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Key Insights:
Quick Facts:
- Name: Rockefeller Refuge Gulf Shoreline Stabilization
- Location: Cameron and Vermillion Parishes, Louisiana
- Client: Louisiana Coastal Protection and Restoration Authority
- Size: 26.5-mile stretch, with a focus on 9.2 miles
Challenge: To stop severe erosion along Louisiana’s Gulf coastline, particularly in soft subsurface areas where traditional stone solutions failed.
How Arcosa Helped
- Our Solution: Provided lightweight aggregate, encapsulated in geotextile bags, to create breakwaters along the shoreline.
- Why Lightweight Works: The ceramic aggregate resists sinking in soft soils, maintains stability, and is easily encapsulated for protection from water currents and wave action.
Final Results
- Successfully halted coastal erosion along the designated 9.2-mile stretch, with the breakwaters meeting all stability and environmental impact criteria.
Key Quote
“Only the lightweight aggregate core breakwater, which lost only 3 ft of land, met all our criteria.” — Brett Geesey, P.E., Coastal Project Manager, HDR Engineering
Context:
- Considerations: Encapsulated lightweight aggregate provided an environmentally sustainable solution where previous materials failed to stabilize.
- Lesson to Learn: Lightweight aggregate, when used with geotextile bags, offers a durable solution for coastal protection in challenging conditions.
Explore Further
Civil Engineering Magazine Highlights LWA Breakwaters
In January 2021, Civil Engineering, the magazine of the American Society of Civil Engineers (ASCE), published a thorough article about the massive land-saving project along the 26.5 mile section – with an emphasis on a specific 9.2 mile stretch of marshland – bordering the Gulf of Mexico in Cameron and Vermillion Parishes.
The article, titled “Breakwaters Aim to Halt Ongoing Erosion at Coastal Refuge”, was written by Robert L. Reid, the magazine’s senior editor and features manager. Of particular note were comments from Brett Geesey, P.E., Coastal Project Manager at HDR Engineering, who says:
The article explains that HDR Engineering previously used lightweight aggregate concrete (LWAC) breakwaters in Louisiana, but only in interior water systems — never along an exposed gulf shoreline.
Trusting the Process of Creating the Best Lightweight Product
Arcosa’s encapsulated lightweight aggregate played a crucial role in preserving Louisiana’s valuable coastline. While the Civil Engineering article provides a detailed read, Arcosa’s Bill Wolfe explains exactly how the company’s lightweight aggregate contributes to the success of coastal breakwaters.
Wolfe describes the process: “The clay used to create our lightweight aggregate is mined onsite at Arcosa’s production facilities,” he explains. “It’s fired in a rotary kiln to about 2000°F, reaching a near-molten state similar to lava. During this phase, the material releases gases, forming tiny air voids within the clay. Once cooled, it’s no longer clay but a durable ceramic aggregate ideal for coastal applications.”
Winning Combination: Arcosa Lightweight and Industrial Fab
Arcosa Lightweight and Industrial Fabrics have partnered for years on coastal preservation projects, refining their products for durability and longevity. The process of creating breakwaters has become seamless and is performed directly on-site.
The lightweight aggregate is placed in geotextile bags by the contractor on site, sealed, and positioned along the shoreline, then capped with riprap. These breakwaters have proven both environmentally friendly and highly resilient, withstanding storms and tidal forces for nearly two decades.
Trial and Error and the Path to Encapsulated Lightweight
Wolfe notes that the geotextile bags are essential for keeping the material in place, which is especially critical in soft subsurface areas like Rockefeller Refuge. Previous efforts using traditional stone failed as the stone would simply sink into the mud, requiring constant replacement and escalating costs.
“Ordinary stone, well it sinks in the mud basically,” Wolfe explains. “It settles. Sometimes it would sink so fast that they could never break the water line. They just kept adding stone, and it would just keep sinking.”
Hope for the Future
The combination of Arcosa’s lightweight aggregate and Industrial Fabrics’ geotextile bags has significantly benefited Louisiana’s coastline. Since its creation in 1920, the Rockefeller Wildlife Refuge has lost 15,000 acres, with more than 300 feet of land disappearing in recent years. The need for effective solutions has grown, and in 2000, the Louisiana Coastal Protection and Restoration Authority and the National Marine Fisheries Service launched the Rockefeller Refuge Gulf Shoreline Stabilization Project.
The focus was on a severely eroded 9.2-mile stretch of the refuge in Cameron Parish, designated as ME-18 under the Coastal Wetlands Planning, Protection, and Restoration Act. This project, valued at over $33 million, successfully halted the erosion that had caused severe land loss.
Arcosa Lightweight is committed to supporting projects that preserve our coastlines, demonstrating how effective engineering and innovative products can help conserve these vital resources.
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