave attack during storm events and limit storm surge inundation and cross-island flooding.
The reinforced dune is part of the larger East Rockaway Inlet to Rockaway Inlet Coastal Storm Risk Management Project, a $702 million initiative that also includes beach fill and groins to make the shoreline more resilient.
Construction Process
Here’s how it’s being built:
▶ Nearly two million cubic yards of sand, dredged from an offshore borrow area, is placed on the beach.
▶ Thirty-foot-long sections of steel sheet piles ⎼ with interlocking edges ⎼ are driven 14 feet into the ground to provide the foundation of the reinforced dune. Then the concrete cap is poured on top of the sheet materials using formwork.
▶ Geotextile fabric, core- and armor stones are placed in front of the sheet piles on the seaward side. After it’s buried by sand, 70 acres of plantings with sprawling root systems will be placed on top of the dunes anchoring the sand in place.
Future Enhancement
The reinforced dune was designed for future adaptation to meet rising sea levels by extending the concrete cap and adding another layer of armor stones. District personnel working directly with the project include project manager Michael Oseback, senior coastal engineer Suzana Rice, and project engineer/contracting officer representative Ryan Ferguson.
Professional Staff Oversight
Oseback’s work is hands-on managing the USACE Rockaway project team, making site visits and working with contractors while maintaining consistent communication with project partners; Rice is responsible for much of the planning and design process and engineering support during construction; and Ferguson administers the contract, manages the contractor to ensure safety and quality standards are maintained, and ensures the project is completed on schedule and on budget.
The New York District is working in conjunction with area stakeholders on the project, including the Rockaway Initiative for Sustainability and Equity (RISE), a nonprofit agency engaging residents in caring for the environment and local community. They’re also developing a resiliency plan of their own.
“We want to make sure our work fits in with that [RISE’s vision] so that we have a unified dune system for the entire peninsula,” said Daniel Falt, deputy chief of the District’s Programs and Project Management Division.