Boats carrying cargo are being allowed to move along the Mississippi River after traffic was halted for a day over the risk that the swollen waterway would break its banks and flood huge areas of farmland in the lower delta.
The Coast Guard closed a 24km section of the river around Natchez - which is north of New Orleans - for much of Tuesday as waters threatened to flow over vital flood defences. It meant shipping could not head towards the Gulf of Mexico or return north after delivering freight there.
Late on Tuesday officials began allowing the boats to pass one at a time but said they must travel as slowly as possible so that the wakes they create would not increase the pressure on the defences.
The barges carry iron, coal, timber, steel and more than half of US grain exports, meaning delays are costing the economy millions of dollars a day as weeks of flooding which stretched from Arkansas to Louisiana takes its toll.
The mayor of Natchez, Jake Middleton, said he has met officials to discuss closing the river as an extreme measure to stop the flood defences being breached. He said: “You have two hospitals, a convention centre, a hotel and a spa on the Louisiana side. On our side, we have a restaurant and bar and several very old, historic buildings that we are trying to save.”
Coast Guard commander Mark Moland said measures such as sandbags that are in place to protect most of the area would hold up as long as the boats move one at a time and as slowly as possible.
The river is expected to stay at this swollen level for weeks in some areas and it remains unclear how long shipping will be disrupted.