Traffic is flowing freely again on north A1A near the Sebastian Inlet after a year and a half of construction barricades, flagmen and regular delays as the Florida Department of Transportation repaired damage caused by Hurricane Matthew in 2016.
Everything looks normal again along this very narrow stretch of the barrier island. The Indian River Lagoon sparkles in the sun on the west side of the road, ocean dunes rise to the east and the road tracks straight and smooth toward the exhilarating arch that carries northbound islanders over the inlet into Brevard County.
But hidden beneath the scenic surface are fundamental changes to the mile-plus stretch – one of the most fragile parts of the barrier island – where the $5.4 million project was completed.
Begun in June 2019 and finished this month almost on schedule, the project amounts to a major re-engineering of the barrier island nature created.
Using more than 10 million pounds of high-strength concrete reinforced with 109 tons of rebar, along with a vast expanse of heavy steel sheets, FDOT has armored the west side of the island to keep Highway A1A from washing out in a major storm and to protect other property on the island.
Designed by Miami-based Lakes Engineering Inc. and built by FDOT contractors, the mostly unseen new infrastructure is meant to withstand a 100-year storm and last until at least 2090, though parts of it will certainly be there for centuries.
Between Pelican Island National Wildlife Refuge and Sebastian Inlet State Park, the barrier island is a sandbar 300 to 400 feet wide without much elevation. Highway A1A runs blithely along the western edge, a vital lifeline and evacuation route used by 3,000 to 4,000 vehicles a day. In addition, the right of way contains water and cable lines.
In September 2016, Hurricane Matthew, the Cat 5 storm that crushed Haiti and did billions in damage in Florida, brushed by Indian River County, pushing a storm surge into the lagoon that crumbled the wide, concrete sidewalk and ate into the pavement of A1A in the area just now repaired.
Assessing the damage and looking soberly to the future, FDOT decided some serious reinforcement was needed along the narrow, exposed stretch of island.
The central feature of the coastal armor is a wall of sheet pilings – heavy corrugated steel sections driven 9.5 feet into the ground, making them resistant to undermining.
The thick, interlocking steel plates stick up 3.5 feet above ground. In some sections of the project that protruding metal is capped with a 2-foot, 8-inch by 2-foot steel-reinforced concrete beam, with an 8-foot-wide sidewalk poured behind the cap.
But in a long section at the north end of the job, the concrete that caps and backs the steel seawall is a massive 3-foot-thick by 10-foot-wide monolith that also serves as a sidewalk.
The final element of the new coastline is a sloping bank of rip rap – rough chunks of rock that vary in size from a foot to 3 feet in diameter – that’s packed in against the concrete cap and angles down into the water.
The rock serves to absorb and dissipate the force of waves, tides and storm surges before they reach the immovable engineering.
An FDOT spokesman says the job was done within a tight spatial framework.
“Along the west side of State Road A1A, there are FPL power lines and environmentally sensitive waters,” FDOT District Four Communications Manager Guillermo Canedo wrote in an email to Vero Beach 32963. “The project team was able to successfully produce a design that avoided the FPL lines, kept the project inside of the Department’s right of way, and took the necessary steps to protect the environment.”
Besides keeping the north island’s lifeline from washing out in a hurricane, Canedo said the infrastructure is also meant “to protect the highway and shoreline from the effects of regular wave action and king tides.”
Pedestrians, cyclists and drivers cruising north and south now and decades into the future won’t notice anything special along the newly armored stretch of coast. The seawall is concealed beneath the concrete surface and the 3-foot-thick slab looks like an ordinary sidewalk.
But there is some cool engineering and awesome structural strength hidden underneath.
Meanwhile, even though commuters, work trucks and convertibles full of beachgoers now face no delays or obstructions near the Sebastian Inlet, the Florida Department of Transportation is not done with the barrier island.
On the contrary, drivers will be looking at flagmen and traffic delays for years to come as critical infrastructure is repaired and replaced.
A $6.7 million widening and repaving project continues along a nearly 7-mile stretch of A1A in Indian River Shores, reducing traffic at times to a single lane used alternately by north- and southbound vehicles, and repair of the 17th Street Bridge, which has been deemed “structurally deficient” by the state, begins this week.
A little further off in the future, FDOT will replace the bridges at both ends of the island.
The 60-year-old drawbridge that connects the island to the mainland in Fort Pierce is scheduled for replacement beginning in March 2022, with completion in early 2026, at a cost of $70 million, according the FDOT sources.
As soon as that job is done, the Highway Department plans to replace the steeply arched bridge over the Sebastian Inlet. Design work will start next year, with construction beginning in early 2026. Completion of the $50 million structure is slated for mid-2029.