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Title: Charleston Harbor, Charleston, South Carolina : Final Feasibility Report with Environmental Assessment
Authors: United States. Army. Corps of Engineers. Charleston District.
Keywords: Charleston Harbor (S.C.)
Channels (Hydraulic engineering)
Environmental protection
Environmental management
Publisher: United States. Army. Corps of Engineers. Charleston District.
Abstract: This report has been prepared under authority of resolutions adopted by the Senate Committee on Environment and Public Works and the House Committee on Public Works and Transportation on 27 March 1990 and 1 August 1990, respectively. These resolutions authorized the Corps of Engineers to conduct a review of the reports on Charleston Harbor, South Carolina with a view of determining whether any modifications to the existing project are advisable at this time with particular emphasis on deepening and widening. Planning, Engineering and Design studies will be continued under this authority. Charleston Harbor is the largest and most important seaport in South Carolina and is ranked as the second largest container port on the East Coast and Gulf Coast of the United States. The harbor is a natural tidal estuary formed by the confluence of the Cooper, Ashley and Wando Rivers and located about midway of the South Carolina coastline, being approximately 140 statute miles southwest of the entrance to Cape Fear River, North Carolina, and 75 statute miles northeast of the Savannah River, Georgia. The authorized Charleston Harbor Project was essentially completed in August 1991 with the exception of the Wando River Extension (August 1994) and Shipyard River Entrance (June 1996). The authorized project provides for a 42 foot deep by 1,000 foot wide entrance channel extending for approximately 11 miles from the 42 foot contour to the mouth of the harbor; thence, 40 foot deep by 600 foot wide (generally) to Goose Creek on the Cooper River a distance of 16 miles; a 2.1 mile long 40 foot deep channel in the Wando River extending from the Cooper River to the Wando Terminal; 0.7 miles of improvements in Shipyard River consisting of a 38 foot deep by 300-foot wide entrance channel, and a 700 foot diameter Turning Basin A, a 30 foot deep by 200 foot upper channel and a 500 foot diameter Turning Basin B; 2.8 miles of improvements in Town Creek 40 foot deep by various widths; an anchorage basin at the junction of Ashley and Cooper Rivers 35 foot deep approximately 2,200 feet by 5,200 feet; three turning basins 1,400 feet in diameter in Town Creek, Wando River and at the head of the project. Features that are authorized but not constructed include: a 1,000 foot Turning Basin A in Shipyard River and deepening and widening the upper channel to 38 feet deep by 250 feet wide; widening Turning Basin B to 1,000 feet, this feature was determined not to be economically justified; and deepening and enlarging the anchorage basin to 40 feet. Existing channel depths, widths, and alignments constrain the ability of vessels to utilize the port to their design capacity, increase transit time due to limited ability to pass except at designated locations, and/or present hazardous conditions. Vessels with deeper draft will be able to take advantage of a deeper channel and reduce transportation costs from tidal delays. Additional transportation savings will result from improved passing areas and alignments. Benefits from improved depths of 41 to 46 feet were considered in this study. The 45-foot channel depth was identified as the National Economic Development plan and is the recommended plan. The recommended plan provides a 16.3 mile 47 foot by 800 foot wide entrance channel with continued maintenance of the authorized 42 foot by 1,000 foot channel, 45 foot interior channels, and turning basins, with no improvement in width unless otherwise noted, and a realigned channel in the Shutes/Folly Reach of the lower harbor, and reduction of the Town Creek Channel from the Cooper River bridges to Myers Bend to a 16 foot by 250 foot channel. The Daniel Island Reach channel will be widened to 875 feet beginning at the conjunction of Myers Bend tapering to a width of 600 feet at Daniel Island Bend. Features for construction to coincide with the completion of the proposed Daniel Island Terminal are: construction of an additional contraction dike located just north of Shipyard River and the Navy degaussing pier, restoration of the existing training dikes to their original condition when the third is constructed, removal of existing contraction dike on Daniel Island, and construction of a turning basin 1,400 feet by 1,400 ft. Based on the construction schedule, the total initial project cost is estimated to be $116,639,000. Of this amount $27,020,000 would be the initial sponsor cost share of the general navigation features for 25 percent of the first cost. The sponsor is responsible for 100 percent of the dredging cost associated with deepening all berthing areas to the project depth in the amount of $6,012,000. The initial Federal share of the general navigation features of first cost is $81,062,000. The sponsor shall pay an additional 10 percent of the cost of the general navigation features of the project in cash over a period not to exceed 30 years, at an interest rate determined pursuant to section 106 of WRDA 86. The value of lands, easements, rights-of-way, relocations, and dredged material disposal areas shall be credited toward the additional 10 percent. This credited amount is estimated to be $2,466,000 bringing the total initial sponsor share of first cost to $43,841,000 with total Federal share being $72,798,000. The South Carolina State Ports Authority is the project sponsor. They support the plan recommended in this report.
Description: Feasibility Report with Environmental Assessment
Rights: Approved for Public Release; Distribution is Unlimited
Size: 563 pages / 19.52 MB
Types of Materials: PDF/A
Appears in Collections:Environmental Documents

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