High, clogged river snarls vessels, bogs down world’s top trade artery
8th February 2016 · 0 Comments
By Susan Buchanan
Contributing Writer
Heavy Midwest rain sent sediment and debris down the Mississippi River this winter, clogging the lower channel and raising the need for dredging to accommodate vessels. Rapid currents, along with increased sediment, are blamed for a string of recent accidents involving ships and barges.
When sediment builds on the Lower Mississippi, shippers are faced with draft reductions, forcing them to carry less cargo and forgo revenue. A ship’s draft is the vertical span from the waterline to the bottom of the vessel’s hull.
In New Orleans, the Mississippi crested at 17.06 feet on the Carrollton Gauge on Jan. 16 and was just below 14 feet last week. “In the extended forecast, it will fall to 12.1 feet by March 2 but that’s a ballpark number,” said Sean Duffy, executive director of the New Orleans-based Big River Coalition, which includes over 100 maritime entities.
“My biggest concern is being able to restore or maintain federally-authorized, channel dimensions at Southwest Pass for deep-draft vessels,” Duffy said. Southwest Pass in Plaquemines Parish is at the tip of the Mississippi River Delta. “We’ve lost six feet of draft in the Pass as sediment builds, and we’re coordinating with the Corps and dredging industry for more equipment,” he said. “We’ll lose more draft if additional dredges aren’t secured soon.”
At the U.S. Army Corps of Engineers, “an average $102 million spent on dredging the Lower Mississippi in the past five years won’t be adequate to restore channel dimensions this year,” spokesman Matt Roe in New Orleans said. “Dredging is necessary now for the current flood event, and it will be needed for the remainder of the high-water season, typically February through June.”
The New Orleans district is waiting for spending authorization for dredging from Washington. “Congress has passed the budget, and the Army Corps headquarters is allocating funds for projects,” Roe said. “We expect to receive our fiscal 2016, work-plan amounts in the second week of February.”
Dredging needs have grown after the Mississippi’s record level in January caused significant shoaling in the river’s lower parts much earlier than in an average year, Army Corps spokesman Ricky Boyett in New Orleans said last week. Shoals are sediment and sand deposits that can threaten navigation.
“This shoaling will continue as long as the river remains high,” Boyett said. “An average year’s funding for dredging wouldn’t restore the channel to full, project dimensions of 45 feet by 750 feet between New Orleans and Southwest Pass, and 45 feet by 600 feet in the lower part of Southwest Pass.”
“We expect to receive this year’s allocations for dredging Baton Rouge to the Gulf of Mexico in the coming days,” Boyett said Wednesday.
The hopper-dredge Newport and the government’s hopper-dredge McFarland are working in Southwest Pass now, Duffy said. A contract for the Newport—which is owned by Seattle-based Manson Construction Co., with an office in Houma—was extended by a month to Feb. 29. The Army Corps dredge McFarland arrived at Southwest Pass on Jan. 22 from Philadelphia.
“We need at least four dredges to maintain the channel and to keep up with shoaling, which will become harder to address as water levels recede,” Duffy said. “The two hoppers that the Corps is working with in two locations can’t keep up. We hope to keep both pieces of equipment and to secure a cutterhead dredge by the end of February.” The Corps New Orleans district pays for these dredges out of its operations and maintenance budget.
To prevent flooding, the Army Corps on Jan. 10 opened the Bonnet Carre Spillway, 12 miles west of New Orleans in St. Charles Parish. The structure, located at miles 128.8 to 127.3 above Head of Passes, directs water into Lake Pontchartrain and then out to the Gulf. In total, 210 of the spillway’s bays were opened.
On Jan. 25, the Corps began closing bays, however, because the river’s stage had dropped. “The final bays were closed on February 1, concluding the spillway’s operation for this high-water event,” Boyett said. “The operation lasted for three weeks, and at its peak we diverted about 200,000 cubic feet per second into the lake.” The spillway was first used in 1937, and has now been opened eleven times during its life, but only twice in January.
Because of additional sediment, vessels have to lighten loads, Duffy said. “Some ships might go to other ports instead, or they could return here once the channel is restored,” he said. Fast river currents have hampered barge traffic and usage, particularly around Mississippi’s Vicksburg Railroad Bridge—where at least five, recent marine accidents occurred.
In New Orleans, a section of river was shut for nearly six hours on Jan. 15 after a towboat hit moored barges near the Crescent City Connection bridge, and six of them broke loose, Coast Guard spokesman Ryan Tippets said. Twenty gallons of petroleum product spilled into the water. On Jan. 21, part of the river was closed for twelve hours in Plaquemines Parish after 22 barges, carrying coal and petroleum, broke loose and damaged three ships.
Also on Jan. 21, a towboat with six barges hit a bridge between Natchez, Miss., and Vidalia, La. One of the barges leaked slurry oil into the water. Then in a Jan. 26 collision between two tow vessels, a barge carrying caustic soda capsized near Hahnville in St. Charles Parish, shutting five miles of river temporarily.
Last Tuesday, the Cyprus-flagged tanker Nordbay struck a piling associated with Jefferson Parish’s water intake, without affecting the intake. The empty Nordbay then struck the Spain Street Wharf near Crescent Park in the Bywater as it headed to the New Orleans General Anchorage. All of these recent incidents and their causes are under Coast Guard investigation.
“The Mississippi is the world’s top trade artery, and blockage in one spot causes pain in other parts of the navigation system,” Duffy said. “For it to work efficiently, we need full channel dimensions maintained for ship and barge movement.” Shippers and pilots want supplies to flow. “The Associated Branch of Pilots for the Port of New Orleans, or Bar Pilots; the Crescent River Port Pilots; the New Orleans-Baton Rouge Steamship Pilots; and the Associated Federal Pilots are doing all they can to keep traffic moving,” he said.
“Bar Pilots limit the drafts of all vessels transiting Southwest Pass, where there is significant shoaling already,” Duffy said. They’ve kept the pass open but that will become harder to do as the river gradually falls.
“People are asking when the channel, which was reduced to 41 feet on January 30, will return to its maximum draft of 47 feet,” Duffy said. “We’ve made progress in securing dredges, but we need more and are keeping fingers crossed that we’ll have enough equipment.”
The Army Corps in New Orleans, the agency’s Mississippi Valley Division and its Washington headquarters have coordinated with navigation leaders and the dredging industry to find solutions, Duffy said. “But the Army Corps has solicited five contract bids for dredges that couldn’t be awarded, or were not bid on.” That’s because out of the 13 hopper dredges that can work the Mississippi River, each of them was either already under contract or in a shipyard for work.
“We need more shovels, or else the next draft reduction here could impact trade through the Panama Canal, which has a maximum draft of 39 feet 6 inches,” Duffy warned. “Despite tremendous efforts here, the message being heard around the world is that the Mississippi River is unreliable.” With additional dredges, it would still take a month or more to restore the channel in Southwest Pass, he said.
This article originally published in the February 8, 2016 print edition of The Louisiana Weekly newspaper.
