Crews work to rebuild the Sanibel Causeway following Hurricane Ian’s destruction in 2022.
Photo courtesy of Superior Construction

The emergency work, however, revealed deeper vulnerabilities. The original 1963‑era design relied on mechanically stabilized earth (MSE) walls and embankments that could not withstand sustained hydrostatic pressure and wave action. A full rebuild was necessary, prompting FDOT to shift the corridor into phased design‑build—its first use of the method for a catastrophic event. The permanent reconstruction was awarded to the Superior–de Moya joint venture, combining Superior’s heavy civil and marine capabilities with the de Moya Group’s coastal and structural expertise. Work began in September 2023, backed by $51.6 million in state funding approved earlier that year.

Superior Construction Area Manager Toby Mazzoni says two early decisions proved pivotal. The first was treating emergency repairs as permanent infrastructure from day one, eliminating the need to remove temporary structures later. The second was shifting from traditional MSE walls to a steel sheet-pile system with king pile technology. “The steel sheet pile system wasn’t just substituted for the MSE walls,” he says, adding it was deployed to harden the roadway and protect bridge substructures and approaches, a scope informed by the use of ADvanced CIRCulation and Simulating Waves Nearshore coastal modeling.

Photo courtesy of Superior Construction

Permanent reconstruction reached substantial completion in 105 days, meaning the full structural rebuild was finished, and the corridor was ready for traffic. Crews installed 750,000 sq ft of steel sheet pile, raised seawalls to 8 ft from 5 ft, rebuilt embankments, added underdrains and armored shorelines with 127,996 tons of stone. The roadway elevation was increased to improve storm‑surge performance, and advanced drainage systems were installed to reduce long‑term maintenance needs.

The work required careful coordination with weather, tides and marine traffic. Crews operated from barges and temporary platforms in shifting wind conditions, sequencing operations to maintain access while advancing sheet‑pile installation, shoreline armoring and roadway reconstruction. The phased design‑build approach enabled FDOT and the contractor to issue advance work packages and refine design elements as construction moved forward.

The 2024 hurricane season became the project’s first major proving ground. Completed sections withstood the direct impacts of Hurricanes Debby, Helene and Milton with minimal damage, affirming the modeling-driven decision to shift from traditional MSE walls. While unfinished areas saw washouts, the hardened features performed as intended. “During those three hurricanes, the steel sheet pile wall systems, elevated roadway profile and marine mattress scour protection all performed as intended—a real-world confirmation of the design team’s decisions,” Mazzoni says.

Photo courtesy of Superior Construction

The project also delivered ecological and community gains. In 2025, the Sanibel‑Captiva Conservation Foundation recorded the most successful nesting season for least tern seabirds on the causeway islands since the 1990s, marking the third year of a steady rebound. Black skimmer seabirds also returned, as did economic activity, with causeway traffic reaching 82% of pre‑Ian levels and overall business recovery hitting 74% by late 2025.

“This corridor is built to handle what’s coming,” Mazzoni says. “The systems we put in place are doing exactly what they were designed to do, and they’ll keep protecting this link for years to come.”