Wednesday, August 22, 2012

Mississippi River closed because of low water levels


To those of travelling in Tamilnadu, river sans water is a common sight.  Nearer we have Palar, which not many would have seen flowing.  Sadly, even in the rice belt of Thanjavur, river Kaveri trickles down with not much of water……… elsewhere in the World there are rivers known for boat and ship transportation.

The U.S. Coast Guard says that  97 boats and barges are waiting for passage along an 11-mile stretch of the Mississippi River that has been closed because of low water levels. Coast Guard spokesman Ryan Tippets is quoted as saying that the stretch of river near Greenville, Miss., has been closed intermittently since Aug. 11, when a vessel ran aground.  Tippets says that the area is currently being surveyed for dredging and that a Coast Guard boat is currently replacing eight navigation markers. He says 40 northbound vessels and 57 southbound vessels are currently stranded and waiting for passage.  It is not immediately clear when the river will reopen.  It is reported that the stretch of river that has been closed is a possible site for more groundings.

History has it that the ‘Great Mississippi Flood of 1927’ was the most destructive river flood in the history of the United States. The flood began when heavy rains pounded the central basin of the Mississippi in the summer of 1926. By September, the Mississippi's tributaries in Kansas and Iowa were swollen to capacity.  The water level at 56.2 feet (17 m) that was reached during that time remains a record till date.   The Mississippi River broke out of its levee system in 145 places and flooded 27,000 square miles (70,000 km2).  The flood affected many States with Arkansas  being the worst hit.   That is history as the places are facing a severe drought.  

The Mississippi River is the chief river of the largest river system in North America.  Flowing entirely in the United States (though its drainage basin reaches into Canada), it rises in northern Minnesota and meanders slowly southwards for 2,530 miles (4,070 km) to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi'swatershed drains all or parts of 31 US states and 2 Canadian provinces between the Rocky and Appalachian Mountains. The Mississippi ranks as the fourth longest and tenth largest river in the world.

A clear channel is needed for the barges and other vessels that make the main stem Mississippi one of the great commercial waterwaysof the world. The task of maintaining a navigation channel is the responsibility of the United States Army Corps of Engineers.  A series of 29 locks and dams on the upper Mississippi, most of which were built in the 1930s, is designed primarily to maintain a 9 feet (2.7 m) deep channel for commercial barge traffic.

Now, the river’s water levels are at near-historic lows from Cairo, Ill., where the Ohio River empties into it, to New Orleans, just north of its endpoint at the Gulf of Mexico.  The lowering of water levels is affecting everything from commerce on the maritime superhighway to recreation to the drinking water in Louisiana.  The biggest impact may be on shipping.  Statistical reports of American Waterways Operators, a trade group  put that about $180 billion worth of goods move up and down the river on barges, 500 million tons of the basic ingredients for much of the U.S. economy.  It carries 60 percent of the nation’s grain, 22 percent of the oil and gas and 20 percent of the coal, according to American Waterways Operators. It would take 60 trailer trucks to carry the cargo in just one barge, 144 18-wheeler tankers to carry the oil and gas in one petroleum barge. The low water levels mean that barge companies have to lighten their load by about 25 percent so the barges ride higher in the water, reducing what’s known as the barges’ “draught.”  That means each tow boat is moving less cargo than usual even though “it takes up the same amount of fuel to burn and the same amount of manpower,”.   Newspaper reports suggest that this summer there have been more than 15 cases of barges running aground.  In some places, the Mississippi is a one-way river as barges heading north have to wait for traffic headed south, adding to the costly delays.

Now nearly  100 boats and barges  are reported to be  waiting for passage along an 11-mile (17.7-kilometre) stretch of the Mississippi River that has been closed due to low water levels, the U.S. Coast Guard said.  The U.S. Army Corps of Engineers is using dredgers to dig out sand and ensure the navigation channel is deep enough for barges loaded with coal, steel, agricultural products and other goods. The corps is required to provide a minimum navigation channel that is 9 feet (2.74 metres) deep and 300 feet (91.4 metres) wide on the lower Mississippi River.

Far cry and far different from what it was in May 2011, when historic flooding forced US Coast Guard to shut down commercial traffic on part of the river.  That time the river was flowing unabated and reportedly looked about two miles wide as it had breached its borders.  The Coast Guard closed a five-mile stretch of the river at Caruthersville, Missouri, to prevent waves generated by passing barges from damaging levees and flood gates along the river.  There were reports of 25 barges breaking  loose near Baton Rouge - two of them hit a bridge before they could be secured.  

With regards – S. Sampathkumar.
22nd August 2012.

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