May 31, 2016: Holly Carpenter, who is the Project Manager with the USACE, came to speak to our Rotary Club about their current project to study and provide the design for the Charleston harbor shipping channel deepening project.
Currently, the channel is at a depth of 45ft. As larger ships come to the Charleston Port, the channel will need to be deeper to accommodate them. The USACE is responsible for the harbor deepening and other responsibilities in the state. USACE is divided into districts. Civil Works covers various watersheds in state and is an agency under the Army. Civilians are employed but overseen by the Army mainly because of navigational issues. They have a local field office with regional HQ in Atlanta. Civil Works is responsible for: navigation, hurricane preparedness, regulatory programs, etc. In SC their projects include the maintenance of Intracoastal Waterway.
“Project 45” is responsible for deepening the main harbor channel to port terminals. Dredging the channel is small portion of entire harbor. Dredging will be at slope to prevent caving in. It will require annual maintenance which will also be under the local field office’s scope.
Analysis of coastal morphology showed minimal impact to surrounding beach erosion. The Harbor was originally dredged at 12 feet, which is the Congressional authorization requirement for any dredging. Charleston’s project was deemed to be 1 of 5 major port projects approved by President Obama. They are now requesting dredging to 52 ft. at cost of $520M. This project is currently awaiting congressional approval to deepen to 52ft.
Economics: The Port has seen 20% growth and will continue to grow.
Environmental concerns were studied under the original feasibility study and included: Water quality (dissolved oxygen), wetlands & salinity ( by deepening the channel there will be an impact to freshwater wetlands as they will see a rise in salinity), fish study (showed a minor impact)
Environmental benefits: The creation of additional rock reefs, preservation of 600+ acres of freshwater impact.
Recommended plan: The entrance channel is currently 17 miles, but going additional 3 miles to 54 ft. 52 ft. in channel and 48ft at terminals. They have identified an ocean dredge disposal site in addition to upland disposal sites like Daniel Island.
Expect $109M in annual economic impact. Feasibility Study $12M. Design phase will cost an additional $4.6M. Design phase estimated to take approximately 18-24 months. Construction 46-76 months.
— Steve Coe, Keyway Committee