NAME OF APPLICANT: Greater Lafourche Port Commission c/o Mohan Menon of GIS Engineering, LLC., 450 Laurel Street, STE 1500, Baton Rouge, LA 70801.
LOCATION OF WORK: In Belle Pass, Sections 22, 24, 25, 26, and 28, Township 23S, Range 22E, just south of Port Fourchon, Louisiana, in Lafourche Parish, within the Terrebonne Basin in hydrologic unit (HUC 08090301), as shown on the attached drawings (Latitude 29.103333 N, Longitude -90.206667 W).
CHARACTER OF WORK: The applicant has requested Department of the Army authorization to clear, grade, excavate, and deposit fill and dredged material to construct and maintain a slip on Fourchon Island for the Fourchon Island Development Project (Phase 1) to include a 1,480-foot wide slip at a 2,600-foot depth, an 8,227 LF bulkhead, approx. 15.7 acres of containment levees, access roadways including a 1,590 linear-foot bridge spanning a private canal, and proposed beneficial spoil placement with appurtenant discharge pipeline. Approximately 5,017657.9 cubic yards would be dredged to create the slip, of which approx. 2,476,770.3 cubic yards will be used as fill material in approx. 198.1 acres around the slip for development of the port facility, approx. 169,972.9 cubic yards will be redistributed to backfill borrow ditches for the containment levees, and the remainder will be deposited in adjacent open waters to create saline marsh habitat. Approx. 6,219.2 cubic yards of riprap will be utilized for the bridge and erosion control, and approx. 14,600 cubic yards earthen fill from off-site, approx. 50,300 cubic yards of crushed limestone, and 9,000 additional cubic yards of asphalt will be deposited for the roadways. A Preliminary analysis has determined that the proposed project would directly impact approx. 875.3 acres of jurisdictional wetlands and waters including approx. 4.14 acres of traditionally navigable waters for marine workspaces.
MITIGATION: The applicant has designed the project to avoid and minimize direct and secondary adverse impacts by maximizing the dredge disposal pipeline’s corridor placement in open water as opposed to atop wetlands wherever possible and by designing retention berms to hold redeposited fill material in place to prevent erosion and sediment transport. Any further reduction would limit usage of the property and therefore, function, deeming the project impracticable. As compensation for unavoidable wetland impacts, the applicant proposes to utilize dredged material from the excavation of the slip to convert approx. 514 acres of open water to marsh wetlands in four designated mitigation areas. Approximately 22,812 linear feet of discharge pipe will temporarily impact approx. 26.18 acres of wetlands and waterbottoms in order to transport the dredge material to the mitigation areas and a total of approx. 11.6 acres of containment levees will be constructed for the marsh mitigation areas.