The ongoing drought has river levels along the Mississippi River plunging to very low levels this summer and more serious issues for barge traffic are possible moving into the autumn if rainfall does not normalize.
Have you ever been delayed on an interstate highway during road construction, where two or three lanes are whittled down to one lane? This could be the developing situation on Old Man River in the coming weeks and months with barge traffic.
It was just last year when levels along the Mississippi River and many of its tributaries were close to record high levels. What a difference a year makes.
Falling river levels are not uncommon during the summer months in the central and eastern United States. However, the building drought over much of the middle of the nation currently has the mighty Mississippi running well below normal and levels in many areas are likely to fall in steps through the balance of the summer into the autumn, unless widespread and regular rain comes.
Along much of the Mississippi River, water levels continued to drop in the past week and will go lower moving forward this summer.
Low river levels along stretches of the Mississippi were already beginning to cause minor problems.
Thus far the main shipping channel is open and traffic is flowing freely, according to the United States Coast Guard.
However, very low water levels have exposed shoals, potentially putting river traffic at risk for running aground. Some docking locations are becoming too shallow to easily remove cargo. Some barge companies are lightening their loads to reduce the risk of getting stuck on the river bottom.
Officials in some areas are considering one-way traffic along portions of Old Man River due to the narrowing channel.
According to National Weather Service (NWS) Hydrologists river levels along parts of the Mississippi River are 30 to 50 feet lower this year, compared to around the same time last year.
While significant rain is forecast to fall by AccuWeather.com over portions of the northern and eastern part of the Mississippi drainage basin, a tremendous lack of rain will continue over the western, central and southern part of the basin for much of the summer.
According to NWS Hydrologist Steve Buan, at the North Central River Forecast Office, "As of July 6, 2012, river levels over the Upper Mississippi River are not 'yet' extraordinarily low."
Buan commented that heavy rain earlier in the summer from around Minneapolis to southwest of Duluth kept the river levels from reaching extremely low levels through the first part of July.
The flooding from up north early in the summer has run its course downstream.
As of July 26, the river level at St. Louis was 1.2 feet. The river level was projected by NWS Hydrologists to dip to near 0.0 feet around July 26.
According to St. Louis Army Corps of Engineers Public Affairs Chief Mike Peterson, "At the low water reference point of minus 3.5 feet, a safety zone is established in the navigation channel and some restrictions by the United States Coast Guard may be put in place."
The river bottom of the Mississippi is dynamic, always changing so that barge companies and pilots will police themselves until mandatory restrictions are in place.
"Officials will continue to patrol the river and may undertake dredging operations as necessary to keep channels and ports open," Peterson said.
The Mississippi River drains more than 40 percent of the United States and has the Arkansas, Illinois, Missouri and Ohio rivers as some of its major tributaries, all of which are experiencing abnormally low levels.
Compare the Mississippi River basin to the amount of real estate experiencing abnormally dry and drought conditions this summer.
Additional spotty rain over the Illinois, Ohio and upper Mississippi basin was causing levels farther downstream along Old Man River to fluctuate slightly during week three and four of July.
River levels along the Mississippi as of July 26, 2012 include: 10.0 ft. at Thebes, Ill.; 1.2 ft. at St. Louis, Mo.; 1.9 ft. at Vicksburg, Miss. and -6.9 ft. at Memphis, Tenn.
As a point of reference, on July 13, 1988, the river level at St. Louis was -1.0 ft.
Simply put, a negative river gauge reading can occur as the river bottom condition changes from natural causes or dredging.
Concerns for low river levels and their impacts will continue over the Mississippi basin well into the fall.
On average, river levels and water tables reach their lowest point during the autumn, barring intervention of tropical weather systems.
As a result the inconvenience to barge traffic going on now could become more serious progressing through the late summer and into the fall.
The drought has and will continue to cost local communities and American tax payers money through ongoing dredging operations. At the same time lighter loads will limit profits among barge companies.
This story was originally published on July 6, 2012 and has been updated.
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