The Army Corps of Engineers began reducing the flow of the Missouri River reservoir on Friday which has the potential to bring barge traffic along the Mississippi River to a halt, the Associated Press reports.
The corps' decision is in the best interest of the upper Missouri River basin. Both rivers have seen a big drop in water levels due to severe drought.
Barges are already required to carry lighter loads. If the water level at St. Louis dips below minus five feet, the river could be closed to barge traffic creating devastating economic consequences. The water level Saturday was at minus 0.44 feet. The Associated Press reports minus 5 feet could be reached by Dec. 10.
Water from reservoirs in Minnesota began heading downstream last week, but its only expected to help raise water levels a few inches.
USA Today reports $7 billion in commodities are shipped along the river in December and January.
More than 60 percent of grain exports and 20 percent of the country's coal is carried by barges. If a closure occurred, delivering fertilizer to the Midwest for spring planting would have to be shipped by trucks or train, creating higher costs for farmers.
Fifteen senators from Mississippi River states including Sen. Amy Klobuchar and Sen. Al Franken are urging the corps to take steps to keep barges moving.