SOUTH MILLS, N.C. - Due to required maintenance, the Dismal Swamp Canal on the Atlantic Intracoastal Waterway between North Carolina and Virginia has been shut off to vessel traffic.Work crews from U.S. Facilities Inc. - the primary services contractor for Norfolk District, U.S. Army Corps of Engineers - removed two South Mills Lock canal gates last week, assisted by subcontractors W.O. Grubb Crane Rental and Chesapeake Bay Diving Inc. The $525,000 rehabilitation project is expected to take 90 days.As a result, the locks at South Mills and Deep Creek, Virginia, which cover Route 2 on the AIWW's Dismal Swamp Canal, have temporarily ceased operations."Repairs are estimated to be completed by the end of March, before the spring migration of vessels going north for the summer," said Joel Scussel, Norfolk District's Atlantic Intracoastal Waterway project manager. "There are no spare gates for locks on the Dismal Swamp Canal. This requires us to shut the canal - then remove, refurbish and replace the gates during the slower months."There are no boats in the canal now. We notified the Coast Guard, and we will not let any vessels in at South Mills Lock or Deep Creek Lock until this refurbishment is complete."Norfolk District manages and operates two sets of gates at South Mills Lock and two at Deep Creek Lock along the Dismal Swamp Canal.The Albemarle and Chesapeake Canal, encompassing Route 1 through Great Bridge Lock, will remain open 24/7, Army Corps officials said. Facility operators can be contacted on Marine Channel 13.Scussel said canal gates on the AIWW are removed and restored on a rotational basis every 15-20 years as part of a service plan to increase a lock's life span. This South Mills set - each gate measuring 17 feet by 30 feet and weighing 15 tons - was last rehabilitated in 2002."The work is necessary because any structure in the water requires restoration. Gates are one of the critical structures to the lock, and water can take a toll over time," he added. "It's among our ongoing efforts to ensure safe navigation for the vessels that use these channels."The Dismal Swamp Canal, together with the Albemarle and Chesapeake, form the historic Atlantic Intracoastal Waterway, which provides recreational boaters and commercial shippers a protected inland channel from Norfolk, Virginia, down to Key West, Florida, and north to Eastport, Maine.Questions about this project can be referred to the USACE Norfolk District Public Affairs Office at 757-201-7606.