Sediment Pump-Out Areas and Conveyance Corridors

1.6Sediment Pump-Out Areas and Conveyance Corridors

The East Timbalier Pump-Out Area selected for conveyance of the sand from the hopper dredges or scow barges to East Timbalier Island Restoration Area is located in Federal waters approximately 3.3 NM south of the Island. The combination of sailing distances and discharge pipeline lengths from the Ship Shoal and South Pelto Borrow Areas to the Restoration Area are approximately 23 NM and 20 NM, respectively. The East Timbalier Pump-Out Area is designated for direct pump-out only. No bottom dumping from hopper dredges or scow barges and re-suspension of sediment by cutterhead dredge will be allowed in this pump-out area. The East Timbalier Conveyance Corridor extends ~3.3 NM from the north end of the East Timbalier Pump-Out Area, north to the existing shoreline on the western end of the Island. The width of the East Timbalier Conveyance Corridor is 600 feet. A plan view of the East Timbalier Pump-Out Area and Conveyance Corridor is presented in Figure 2-13.

The West Belle Pump-Out Area selected for conveyance of the sand from the hopper dredges or scow barges to the West Belle Headland Restoration Area is located in State waters approximately 2.4 NM south of the Headland. The sailing distances from the Ship Shoal and South Pelto Borrow Areas to the Restoration Area are approximately 26 NM and 23 NM, respectively. This area was previously permitted in 2010 (MVN-2010-01801-WOO, P20100293) as a borrow area for the West Belle Pass Barrier Headland Restoration Project (TE-52). The West Belle Conveyance Corridor extends from the north end of the West Belle Pump-Out Area, north to the existing shoreline on the western end of the Headland. The width of the West Belle Conveyance Corridor is approximately 300 feet. The West Belle Conveyance Corridor corresponds to the previously permitted corridor for the TE-52 project and the conveyance corridor is also used for the West Belle Marsh Borrow Area. A plan view of the West Belle Pump-Out Area and Conveyance Corridor is presented in Figure 2-14.

The East Timbalier Marsh Conveyance Corridor was designed to convey mixed sediments from the East Timbalier Marsh Borrow Area to both of the Restoration Areas (Figure 2-15). The East Timbalier Marsh Conveyance Corridor to the East Timbalier Island Restoration Area extends from the northeast end of the East Timbalier Marsh Borrow Area, east to the intersection with the East Timbalier Conveyance Corridor. The width of the corridor is approximately 600 feet. The East Timbalier Marsh Conveyance Corridor also connects to the West Belle Headland Restoration Area extending from the northeast end of the East Timbalier Marsh Borrow Area, east past East Timbalier Island, and then north to the existing shoreline on the western end of the Headland. The width of the conveyance corridor varies from approximately 400 feet to 600 feet. A plan view of the East Timbalier Marsh Conveyance Corridor is presented in Figure 2-15.