U.S. Army Corps, DEP Offer Update on Back Bay Flooding Study

Oct 03, 2018
Photo by: Margaret Thomas Buchholz

Possible solutions to back bay flooding including storm surge barriers, tide gates, levees and floodwalls are being scrutinized by state and federal agencies studying the issue.

The U.S. Army Corps of Engineers is partway through a multiple-year study of back back flooding along the New Jersey coast, and last month hosted two public meetings, alongside the N.J. Department of Environmental Protection, to discuss the scope of the project and potential mitigation strategies, and to field feedback from area residents. A tentatively selected plan is scheduled to be unveiled in December, and a draft interim report/environmental scoping document will be available for public comment in early 2019.

As representatives explained at the meeting at Ocean County College in Toms River, construction of the selected solution or solutions would not be expected to commence until 2026, after compulsory steps that include congressional approval and funds appropriation.

The reason for the study is summed up on the Army Corps website: “Historic storms, including Hurricane Sandy, have severely impacted the back bay communities of coastal New Jersey. The New Jersey Back Bay Study developed out of the larger North Atlantic Coast Comprehensive Study, which identified nine high-risk areas on the Atlantic Coast for further in-depth analysis. The study area is located behind the New Jersey barrier islands of Monmouth, Ocean, Burlington, Atlantic and Cape May Counties and includes the set of interconnected water bodies and coastal lakes that are separated from the Atlantic Ocean.

“The purpose of the study is to investigate coastal storm risk management strategies and solutions to reduce damages from coastal flooding affecting population, critical infrastructure, critical facilities, property and ecosystems.”

Besides the suggested structural solutions, non-structural solutions include elevation of homes and nature-based strategies such as marsh restoration and the creation of living shorelines.

“We understand the importance of this study to everyone here,” said facilitator Alison McLeod, DEP government relations. The department, she added, recognizes “there isn’t a one-size-fits all” solution to back bay flooding. The Army Corps and DEP aimed, during the meetings, to present preliminary results and the current status of study, which is ongoing.

“We will be showing you some possibilities, some options … (but) nothing has been decided yet,” she emphasized.

McLeod was joined at the meeting at OCC by Bill Dixon, director of Division of Coastal Engineering for DEP; J. Bailey Smith, from the Army Corps, the project manager for the study; and Peter Blum, chief of Planning Division for the Corps.

“One of the things we want to stress is that we get nowhere without you, without your input,” Blum said to the audience, adding, “This is the first time we ever had the authority and the funding to study the flooding on the back bay areas.

“We’ve got the oceanside covered, literally,” he noted, referencing the beach and dune replenishment projects up and down the state’s coast. “It’s very important that we address this” – the flooding from the bays.

As Dixon pointed out, “The reason why the department is willing to spend the money for this study is: We need to find out the answer, from the Army Corps of Engineers, as to what they can do to assist the state and the local municipalities with flooding from the bay.”

The beach restoration projects, he remarked, “started this exact same way,” with a study. “This is a large-scale issue,” said Dixon. “This is going to need all levels of government to work together for more resiliency for our state.”

Smith stated the study goals: coastal flooding and sea level rise risk management; reduction of damages that affect the population, property, infrastructure and ecosystems; implementation of system-wide structural, nonstructural, natural and nature-based solutions; and scaled and incrementally implementable construction opportunities

“The flooding will likely not get better,” said Smith, who displayed a sea level rise inundation map.

The Corps, he added, “applies resilience thinking through four principles that spring from the following definition of resilience: the ability to anticipate, prepare for and adapt to changing conditions and withstand, respond to and recover rapidly from disruptions.”

So far, the back bay flooding mitigation study has accomplished public, stakeholder and agency meeting input; technical analyses that include management measure and alternative plan screening/formulation; economic modeling and benefit calculations; storm surge barrier hydrodynamic modeling; natural and nature-based features incorporation; and sea level change and risk-informed decision-making.

The study has also garnered congressional and state support, and a funding stream has been authorized and appropriated.

During the public comment portion of the evening, James Hopkins of Stafford Township expressed concern about a guarantee of funding when the time comes to actually move into the construction phase of the mitigation project. “So far, there has been a lot of support for this study,” said Blum. “I can’t say what’s going to happen on a year-to-year basis, but so far so good.”

Blum, Dixon and Smith also spent a portion of the meeting describing the various concepts under consideration, including storm surge barriers, for which the state and federal agencies have looked to Seabrook, in New Orleans, LA, and the Netherlands, as examples.

Meanwhile, “a floodwall is a much more robust structure than the bulkheads you might be familiar with,” said Smith. “It requires a significant construction element.” Concerns with floodwalls include aesthetics, as the walls create a visual barrier. In addition, there seems to be less floodwall possibility for the northern section of the project, which includes LBI.

Primary nonstructural measures the agencies are exploring include building retrofits – elevation, floodproofing, ring walls – as well as acquisition and relocation, which are recommended in combination with structural measures to formulate economically justified hybrid plans.

Meanwhile, the primary nature-based feature under consideration is living shorelines, current criteria for which includes unarmored shorelines adjacent to infrastructure, complementary to structural measures such as floodwalls and levees.

The study is also investigating modifications that can be made to structural measures to increase habitat value, such as habitat benches to restore more natural slope along shorelines, or textured concrete to support colonization of algae and invertebrates.

An economic analysis has also been undertaken as part of the study, with a deep dive into proposed project effectiveness and comparison of economic benefits and construction costs.

The public’s comments focused on, among other topics, project cost; timeline, which many see as unacceptably protracted; long-term maintenance of structural solutions; and concern about environment.

“Environment is paramount as we move forward,” Smith assured the audience.

“We’re confident in being able to complete the study, and fund the study,” Dixon stated. “Once the study gets completed, and a plan is selected, and all the costs are identified … there are going to be very hard decisions. Will Congress fund it? Will the state of New Jersey partner with the Corps to build it? Will municipalities support building it?

“These are all unanswered questions … and it takes a feasibility study to start the conversation and to determine what the federal government could do, and then choices have to be made by the non-federal sponsor as to what we can or will fund.”

“We got there with the oceanfront projects,” said Smith, “and we’re going to get there with the back bay projects.”

Detailed comments on the study can be emailed to PDPA-NAP@usace.army.mil or mailed to U.S. Army Corps of Engineers, Planning Division, 100 Penn Square East, Philadelphia, Pa. 19107.

Juliet Kaszas-Hoch

juliet@thesandpaper.net

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