NY Announces $336M Flood Risk Protection
Eight years after Hurricane Sandy battered waterfront communities in the Rockaways and across New York City, Mayor Bill de Blasio and Gov. Andrew Cuomo announced late last month that construction on a $336 million coastal resiliency project was officially kicking off.
“Eight years ago, Hurricane Sandy devastated our city and our shoreline,” said de Blasio. “We committed to building back stronger than ever, and I am thankful for our federal and state partners for working together to make this critically important project come to life. Together, we are protecting our shoreline and creating a more resilient New York City.”
The city, the state's Department of Environmental Conservation and U.S. Army Corps of Engineers have all partnered together on the Rockaways-Atlantic Shorefront project.
Flood Protection
Back in 2012, Hurricane Sandy rocked the beaches of New York, damaging or completely destroying more than 1,000 structures on the Rockaway Peninsula, which were reportedly 10 feet high. In addition to damaging the infrastructure, the storm also displaced approximately 1.5 million cubic yards of sand from Rockaway Beach across adjacent communities and/or washed out to sea.
While the U.S. Army Corps of Engineers replaced the loss with 3.5 million cubic yards of sand to restore the beach’s design profile and improve resiliency against erosion and coastal flooding, officials knew that additional actions would still need to be take to protect coastal communities from future flooding, severe weather events, and other impacts in the Rockaways caused by climate change.
NY - Atlantic Shorefront Projects Will Strengthen Rockaway Peninsula @USACEHQ #erosion #coastalengineering https://t.co/DHvJxdETMm pic.twitter.com/oMZvReXeKU
— CoastalNews365 (@CoastalNews365) November 17, 2020
“Climate change is already impacting our everyday lives, and the Rockaways are at the forefront of damaging flooding from strong and more frequent coastal storms driven by warmer temperatures,” Cuomo said. “New York State is proud to partner on this project as part of our ongoing efforts to help New York City and communities across the state build back stronger, smarter and more resilient.”
According to reports, the shorefront project involves the construction of six miles of storm surge flood protection along the Queens waterfront. However, the first phase of the project will see the building out and restoration of nearly 20 stone groin structures—similar to rock jetties—into the ocean to prevent additional sand erosion.
The rehabilitation and construction of these flood barriers are expected to provide stabilization for a re-nourished sand beach and dune and maintain the protective beach profile, as well as help to restore local ecosystems and ensure the long-term viability of endangered species.
Following these efforts, crews intend to reinforce a network of dunes with stone and steel sheet pile walls, achieving a height two feet higher than the original structure, and further protecting the coast from wave breaking pressure. The new structures are also slated to limit surge inundation and cross-peninsula flooding.
Additional sand will also be added to this portion of the beach.
Suffolk County's H&L Contracting LLC will lead construction on the first portion, under a $114 million contract, while an additional $237 million plan to build berms and floodwalls in Jamaica Bay is still in the design process.
"The Rockaways-Atlantic Shorefront Project will bring much needed relief to Rockaway Beach and surrounding communities, limiting coastal flooding and erosion over six miles of shoreline," said Alex Zablocki, Executive Director of the Jamaica Bay-Rockaway Parks Conservancy.
The project is slated to reach completion by 2024.
Other Coastal Barrier Projects
Also announced at the end of October, the U.S. Army Corps of Engineers and the Texas General Land Office released a second draft of its envisioned multi-billion-dollar coastal storm barrier, Ike Dike. Plans for the barrier have reportedly been in the works since Hurricane Ike rocked Galveston, Texas, in 2008, and are expected to cost anywhere between $23 billion to $32 billion.
The system is reportedly composed of 14-foot dunes on the landward side and 12-foot dunes on the Gulf, followed by 250 feet of beach. While the Corps notes that the change will reduce environmental and social impacts, it would also require about 39 million cubic yards of sand for beach and dune construction on both Bolivar Peninsula and West Galveston Island.
Noting on the project’s revisions, one of the biggest changes involves the replacement of a series of levees and floodways previously slated to run parallel to State Highway 87 on Bolivar Peninsula and FM 3005 on Galveston Island with 43 miles of a natural dune and beach system.
Other changes to the project proposal involve updating the storm surge gate between Galveston and Bolivar Peninsula to two 650-foot wide surge gates at the mouth of Galveston Bay, instead of the initially proposed 1,200-foot wide gate. Although the change would reduce the water flow by 10%, the Corps estimates that design change has less of an impact on restricting the flow of water between the bay and the Gulf than previously proposed, adding that the gates would only be closed during the event of a storm.
That same month, the city of Venice reported for the first time in decades that its flood barriers successfully kept the city dry during its first day of acqua alta or “high waters”—seasonal flooding caused by high tides. The barriers, also known as Mose (Italian for Moses), are named from the more functional Modulo Sperimentale Elettromeccanico, meaning Experimental Electromechanical Module.
Made up of 78 submerged gates positioned at the three mouths of the lagoon, the food barrier system was designed with the capabilities to be raised during acqua alta in order to protect the lagoon against high tides ranging from 110 centimeters to three meters. According to reports, these gates are split into four barriers, which include multiple gates to admit vessels through.
In July of this year, the flood gates were tested successfully under the supervision of Italy’s Prime Minister Giuseppe Conte. To date, the project has been reported to cost over 7 billion euros.
At the end of September, Representatives David E. Price (D-North Carolina) and Lee Zeldin (R-New York) introduced legislation aimed at reducing the impacts of severe weather, such as tropical storms, hurricanes, flooding and other risks associated with rising sea levels.
The bipartisan bill is entitled the Flood Resiliency and Taxpayer Savings Act of 2020 and arrives as a pragmatic approach to enhancing the safety of federal investments and communities, while building and rehabilitating in flood-prone areas. Similar to other construction legislation, the bill directs federal agencies to plan for potential future risks (excluding the military with the exception of the U.S. Army Corps of Engineers) in order to augment longstanding flood review processes.
