Posted on June 12, 2024
Notice is given to prospective Bidders that The Nature Conservancy (TNC) intends to advertise for bids by qualified Contractors to construct the “The Lower Perdido Islands Restoration Project.” The following information is provided for consideration and general planning by prospective Bidders; however, TNC reserves the right to change quantities and project features as may be necessary to address site conditions at the time of advertising.
The successful Bidder will provide the dredge and support vessels, labor, equipment, supplies and all other materials and submittals to perform all operations for (1) excavating, transporting, placing dressing and grading sand fill from nearshore borrow areas; (2) constructing nearshore, segmented rock (graded rip rap) revetment; (3) vegetative planting on constructed dune and marsh features; (4) sand fence installation.
The project sites are Robinson and Walker Islands in the Lower Perdido Bay. There are two nearby borrow areas permitted for the project and geotechnical data shows predominantly fine sand. The project will build a dune feature along the West and East sides of Robinson Island and a rock revetment at the Northeast corner. On Walker Island high marsh areas and upland fill will be built at the East and West ends. Vegetative planting and sand fencing will be placed on both islands. The presently estimated quantities include: sand to be excavated and placed is approximately 216,000cubic yards, tonnage of rock to be placed for construction of the revetment is approximately 2,500 tons, and a combined total of198,000 plants to be installed between the two islands.
This project is expected to be completed with a 12-16 inch cutter suction dredge and will require the ability to transport heavy equipment out to the islands to construct the various fill features. This is an environmentally sensitive project as the islands have large areas of seagrass around them; all hydraulic discharges will require silt screening and training dikes to prevent damage to existing vegetation. Existing depth in the borrow areas is 3 – 8feet with dig depths down to 11 – 15feet. Distance from fill areas to center of borrow areas is 1,500-3,500 feet Prospective Bidders are alerted to the existing shallow water depths surrounding the fill sites.
The bid process will commence in summer of 2024 with construction slated to begin Q4 of 2024.
To ensure that all prospective Bidders are treated equitably, any questions and/or requests for further information shall be submitted in writing to: Mike Huebsch, Moffatt & Nichol, Inc.
