(Reuters) - The drought-drained Mississippi River will rise slightly later this week between St. Louis and Cairo, Illinois, but later continue its decline toward historic lows, according to a National Weather Service forecast.
Low water, due to the worst U.S. drought since 1956, has
already impeded the flow of billions of dollars worth of grain, coal,
fertilizer and other commodities between the central United States and
shipping terminals at the Gulf of Mexico.
A further drop in river levels could halt commercial shipping traffic entirely by this weekend, the American Waterways Operators and the Waterways Council Inc said in a statement on Wednesday.
Last week, the council said the river along the Cairo-St.
Louis stretch would be too low for navigation by January 7 but on
Wednesday it said shipping may come to a halt between January 5 and 15.
A shutdown could affect more than 8,000 jobs, cost $54
million in wages and benefits, and halt the movement of 7.2 million tons
of commodities valued at $2.8 billion, the two industry groups said.
The Army Corps of Engineers,
which is spearheading a project to remove river-bottom rock that could
impede shipping if the river becomes too shallow, remains optimistic
that the nine-foot-deep channel, which most commercial vessels need, can
be maintained.
Forecasts for warmer weather, which
would limit river-choking ice from forming, and the potential for rain
next week bolstered that outlook.
The Corps is removing the most threatening rock pinnacles near the Illinois towns of Grand Tower and Thebes
first, hoping to deepen the shipping channel by about two feet by
mid-January, just before the river was forecast to hit critically low
levels.
"The
Corps rock removal contractors are making excellent progress in removing
the rock obstructions from the primary area of concern," said Major
General John Peabody, the Corps' Mississippi Valley Division Commander.
"We believe we will deepen the channel ahead of the
worst-case river stage scenario, and I remain confident that navigation
will continue," he said.
The Corps has also been dredging various soft-bottom sections
of the river nearly round-the-clock for months to maintain a deep enough
shipping channel. The vast majority of commercial vessels need a depth
of at least nine feet so shippers are closely monitoring river gauges
and forecasts.
The Mississippi River gauge at Thebes fell from a reading of 4.45 feet
late last week to four feet late on Wednesday. It was forecast to rise
to 4.2 feet on Friday morning before slipping to 3.2 feet by next
Wednesday, the lowest level at Thebes since 1988 and the second lowest
on record.
Gauge
readings do not reflect the actual depth of the river at a certain
location because the gauges are fixed and the river's bottom is steadily
changing with the current. But they do aid navigation as a shorter term
reference point.
The Army Corps
has said once the Thebes gauge reads 2 feet, boats with a nine-foot
draft, or distance between the water's surface and the lowest point of
the vessel, would be at risk of hitting rock pinnacles there.
"We lose 9 feet of depth for the navigation at about 2
feet on the Thebes gauge," said Army Corps spokesman Mike Petersen.
"That's when those rocks become an issue."
(Reporting by Karl Plume in Chicago; Editing by Steve Orlofsky and Bob Burgdorfer)