In a stunning reversal, runoff into the Missouri River's upstream reservoirs dropped to a record low in September, a little more than a year after historic flooding engulfed the Missouri River basin from Montana to Missouri.
Instead of battling the river by opening the gates on dams and blockading communities downstream with sandbags and emergency levees — as it did in the summer of 2011 — the U.S. Army Corps of Engineers this coming winter will cut back releases to minimal levels to conserve water.
Jody Farhat, who manages the reservoirs for the Omaha District of the corps, said the reductions will begin in December, and further drought measures are possible next year.
The corps will curtail normal winter releases by about 30 percent, allowing only 12,000 cubic feet of water per second to flow from Gavins Point Dam. Last summer, at the peak of flooding, 160,000 cubic feet per second flowed out of Gavins Point — more than double the previous high.
Utilities and communities downstream from Gavins Point, including the Omaha Public Power District and the Omaha area, face potential problems from curtailed releases, Farhat said.
As less water is released into the river during the winter, the likelihood of ice jams increases. This creates a potential chain reaction in which the ice jams cause river levels to drop downstream, potentially below the level needed for pipes that supply drinking water to cities and operational water to power plants.
The corps will monitor conditions closely, Farhat said, and increase releases if ice jam conditions threaten. Additionally, most communities and utilities have taken precautions to account for this threat after St. Joseph, Mo., was crippled by an ice jam in 1989.
Farhat said the corps intends to continue conserving water into next year, but that may not be enough to protect all recreational use of the upstream reservoirs. The three upper reservoirs could drop by as much as 10 feet below their desired level next year, she said. At the Fort Peck Reservoir, especially, some boat ramps may close.
Another consequence of continued drought could be the need to lessen releases during next year's navigation season. If that happens, barges probably would have to carry lighter loads.
Additionally, hydropower electric generation could be cut back.
The drought, which has been causing so many problems across the country, was relatively slow to intensify in the upper basin of the Missouri River. It's only been in the past month or so that the drought has become extreme in the upper basin, according to records gathered by the National Drought Mitigation Center.
Runoff into the reservoirs was at about 25 percent of normal in September, or about 285,000 acre feet, Farhat said. The previous record low for the month was set in 1919.
The all-time lowest runoff was 180,000 acre feet in August 1988, Farhat said. Records for the river date to 1898.
Even though runoff dropped off steeply this past summer, the corps has had to maintain sufficient releases of water to guarantee a deep enough channel for barge traffic.
Because of this, the corps has used about 20.5 percent of its drought cushion this year, Farhat said.
“It's a lot to draw in one year,” she said.
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