Early flooding on Mississippi brings large amount of sediment, calls for early dredging to keep shipping channels open _lowres

Advocate file photo by AMY WOLD -- A dredge works at the Head of Passes in the Mississippi River in this 2014, much like is being done now to help clear out dirt brought down by the latest Mississippi River flood.

An early flood on the Mississippi River this year brought with it a large amount of sediment that is slowly filling in vital navigation channels on the lower river.

The extra dirt has cut into the recommended draft for all vessels going through the main navigation channel of Southwest Pass and has had the U.S. Army Corps of Engineers calling for earlier than normal dredging operations to keep the waterways open.

Normally, floods occur in the spring, and the Corps plans for the additional sediment when setting up a yearly dredging schedule for the mouth of the river as well as “crossings” of the river between Baton Rouge and New Orleans, Ricky Boyett, chief of public affairs with the Corps’ New Orleans district, wrote in an email.

This year, the January river flood was months earlier than expected and has led to significant shoaling in the Head of Passes and Southwest Pass. That shoaling, or underwater accumulation of dirt, will continue for as long as the water in the Mississippi River is elevated.

On Jan. 14, the Associated Branch Pilots of the Port of New Orleans reduced the allowable draft of vessels — how far they extend below the surface of the river — from 47 feet to 43 feet. That draft restriction was reduced again Jan. 29 to 41 feet, according to the industry group Big River Coalition.

The earlier-than-normal flood conditions mean the Corps has faced a challenge in finding available private hopper dredges to work on the river. Winter is the normal time for shipyard repair, so most dredges are either in dry dock or already working on other contracts, Boyett said.

The importance of the river’s deep draft channel to the country’s economy means the Corps is looking at every option it has to get the dredging on the river done.

Two hopper dredges are now working near Head of Passes, and a cutterhead dredge is scheduled to arrive soon, Boyett said. The Corps’ Dredge Wheeler is set to start dredging later this month after maintenance work being done in Charleston, South Carolina, is finished. In addition, the Corps is working on getting three more dredge contracts awarded.

The good news for the shipping industry is that although the current situation has been tough, there is help on the way, said Sean Duffy Sr., executive director of the Big River Coalition.

With two dredges now working in the river and another four scheduled to arrive by the end of the month, “it will go a long way to restoring the channel, but it will take a good while,” Duffy said.

With the first river flooding happening so early in the year, similar problems could recur in a few months if there is enough snow melt in the North to raise the river’s level again.

“Funding is going to be an issue because we’re using a lot of equipment,” Duffy said.

Follow Amy Wold on Twitter, @awold10.