Experience Informs CWPPRA Design, Construction
Breaux Act Projects Weather Storms
With powerful waves and record-setting storm surge, the hurricanes of 2005 were a tough test of Breaux Act projects across the coastal zone. But out of 123 projects studied in late 2005, only 17 need post-hurricane repairs — a testament, say coastal scientists, to the collective knowledge and experience of agencies partnered under the Coastal Wetlands Planning, Protection and Restoration Act of 1990 (CWPPRA, or the Breaux Act).
CWPPRA partners refine and improve projects’ design and construction through a process called adaptive management. “We evaluate every project carefully to determine where, how and why it worked or didn’t work,” says David Burkholder of the Louisiana Department of Natural Resources (DNR). “As we repair damaged projects and plan new ones, we apply those lessons.”
At the Marsh Island Wildlife Refuge in Iberia Parish, adaptive management helped one project survive Hurricane Rita with little significant damage.
The 2001 Marsh Island Hydrologic Restoration project (TV-14) installed rock closures in seven navigation canals to keep salt water out of marshes and closed a breach between a small lake and Vermilion Bay. Less than a year later, Hurricane Lili severely damaged three of the structures.
A rock riprap and steel sheetpile weir closes off a former oilfield canal at the eastern
end of Marsh Island. Courtesy of Louisiana Department of Wildlife and Fisheries; Stanley R. Aucoin, Louisiana Department of Natural Resources
Sections of the weir repaired following Hurricane Lili held as Hurricane Rita blasted
across the island. Courtesy of Louisiana Department of Wildlife and Fisheries; Stanley R. Aucoin, Louisiana Department of Natural Resources
“When a big slug of water hits structures like these, it flows around them at high speed, eroding the ends,” says Herb Juneau of the DNR. “So when we repaired the damage from Lili, we did more extensive paving of the ends of the canal closures to prevent future damage.”
Three years later Rita, a much more powerful storm, inundated the island with nine feet of water — yet the three repaired structures survived virtually unscathed, and the project suffered damage to just two of eight structures. “The success at Marsh Island, as well as at other projects across the coast, is the result of the design process incorporating CWPPRA’s 16 years of experience,” Burkholder says.