Drought and Barge Traffic on the Mississippi River

On Saturday, the US Corps of Engineers began releasing water from Lake Carlyle (east of St. Louis), which flows down the Kaskaskia River into the Mississippi River near Thebes. They kept the water level higher than usual on Lake Carlyle this fall, in anticipation of this move. As the article below states, it’s a short-term measure.

Corps Releasing Water from Carlyle Lake to Secure Mississippi River Traffic (USA)

And for you drought history buffs, during the 1988 drought Governor Thompson (Illinois) suggested increasing flow out of Lake Michigan and down the Illinois River to aid in navigation on the Mississippi River. Stan Changnon discussed this in an article on the 1988 drought and it’s impacts on the barge and railroad industries. The abstract of that article summarizes the situation:

The drought of 1988 rated as one of the nation’s worst in the past 100 years, resulting in a myriad of impacts and responses. A notable, largely unexpected impact involved stoppages of barge traffic on the lower Mississippi River during June and July, a result of shallow areas produced by record low flows and shoaling. The barge industry hauls 45% of all bulk commodities (grains, coal, petroleum) shipped in the central United States. The low flows were a result of the unusually large areas extent of drought conditions across most of the Mississippi Basin, which comprises 40% of the continental United States. Most 1987 months had been relatively warm and dry, minimizing moisture in the soils and shallow ground water. Then deficient snowmelt (due to low winter snow-falls) and record low spring 1988 precipitation combined to produce the record low flows along much of the Mississippi River.
Most responses to the drought came in a crisis mode and included concentrated dredging to open channels, government enforced reductions in barge loads and in numbers of barges per tow, tripled barge shipping rates, and shifts in transportation modes. The barge industry suffered a 20% income loss. The total losses to the barge industry coupled with higher costs for shipping were $1 billion. The Illinois Central Railroad, which parallels the major blocked waterways, used a climate prediction to anticipate the low flows 3 months in advance. They leased additional cars to help handle the increased shipments transferred from barges and made a sizable profit. A response proposed by Illinois and shippers—a temporary increase in the water diverted from lake Michigan to raise the levels on the lower Mississippi River—was met with strong objections by other lake states and Canada. The federal government declined the proposal, but the sizable controversy it engendered reflects the growing sensitivity to water resources issues in the Great Lakes Basin and is also illustrative of problems to be expected from a drier future climate (as hypothesized by certain global climate models as a result of ever-increasing trace gases in the atmosphere). This case study illustrates the value of using seasonal climate predictions of limited skill, and the need for better near real-time climatic data, including information about physical impacts of current climatic conditions.

Why the Low Water Levels on the Mississippi River

There has been much concern with the low river stages on the Mississippi River between St. Louis and Cairo, IL, and what that means for barge traffic, for example here and here.
How bad is it? The first graph shows the river stage at Chester, IL, from January 2011 to present. The river was actually above flood stage for much of May-July 2011. It dropped from almost 40 feet during that time to 5 feet in November 2011. Then it fluctuated between 5 and 25 feet, until this summer when it dropped below 5 feet and into negative numbers in late September. The latest forecast from the NWS has the river stage reaching -2 feet by December 10 (second figure). By the way, you can get negative river gauge heights because the reference point on the gauge (zero) may not always be the bottom of the river.
The reason for the low river stages in the stretch between St. Louis and Cairo is that much of the Upper Mississippi River basin and the entire Missouri River basin are in some stage of drought, according to the U.S. Drought Monitor (last figure). For the Missouri River basin, 90 percent of the basin is either abnormally dry or in some stage of drought. In fact, 41 percent of the basin is in D3 or D4, the two worst categories of drought.
Conditions are just as bad on the Upper Mississippi with 96 percent of the basin either abnormally dry or in some stage of drought. However, only 17 percent of the basin is in D3 or D4 drought. So drought is a little more widespread but not as severe in the Upper Mississippi River basin as it is in the Missouri River basin. Unfortunately, the latest NWS drought outlook indicates that the drought is expected to continue across much of these two basins through this winter.

Table 1. Percent coverage by USDM drought stage for each basin as of November 20, 2012. Data courtesy of the National Drought Mitigation Center. 
None D0-D4 D1-D4 D2-D4 D3-D4 D4
Missouri River 10.3 89.7 82.8 67.1 41.2 21.9
Upper Mississippi River 4.4 95.6 76.9 34.9 16.5 0

Mississippi River levels at Chester, IL. Source: USGS. Click to enlarge.

NWS forecast of the Mississippi River stage at Chester, IL, through December 10.

U.S. Drought Monitor map for November 20, 2012. Click to enlarge.

Midwest Drought and Barge Traffic

In the last few days there have been a number of articles like this one in the Peoria Journal Star about the slowdown of barge traffic along the Mississippi River due to the Midwest drought.
As the article mentions, we faced a similar situation in 1988. Stan Changnon, Illinois State Water Survey, wrote about the costs and other issues related to this in an article in the Bulletin of the American Meteorological Society.
Basically, in 1988 the barge industry lost about $1 billion due to low flows on the Mississippi as well as the Missouri and Illinois Rivers. The winner turned out to be the railroad industry as shippers scrambled to find alternative transportation for grain and raw materials.
Here is the graph of water levels on the Mississippi River at Chester, IL (south of St. Louis) since 2011. As you may recall, record rains in spring of 2011 caused much flooding on the lower Mississippi River. In fact, they had to blow some levies to save Cairo, Illinois. After facing heights of up to 40 feet in May 2011, levels fell throughout the rest of 2011 before leveling out in the winter and spring 2012. Since May of this year they dropped again to a current gauge height of about 1 foot. All these heights are in reference to the bottom of the gauge, not the bottom of the river. There is still water in the river – just not much.
You can find more of these at the USGS streamflow web site.

River stages on the Mississippi River at Chester IL since January 2011. Note the high stage last year of 40 feet, compared to about 1 foot this month. Source: US Geological Survey.