Sealevel Construction completes the Bayou Chene Flood Control Structure, providing flood protection to six south Louisiana parish communities.
President of Sealevel Construction Richard Roth said, “The Bayou Chene project was the largest job we’ve completed to date in terms of size and contract value. All I can say is how proud I am of our team for their commitment to safety and construction excellence, and I look forward to taking on our next biggest project.”
Engineers and coastal representatives deem this flood control structure to be one of the largest of its kind in the United States, spanning approximately 1,050 linear feet across the channel in its closed position.
Working closely with APTIM and the project owner, St. Mary Levee District, the Sealevel team self-performed about 99% of the work including:
• Installation of floodwalls consisting of steel sheet piles and associated plumb and battered pipe piles of various sizes
• Construction of earthen levees
• Installation of landing piles
• Installation of cut-off wall
• Electrical tie-ins
Sealevel’s fabrication division, Specks Fabrication and Cutting, also performed their largest fabrication project to date with the flood control structure’s jacket receiving structures, which both stand at 40’(W) x 173’ (L) x 36’(H). The jackets were fabricated, sandblasted and painted in five months at Sealevel’s Houma-based marine affiliate company, Eagle Drydock and Marine Services.
Jacob Rahm, Fabrication Division Manager, said, “This job was a massive undertaking and a big first for our team. I am very impressed with how well our different divisions collaborated to make this portion of the project a success.”
Once complete, Sealevel worked with their heavy lift subcontractor to transport and install the jackets. Sealevel’s marine team secured the jackets by driving (16) 90-inch-diameter piles up to 165 feet in length.
Sealevel’s fabrication division also fabricated the walkways, handrails, sluice gate frames and pipe pile cap plates for the project’s flood wall portion of the project.
Following the floodwalls’ construction, Sealevel installed the last major component of the project: the automated barge gate. Fabricated and delivered by Bollinger Shipyards, the floodgate stands at 75-feet tall and 446-feet long, which is longer than a football field. Once positioned, Sealevel drove the pivot pile, connecting the barge gate to the floodwall. In its open position, the barge gate sits on landing piles, and in its closed position, it seals on a cut off wall and sits on 138 pipe piles. The gate’s unique design also allows it to sink 24 feet below the water’s surface and extend up to 10 feet while closed during high water levels. Additionally, the gate’s flap valves help equalize the water pressure on the protected and unprotected sides of the structure. The delivery, installation and testing of the gate was all completed within one work day.
Rodrigue’s Electrical Service, a Sealevel-affiliated company, then worked to complete the electrical and mechanical tie-ins, while the Sealevel team placed rip rap along the levee banks and completed other associated tasks.
Justin Lane, Sealevel’s Municipal Division Manager, emphasized how pleased he was with their team’s performance. “This project came with its own set of unique challenges, particularly with the high volume of marine traffic. The coordination between our site team, USCG and the mariners was vital to performing this project safely and with minimal impact to the marine industry. Our crews deserve a big congratulations for completing this long overdue and important project for the local area.”
Sealevel completed the multi-phased project with zero lost-time incidents and within requirements provided by the owner.
Now situated across Bayou Chene, the two-year, $80 million structure will combat backwater flooding from the Atchafalaya River. It will help preserve the homes and businesses of approximately 30,000 residents in portions of St. Mary, Lafourche, Terrebonne, Assumption, St. Martin and Iberville Parishes.
Before the permanent structure, government officials would employ local marine businesses to temporarily sink a barge in the canal during seasons of anticipated flooding. Since 2011, they sunk the barge three times, costing millions of dollars each time. The new structure will eliminate the use of the temporary barge and will also shed several days from the project schedule. Government officials noted that while it generally took about 10 days to sink the temporary barge, it will now only take about 10 hours to sink the permanent floodgate.
The Bayou Chene Flood Control Structure’s official ribbon cutting was held on April 29th, 2022, celebrating the culmination of 11 years of planning and securing funds. The project was funded by the Gulf of Mexico Energy Security Act(GOMESA) through an investment by Coastal Protection and Restoration Authority (CPRA).
Michael Brocato, St. Mary Levee District’s Operations Manager and project representative, said “Sealevel has been fantastic to work with on the Bayou Chene Flood Control Structure. They have proven their ability to adapt and think outside of the box on different issues for such a complex project. They are definitely experts in many aspects of construction.”