GeoEngineers’ Caillou Lake Headlands restoration project off the Louisiana coast recently won a National Recognition Award in the American Council of Engineering Companies’ (ACEC) Engineering Excellence Awards program. This is the second award the project received from ACEC. In 2019, the project also earned a Grand Award from the Louisiana ACEC chapter for its effectiveness in preserving the state’s sensitive dune and marsh habitats.
The ambitious Caillou Lake Headlands Project restored Whiskey Island, a critical barrier island along Louisiana’s Gulf Coast. Barrier islands protect vulnerable coastal ecosystems and communities from storms and waves, but Whiskey Island was slowly disappearing beneath the water. CPRA’s vision, combined with the important engineering work of Coastal Engineering Consultants (CEC) and GeoEngineers, turned an island that was on the verge succumbing to the Gulf into a fortified barrier island by creating over 600 acres of beach, dune and marsh habitat.
To date, Whiskey Island is the largest restoration project ever completed in Louisiana by volume. Contractors dredged, transported and placed approximately 10.1 million cubic yards of dredged sand on the island—enough to fill the New Orleans Super Dome twice. GeoEngineers provided geotechnical investigation and engineering services as a subconsultant to CEC in support of their designs.
Restoring Whiskey Island was a significant technical challenge. The island is a 40-minute boat trip from shore, making access difficult. Dynamic tidal forces meant rapidly changing conditions, and severe weather caused damage and delays. The team realized that the traditional soil sampling procedure of collecting and transporting soil samples from the island to the mainland would result in disturbed samples and excessive cost. To mitigate this issue, GeoEngineers suggested supplementing traditional sampling with cone penetrometer testing (CPTs). CPTs provide soil data instantly on location versus having to send samples to a lab. Including CPTs in the design process reduced the number of days on site and testing costs while providing high quality data. CPRA has recognized the effectiveness of this practice and has since included the use of CPTs in their Marsh Creation Design Guidelines.
“CPRA has had a longstanding relationship with CEC and GeoEngineers, and they proved to be the perfect fit to design Whiskey Island,” said CPRA Whiskey Island Project Manager Brad Miller. “The level of engagement and the respect that the design team gave the Whiskey Island project was remarkable. They were inclusive, collaborative and focused, and there was no question that they gave us the very best of their talents.”