West Belle Headland Restoration Area and Feeder Beach

1.4.2West Belle Headland Restoration Area and Feeder Beach

The West Belle Headland beach and dune features involves placement of approximately 2.2 MCY of sand to create both beach and dune habitat. The dune will be constructed at a target elevation of +7.5 ft NAVD88, with fore- and back-slopes of 1V:25H and a typical width of 100 ft at the crest, Figure 2-5. The target elevation of the beach will be +5.0 ft NAVD88, with a slope of 1:25 from the beach berm crest extending seaward to the intersection with the existing grade, and a width of 290 ft. Assuming a 1.3:1 cut to fill ratio and being conservative in the Preliminary Design Phase, the recommended cut volume from Ship Shoal and/or South Pelto Borrow Area requirements for the sand source were calculated at 2.9 MCY.

The West Belle Headland marsh feature would also extend approximately 10,000 linear feet westward from the existing TE-52 Project, north of the beach and dune, and involves placement of approximately 1.3 MCY of mixed sediments (sand, silt and clay) to create intertidal marsh habitat. The marsh platform target elevation is +3.0 ft NAVD88 with a minimum width of 1,145 ft. Containment dikes will be constructed from sediment excavated in situ. The marsh containment dike dimensions are +5.3 ft NAVD88 elevation, 10 ft crest width, with 1V:10H side slopes. Primary (interior) and secondary (exterior) containment dike borrow channels are proposed as the sources of in situ sediment for dike construction (See Figures 2-4 and 2-5). Assuming a 1.6:1 cut to fill ratio and being conservative in the Preliminary Design Phase, the recommended cut volume from the West Belle Marsh Borrow Area requirements for the mixed sediments source is approximately 2.1 MCY.

In addition, a Feeder Beach would be constructed along West Belle Headland extending approximately 4,000 linear feet from the west jetty to provide sediment which would nourish the remaining shoreline, Figure 2-6. The modeling effort highlighted a vulnerable area within the West Belle Headland that would benefit significantly from coarser sand nourishment and result in a more robust overall restoration template for the area. The 68 acre Feeder Beach would be constructed to an elevation of +1.0 ft NAVD88, with a length of approximately 4,000 linear feet, a width ranging from 420 to 920 ft, and a seaward slope of 1V:25H, Figure 2-7. The volume of sand from Ship Shoal and/or South Pelto Borrow Area required to construct the Feeder Beach feature would be approximately 0.41 MCY. Assuming a 1.3:1 cut to fill ratio and being conservative in the Preliminary Design Phase, the recommended cut volume requirements for the sand source were calculated at 0.53 MCY.