A plan released last month by the U.S. Army Corps of Engineers would deepen portions of the Mississippi River navigation channel, including stretches between New Orleans and Baton Rouge, to 50 feet. The channel’s current depth measures 45 to 47 feet.

The dredging would allow Mississippi River ports like Plaquemines, New Orleans, and South Louisiana to handle larger neopanamax vessels that were built to take advantage of the expansion of the Panama Canal.

The new Panama Canal locks can handle ships as large as 14,000 TEU. The previous maximum was in the neighborhood of 5,000 TEU.

U.S. ports on all three coasts completed similar dredging projects or have applied to get them approved. The recent passage of the Water Infrastructure Improvements for the Nation Act (WIIN) Act signed into law by President Obama on December 16, will facilitate finding of these types of projects. The legislation authorizes $100 million for beneficial use dredging.

The increased Mississippi River depth will obviate the need for larger vessels to travel light on the waterway and to unload cargo before they enter the river’s mouth. The deeper dredging will increase intervals between maintenance dredging.

The deepening project would have an initial cost of $88.9 million, of which the Louisiana Department of Transportation and Development would pay $22.2 million.

The Corps of Engineers estimates that maintaining and operating the deeper channel will cost about $21.6 million a year, all would be paid by the federal government, and that the annual benefit to the U.S. economy would be $96.8 million. The project would take as four years to complete.

The corps expects to use dredge sediment to create over 1,400 acres of new wetlands in the federal Delta National Wildlife Refuge and the state Pass A Loutre Wildlife Management Area. The corps study cites the wetland creation program as a benefit of the project to offset its other environmental effects, including the loss of over 800 acres of wetlands over 50 years due to salt water seepage.

The Port of New Orleans requested that access between wharves and the channel also be deepened to 50 feet. Those provisions are not included in the corps’ current plan.