News Stories

Construction on Ecosystem Restoration Project nears completion

USACE Mobile
Published March 23, 2017
Construction workers unload a wave attenuation device (WAD) into the water near Bayou Caddy with a barge-mounted crane. The U.S. Army Corps of Engineers, Mobile District, used the WADs as part of a living shoreline to reduce wave energy.

Construction workers unload a wave attenuation device (WAD) into the water near Bayou Caddy with a barge-mounted crane. The U.S. Army Corps of Engineers, Mobile District, used the WADs as part of a living shoreline to reduce wave energy.

Following Hurricane Katrina, the USACE restored more than 18 acres of wetlands near Waveland, Miss. under the Bayou Caddy Restoration Project. In the absence of action, continued erosion would have eventually led to a net loss of tidal marsh, estuarine habitat and productive fisheries.

Following Hurricane Katrina, the USACE restored more than 18 acres of wetlands near Waveland, Miss. under the Bayou Caddy Restoration Project. In the absence of action, continued erosion would have eventually led to a net loss of tidal marsh, estuarine habitat and productive fisheries.

Engineers from the U.S. Army Corps of Engineers, Mobile District (USACE), inspect the Bayou Caddy Ecosystem Restoration Project from a boat in the Mississippi Sound, Mar. 21. The project is expected to wrap up by the end of this month and will enhance the resiliency of the Mississippi coast.

Engineers from the U.S. Army Corps of Engineers, Mobile District (USACE), inspect the Bayou Caddy Ecosystem Restoration Project from a boat in the Mississippi Sound, Mar. 21. The project is expected to wrap up by the end of this month and will enhance the resiliency of the Mississippi coast.

In 2005, Hurricane Katrina swept away more than 18 acres of wetland in Bayou Caddy near Waveland, Miss. In the aftermath of the destruction, several studies concluded that the area was the most susceptible coastline in the country to be hit by another severe storm.

“There were a whole bunch of studies done after [Hurricane] Katrina because the two of the largest storm surges in U.S. history (Hurricane Camille in 1969 and Katrina in 2005) hit right there in Waveland,” said Susan Rees, coastal resiliency program manager for the U.S. Army Corps of Engineers, Mobile District (USACE). “Based on those studies, [it was] found that this area of the coastline was three times more likely to get hit by a severe storm than any other point in the continental U.S.”

Even without another severe storm hitting the area, the Bayou Caddy wetlands would have continued to erode due to a high wave energy concentration that is focused at that point. The erosion would have eventually led to a net loss of tidal marsh, estuarine habitat and productive fisheries.

To prevent that from happening, the Federal government authorized the USACE to execute the Bayou Caddy Ecosystem Restoration Project. The project aims to aid in the immediate recovery of the wetlands, and enhance the resiliency of the coast against future storms.

“Without those 18 acres, the other 3,000 acres of the wetlands became more vulnerable to erosion, because you lost the tip of the spear,” explained Rees. “So the first thing we had to do was restore the wetlands that were lost.”

Construction on the wetlands began in 2009 and was finished by 2013. After restoring the wetlands, USACE shifted their focus to shoreline stabilization.  

“They put in a rock, rubble-mound breakwater along the northwest section of the coast because that is where the wave energy is most intense,” said Joe Black, civil engineer for the USACE. “That gave us enough protection to utilize a living shoreline for the rest of the site.”

The living shoreline will consist of five, 300-foot rows of marine-grade bioengineered concrete wave attenuation devices (WAD). According to Black, the WADs will provide enough protection to dissipate wave energy, but will still allow water to flush in and out of the ecosystem.  

Construction for the entire project is expected to wrap up by the end of March. Upon completion, the project will not only improve the resiliency of the coast, it will also help the ecosystem in the wetlands flourish.

“In addition to the breakwater structure that you want, you also have an ecological benefit with an increased fish habitat,” Rees said. “[The WADS] are made out of a special concrete the oysters will ultimately attach to and once they become attached, they will serve as a food source for other fish.”

As construction on the project comes to a close, Black reflected on the value of using living shorelines in USACE projects. 

“It’s not something that has been done a lot, [but] it’s something that I hope to see more of moving forward,” said Black. “Traditional rock and concrete bulkheads can have environmental impacts. So we are really hoping to achieve the protection we want [with this project], while still maintaining the environment.”

The USACE will continue to monitor the site through 2022 to ensure the project is working as designed.