Virginia Beach and the federal Army Corps of Engineers are in the early stages of a plan to build a flood barrier across Lynnhaven Inlet.
The project would include a series of tide gates fronting the Lesner Bridge to protect neighborhoods from surging waves during storms.
Five environmental nonprofits — Lynnhaven River Now, Wetlands Watch, the Environmental Defense Fund, the Southern Environmental Law Center and the Chesapeake Bay Foundation — recently banded together to voice concerns about the project.
The groups urge officials to accurately assess how the project could affect the river’s communities and ecosystem, factoring in changing climate conditions and prioritizing cost-effective natural solutions.
“They're in this preliminary design phase, and that's when you want to make really hard, good decisions about what we think the risk is going to look like,” said Mary-Carson Stiff, director of Wetlands Watch.
“We won't know for certain until we're in the future, but it is so important that the city and the Corps don’t underestimate risk, because this is a giant investment and we need to make sure that the investment is one that's going to be long-lasting.”
The surge barrier is part of the city’s larger Coastal Storm Risk Management project with the Army Corps, the same federal program that led to Norfolk’s planned floodwall. Virginia Beach is currently in the midst of a $13.5 million, five-year feasibility study.
The Corps asked city officials to choose one actionable element to focus on while the study progresses. A few months ago, Virginia Beach City Council agreed to advance the Lynnhaven barrier. It has not yet been designed or funded.
As currently proposed, the barrier would include three sets of floodgates just north of the Lesner Bridge. They would usually remain open and allow boat traffic to pass through, but close ahead of storms projected to reach an established trigger level.
Stiff said one of her key concerns is how often the city would close those gates.
The health of the Lynnhaven River relies on “flushing,” or the exchange of water flowing in and out of the Chesapeake Bay. The constant mixing helps flush out contaminants. (That’s why the northern parts of the river, closer to the mouth of the bay, tend to be cleaner than the southern reaches.)
Closing the tide gates cuts off the flow, “increasing the opportunity for bacteria to grow, for disease to take hold and for water quality to suffer,” Stiff said.
“There is so much economy that is attached to the Lynnhaven, and all of these natural ecosystems are already at a delicate balance,” she said. “So many efforts have been spearheaded to bring the river back into good health. What you're doing is putting all of that work at risk.”
Stiff said planning and analysis about the impact of gate closures needs to reflect conditions in the future, not just today. Local governments are expected to close these gates during especially high tides – and those will happen more often as sea levels rise, not just during major storms.
If officials don’t design the project with that in mind, it could underestimate maintenance costs and pollution impacts, she said.
Surge barriers also do not help communities with flooding from heavy rainfall behind the gates.
Environmental groups voiced similar concerns in Norfolk several years ago about planned surge barriers, the biggest of which will be at the mouth of the Lafayette River.
In that case, officials had already completed an environmental analysis using a low estimate of annual tide gate closures, and later agreed to update it after pushback from environmental groups.
In Virginia Beach, the nonprofits are trying to voice the issues early, so they can be adequately studied at the outset and avoid similar yearslong delays, Stiff said.
To get additional expertise, the coalition hired Biohabitats, an environmental consultant.
The company’s analysis outlined potential impacts a surge barrier could have on the complex dynamics of the river, such as changes to sediments that could increase the need for dredging and nutrient pollution buildup affecting marine life and aquaculture.
Morgan Butler, a Charlottesville-based senior attorney with the Southern Environmental Law Center, said another focus is highlighting opportunities for nature-based solutions in the Lynnhaven area.
That includes strategies such as expanding wetlands, oyster reefs and maritime forests that can naturally buffer flooding and erosion while benefiting the ecosystem.
“The planet has developed in a way where the landscape itself has been able to address flooding,” Butler said. “These features, if we leave them intact or really enhance them, have the ability to serve their natural functions and absorb flood water.”
Nature-based projects can complement, not replace, needed “hard infrastructure” made of concrete, he said.
“It's a balance that has to be struck,” he said, “and striking the right balance requires that we know what the impacts are going to be in these different scenarios.”
City and Corps officials could not provide comment for this story by WHRO’s deadline.
