Thursday, November 22, 2012
When will low water levels on the Mississippi halt river traffic?Tweet
The drought of 2012 may have diminished Cornbelt yields, but now it is diminishing the capability of getting the minimal crop to market. Low water levels in the Mississippi River watershed have threatened to close a portion of the mid-Mississippi between St. Louis, MO and Cairo, IL. That means southbound grain will not be delivered by barge to Gulf ports for export, and northbound fertilizers and fuel on barges may not be delivered in a timely fashion for spring planting. With little potential for heavy rains that will re-start tiles flowing, put water in drainage ditches, and raise levels in creeks, streams, and rivers, there is little chance of higher water levels in the Mississippi before next spring.
Ironically, 18 months ago, the St. Louis District of the Army Corps of Engineers (ACE) was challenged with high water, and intentionally destroyed the Bird’s Point levees south of St. Louis to divert water through 120,000 acres of farmland to prevent flooding of the community of Cairo, IL. The opposite is now happening, and river levels are dropping to the point that slabs of submerged bedrock threaten to ground barges and towboats operating in the channel of the river. Known as “pinnacles,” the ACE has focused its efforts to blasting them out of the river to provide a minimum 300 foot wide channel for barge tows to navigate.
The pinnacles that threaten navigation are along the river in the vicinity of Thebes and Grand Tower, IL. ACE provides a series of aerial photographs of the river, with hundreds of the masses of bedrock that clog the barge channel as the water level declines. The rock is an estimated 850 cubic yards of bedrock over 6-7 miles, which is best removed at low water levels. And the river level at Thebes has dropped over 1 foot from Nov. 19 to Nov 23, which not only will facilitate the rock removal, but further create problems for barge tows.
One of the complicating issues of keeping enough water in the Mississippi to maintain commerce is the management of water in the Missouri River, which is going into its winter phase. Flows of water are being reduced from reservoirs along the Missouri, which mean it will not contribute as much water to the Mississippi as it does during other times of the year. ACE is quite careful to acknowledge that a different division manages the Missouri River, compared to the Mississippi River, and the Missouri management is going according to plan despite the needs of the water in the Mississippi. Missouri River management chief Jody Farhat says the timing of more water flowing from the Missouri into the Mississippi will depend on the snowpack in the mountains and the Dakotas, where the headwaters of the Missouri originate.
Lou Dell’orco, chief of operations of the St. Louis District of ACE, in a special podcast interview, outlines the problems for the barges, the action underway to prevent a closure of the river, and how the decision will be made regarding more water being released from the Missouri River. He says it will be a political decision in the end that will balance the needs of commerce with the needs for water conservation.
ACE officials indicate past efforts to grind out the rock in concert with dredging were not effective, and blasting out the rock is the only alternative. However, the work cannot be done until February, and must be quickly completed to not interfere with the spawning season of certain fish.
While barge traffic on the upper Mississippi slows or stops over the winter due to ice, that is not the case with the mid-Mississippi from the confluence of the Missouri River and south. However, low water levels from St. Louis, MO, to Cairo, IL, are at historic lows because of the drought, and barge tows are being threatened with running aground on bedrock formations in the channel, as the river drops. Plans are underway to remove portions of the rock, but not for several more months.
Posted by Stu Ellis on 11/22 at 10:40 PM | Permalink