EPA Allows Dredging Discharge in Bayou aux Carpes
The U.S. Environmental Protection Agency on May 28 announced a decision to modify its 1985 determination prohibiting the discharge of dredged or fill material in the protected wetlands of the Bayou aux Carpes area south of New Orleans.
The decision will allow for discharges associated with construction of the Gulf Intracoastal Waterway (GIWW) West Closure Complex within the Bayou aux Carpes site as part of the proposed enhanced levee system in Jefferson Parish, La.
After Hurricanes Katrina and Rita in 2005, Congress directed the U.S. Army Corps of Engineers to enhance the existing hurricane risk reduction system that serves the west bank of the Mississippi River. As part of this upgrade, the Corps proposed to build a new levee within the Bayou aux Carpes wetlands in Jefferson Parish, where discharge of dredged or fill material has been prohibited by EPA since 1985. The GIWW West Closure Complex project is part of a much larger project that will reduce flooding risks to 250,000 people living in south Louisiana.
“Today’s decision achieves a balance between the national interest of reducing overwhelming flooding risks to the New Orleans area and critical infrastructure of south Louisiana while ensuring protection of a vital ecosystem,” said Acting EPA Regional Administrator Lawrence E. Starfield. “We are pleased that earlier this year Congress recognized the area for its uniqueness, ecological integrity, and beauty by making it part of the National Park system.”
"The Interagency Team assigned to this project engaged the navigation industry, local nongovernment organizations, and parish leadership to identify the best engineering, least damaging, and most effective risk-reduction measure for people living and working on the west bank,” said Colonel Alvin Lee, New Orleans District Commander.
The Corps’ GIWW West Closure Complex would include the construction of a concrete “T-wall” style floodwall along the boundary of the site in lieu of a levee bisecting the site in order to minimize the environmental impacts to the Bayou aux Carpes wetlands. The placement of the wall within the 100-foot by 4,200-foot perimeter corridor in the Bayou aux Carpes area, along with the commitment by the Corps to fully mitigate for the unavoidable wetlands impacts and to implement additional ecological enhancement features, provides the most practical approach from an environmental perspective while ensuring the 100-year level of risk reduction is accomplished.
The decision will provide adequate protection of the ecological integrity of the Bayou aux Carpes wetlands, according to EPA. The projected construction impacts will be limited in time and area, the unavoidable impacts will be appropriately mitigated, additional features will be developed and implemented to enhance the wetlands, and the site will be monitored and managed for any adverse changes for the life of the Corps project.