Sanibel Causeway Emergency Repairs Phased Design-Build (PDB)

In the aftermath of Hurricane Ian, the Sanibel Causeway sustained damage to such an extent that it was impassible by land. The two islands that form part of the Causeway eroded through the force of the hurricane’s storm surge and recession. The erosion of the two islands left gaps between the remaining roadway segments and the bridge approaches, which are supported by MSE walls, and experienced failures at multiple locations. Access to the Sanibel Islands was limited to air and water transportation, and left residents without many key services. It took 15 days to get initial emergency access to the causeway.

The first phase of the project restored access to Sanibel Island through emergency repairs. KCA teamed with Superior-de Moya JV and Hardesty & Hanover (H&H) to provide a solution for emergency restoration of the Causeway. Through round-the-clock efforts, Superior-de Moya JV placed embankment on the islands and bridge approaches using a combination of dredged material and off-site fill. This effort restored access to Sanibel Island by land to the appreciation of the traveling public. During this phase, KCA provided engineering input to the contractor for recommended emergency repairs. The KCA team was on-site daily to review the state of the repairs. The next phase involved armoring of the repairs completed to reopen access to the island. This included steel sheet pile wall installation along critical retaining wall failures to ensure stability of the previous repairs, which were completed. The stability of the retaining walls and slopes is critical, especially in this location with heavy tidal influence. KCA and H&H provided structural analysis and retaining wall designs for this unique construction. The design team completed structural analysis and submittals in a matter of weeks, rather than the typical design phase, which can take months.

The final phase included permanent repairs to all the islands, including additional retaining walls around the tips of the island to protect the bridge approaches and buried retaining walls parallel to the shoulders of the roadway to prevent washouts within the islands. These repairs will protect the Causeway from sustaining the severe level of damage caused by Hurricane Ian, and will allow access to the island to be restored in a much quicker fashion.

KCA also completed permitting through several agencies, with time being a critical factor to begin and complete construction in a restricted timeframe. This included environmental surveys, preliminary engineering analysis and estimates, and many coordination meetings with the agencies.

The design and construction team of Superior-de Moya JV, H&H, and KCA worked together to reopen the Causeway to the public in a time of critical need, and the ever-evolving design and construction solutions adapted to the continuous investigation of the failed Sanibel Causeway.

The $328 million project has won several awards including the 2023 America’s Transportation Award for Quality of Life/Community Development Medium Project Group by AASHTO; 2025 DBIA Florida Region Project of the Year Award, Transportation/Roadway Category; 2025 Engineering News-Record (ENR) Texas and Southeast Region Best Project, Highway/Bridge Category; and 2024 Project of the Year Award, American Society of Civil Engineers (ASCE) Florida Section.