City staff backs advancing Lynnhaven surge barrier as Army Corps'led early actionable element

L.J. Hanson, director of public works, told the City Council that the Army Corps of Engineers has asked the city to select one "early actionable element" from the Coastal Storm Risk Management feasibility study and advance that element to 35% design so the Corps can prepare a Class 3 cost estimate. Hanson said staff and the Corps jointly recommend the Lynnhaven inlet surge barrier, a package of gates, dune enhancements and tie'in walls intended to reduce tidal inundation inland.

Hanson said the Corps'led study, originally capped at about $3 million and a three'year schedule, was revised under the Corps' "complex" process and later expanded after a headquarters request for more robust geotechnical and cost work. "That bumped the cost up to about $13,500,000," Hanson said, and he added that the city's share of the study is roughly half, about $6,670,000. He emphasized the Corps now wants a single, advanced element to reach 35% design to increase confidence in the cost estimate before seeking congressional appropriations for design and construction.

Explaining how the gates would operate, Hanson described two outer tainter gates and a central rising sector gate at the Lynnhaven inlet that would be closed for tidal'surge events; the rising sector gate allows larger'clearance vessels to transit when open. He said closure durations vary by storm type: roughly 26 hours for hurricanes and about 45 hours for nor'easters in the Corps' preliminary analysis. "We would close the gate at low tide if we're anticipating an event where we might have 4 foot of rise," Hanson said, while cautioning the 4'foot threshold is preliminary and could change.

Hanson estimated that after the 35% design is completed and the Corps signs the chief's report in 2028, the Corps would seek construction appropriations in 2030. "It will be in the $100,000,000 plus range," he said, adding he could not responsibly offer a precise construction cost at this stage.

Council members asked about aesthetics, notification timing, effects on navigation and outreach responsibilities. Hanson said the Corps has led public engagement to date and that city staff will coordinate to increase outreach if council concurs. He also said staff will work with pilot and maritime associations on navigation impacts and will program the city's 35% design share into the 2028 budget planning cycle. "We are the nonfederal sponsor," Hanson said; "we'll be the ones responsible for operating this after it's completed."

Council members generally signaled support for allowing the Corps to proceed to 35% design for the Lynnhaven element, while several urged immediate, clear public engagement to address misinformation and local concerns. If council concurs, Hanson said the next steps are to complete 35% design for the selected element, plan local matching funds for design (estimated in the $10'$15 million range when the 35% design is prepared), and explore alternate authorities for advancing other elements if needed.

The choice to advance a single element does not stop the overall study, Hanson said; other planning districts will remain part of the feasibility report but would advance on separate timelines or funding paths. He asked council to authorize either the mayor or city manager to sign a letter confirming the city's concurrence so the Corps can proceed.