Mississippi River Closed - Corps of Engineers Responding
August 13, St. Louis – The U.S. Coast Guard has closed the Mississippi River at river mile 257.1, near Hamburg, Ill., about 15 miles above Winfield, Mo. The closure follows the grounding of a 15-barge tow at that location. Possible problems with the navigation channel are being investigated at other locations at this time as well. The U.S. Army Corps of Engineers in St. Louis is preparing the District’s dustpan dredge, Motor Vessel Potter, to get underway to remove deposits of sediment that have obstructed navigation. She was originally scheduled to start work later in August but is now expected to depart its berth at the St. Louis District’s Service Base by Friday. She should arrive at the grounding location and be ready to go to work there by Saturday. River engineers explain that during recent flooding and high water events, large amounts of sediment – sand and soil eroded from farm fields – were scoured and carried into the river. As the river fell rapidly in recent days, the energy that scoured and carried the sediment load quickly diminished, allowing the material to drop out of suspension and to the bottom of the river. This has reduced the navigation channel’s depth. The Corps of Engineers is charged with maintaining at least a nine foot deep, 300 foot wide channel. Those dimensions support safe movement of 15-barge tows, the largest that normally operate on the section of the river with locks and dams between Minneapolis/St. Paul and as far south as Granite City, Ill. Corps and contract survey vessels, including the St. Louis District’s Motor Vessel Pathfinder, are currently surveying the river to accurately map the bottom contour. The Corps is also exploring temporarily raising pool elevation by reducing the flow at Dam 25 near Winfield while work proceeds to help remove the remaining grounded barges. But it will still require dredging to restore a safe and efficient channel once the barges are removed. Dredging may be needed at other locations as well. During the closure, conference calls between the National Weather Service, the Coast Guard, the Corps of Engineers and navigation representatives are being conducted to coordinate actions to best ensure safe and dependable navigation is restored as rapidly as possible. Commercial navigation on the Mississippi River moves large quantities of bulk commodities, including 60 percent of the nation’s agricultural commodities slated for overseas export from the port of New Orleans. |
