The New Orleans District Corps of Engineers has issued a proposal to designate an additional disposal area for the beneficial use placement of shoal material removed during routine maintenance of the federal navigation project Barataria Bay Waterway Louisiana.
The proposal involves modification of the previously-approved disposal plan and the placement of dredged material into navigable waters which requires issuance of a public notice.
The Barataria Bay Waterway consists of a navigation channel between the Gulf Intracoastal Waterway at Barataria Louisiana to the Gulf of Mexico south of Grand Isle with a project dept of 12 feet from mile 36.5 to mile 0.0 and a depth of –15 feet MLG from mile 0.0 to the –15-foot depth contour of the Gulf of Mexico. The channel is 125 feet wide from mile 36.5 to mile =1.26 and 250 wide from mile –1.26 to the –15-foot contour. The channel is approximately 37 miles long. The project provides for a westerly channel extension from the main channel extending 4.3 miles into Bayou Rigaud along the north shore of Grand Isle.
In 1995 the New Orleans District designated a 575-acre disposal area on and adjacent to Grand Terre Island for island restoration. This area was nearly filled to capacity during maintenance of the Barataria Waterway bar channel in fiscal years 1996 and 1999.
The District proposes to designate an 81-acre area adjacent to and parallel to Grand Terre Island for placement of shoal material removed during routine maintenance to be used for beach nourishment. The area would be composed of approximately 27 acres of beach habitat and 54 acres of water bottom habitat adjacent to and parallel to Grand Terrre Island along the Gulf of Mexico shoreline. The discharge point would be located on the beach and the dredged material placed unconfined into the surf zone. It is anticipated that between maintenance events dredged material placed in this area would be dispersed by waves and storm events onto the island into the littoral drift and offshore. All dredged material would be placed in the area in a manner conducive to barrier island habitat development.
Approximately 700000 cubic yards of material would be removed from the Barataria Waterway bar channel segment every two to six years. The property adjacent to the area includes intermediate to saline marsh upland disposal areas barrier islands and open waters of Barataria Bay and the gulf of Mexico. No accurate estimate can be given to the amounts and /or frequency of dredging required to maintain non-federal facilities in the vicinity of the project.
The New Orleans District will prepare an environmental assessment addressing the impacts of the designation and use of this area and will provide the Coastal Management Division of the Louisiana Department of Natural Resources a consistency determination for the proposed action. The District will also follow state water quality guidelines and federal guidelines and will consult the U.S. Fish and Wildlife Service regarding impact on threatened or endangered species and on fish habitat in the Gulf of Mexico.