Attention Must Be Paid to Bayside Flooding at Jersey Shore, Reports Army Corps
NJ’s barrier islands at high risk, in part because of vulnerability to rising waters in back bays, not just storm surges on ocean side
A two-year, $19.5 millionreleased this week identifies back-bay flooding on New Jersey's barrier islands as one of nine high-risk areas along the Northeast coast that most warrant additional attention.
While most of the focus and risk-prevention strategies thus far have been focused on the coastline -- where powerful wave action destroyed homes during Hurricane Sandy -- many residents in places like Sea Bright, Seaside Heights and Atlantic City also experienced flooding that came from the bayside.
Bayside flooding was a problem even before Sandy, and it’s only expected to worsen in the years ahead.
"Hurricane Sandy brought to light the reality that coastal storms are intensifying and that sea-level change and climate change will only heighten the vulnerability of coastal communities,” Brig. Gen. Kent Savre of the Army Corps North Atlantic Division said in a news release announcing the report.
Also highlighted by the report was the vulnerability of the New York-New Jersey Harbor and its tributaries.
The North Atlantic Coast Comprehensive Study (NACCS) was commissioned by Congress in the Disaster Relief Appropriations Act of 2013. It brought together government experts as well as representatives from NGOs and academia to examine present and future flood risks in a 10-state area from New Hampshire to Virginia.
The report analyzed the potential impacts of sea-level rise on areas impacted by Sandy, and it included a nine-step, customizable framework to assist local officials in identifying and reducing risks in their communities.
“In New Jersey, coastal storm risk is managed along the Atlantic Ocean coast by a number of Federal coastal storm risk management projects,” the study said. “However, the low-lying areas of tidal rivers, back bays, and Delaware Bay coasts have a limited number of coastal storm risk management projects.”
It was in some of these areas that didn’t have Army Corps dunes or beach replenishment projects that damage was most extensive.
One part of the study, an Army Corps assessment of land elevation on Long Beach Island and other islands found that just a 1-foot increase in sea level would lead to a significant amount of the island becoming gradually submerged with water from the bay, with only the beach berm and dune systems escaping most of the harm.
Planners and environmentalists say the increased attention being paid to back bays is necessary to help communities better prepare to manage their future flooding risks.
"Although the dunes and the ocean front get lots of attention because those are the places where the boardwalks are and where lots of our tourism is focused, it's really been more and more recognized post-Sandy that it's the back-bay communities (where) we really have to focus our risk and hazard mitigation attention," Lisa Auermuller of the Jacques Cousteau Research Reserve in Tuckerton told. "Those are going to be the areas that are on the front line of seeing the most inundation effects."
In addition to the threat of rising sea levels, the study noted continual erosion of shorelines, the potential for more intense hurricanes, the population density of the area, the growth of coastal communities and resulting stresses on infrastructure, risks to seaports and the aging population in the region.
It looked at several flood mitigation strategies, with a focus on improving natural defenses. The report appeared tofor large-scale hard infrastructure, such as the proposal to build a massive storm surge barrier in New York Harbor. While the Army Corps says such barriers may be appropriate at times and do provide excellent protection against floods in the short term, they can’t adapt to sea-level rise, prevent erosion or provide as many side benefits as preserving wetlands or buying out homeowners who live along the water.
Among the Army Corps recommendations are increased attention to land-use planning, improved education on flood risk, better use of pre-storm planning and post-storm monitoring tools, and an “all of the above” mitigation strategy that includes structural, nonstructural, programmatic and nature-based approaches to reducing flood risks. In the most sensitive areas, the report also suggests that a “strategic retreat” from the coast might be the best option.