The U.S. Army Corps of Engineers (USACE) has completed an extended dredging season, and has brought equipment in for seasonal maintenance and leave for the crew. The USACE Dredge Hurley, based in Memphis, and Dredge Potter, based in St. Louis, completed dredging operations in late January.
These two dustpan dredges have been operating well beyond the normal dredge season, which usually ends in early November.
The Potter mobilized the first week of July, and has worked throughout the 300 miles of Mississippi River in St. Louis District’s area of responsibility.
After completing a highly demanding season on the Lower Mississippi River that began in April 2012, the Hurley came up river from the Corps’ Memphis District in December and worked above the confluence of the Ohio River and supporting rock pinnacle removal efforts at Thebes.
As dustpan dredges, the Hurley and Potter remove sediment to maintain the Congressionally-mandated channel depth and width. USACE dredged more than 8 million cubic yards of sediment along the Middle Mississippi River in the last six months – more than twice the amount dredged during an average, non-drought year. And yet, this was only half the amount dredged during the drought of 1988-89 when ice floes formed in the low water.
River training structures and other engineering innovations have greatly reduced dredging needs in low water. Restrictions to industry traffic were limited to safety operations during blasting and other demolition. There were no delays in traffic due to low water at Thebes this winter.
USACE will continue to monitor crossings, points on the river where the flow of water within the channel changes from one side of the riverbank to the other. The Potter will be the dredge to respond to any "just-in-time" dredging needs, should the sediment patterns change with fluctuating river levels.
Rock removal work continues at Grand Tower and Thebes as conditions permit. With recent rains, river levels have risen to a point that contractors have temporarily suspended work. Rock removal will resume as river levels fall, potentially as early as Thursday, based on current forecasts.