KANSAS CITY (AP) - The amount of water released into the lower Missouri River began increasing this week after August runoff was the third highest in more than a century, the U.S. Army Corps of Engineers said Friday.
Water management chief Jody Farhat said during a conference call that although river levels would rise three to four feet, the water is expected to stay in the channel unless there is significant additional rain. She described fall as a "very good time" to evacuate flood water and said the releases would ensure there is room in the reservoirs to handle next year's runoff.
Kevin Low, Missouri Basin River Forecast Center Hydrologist for the National Weather Service, described the chances for widespread flooding as "insignificant," although he said the likelihood of localized flooding was slightly increased.
Releases from Gavins Point, the lower-most dam on the Missouri River, are expected to climb to 45,500 cubic feet per second by Tuesday, up from an average of 28,500 cubic feet per second in August. The corps also was boosting water releases from the Oahe, Big Bend and Fort Randall dams, and the higher flows were expected to continue for about three months.
The releases come after portions of Montana, Wyoming and the Dakotas received more than 400 percent of their normal August precipitation, said Kevin Stamm, a hydraulic engineer for the corps. He noted that a large swath of central and north central Montana received more than 5 inches of rain and some areas received more than 10 inches.
The heavy rainfall in Montana led to damaged bridges and blocked and washed out roads.
August runoff has been heavier just two other times since 1898 - the heavy flood years of 1993 and 2011, Stamm said.
The excess water will allow the corps to extend the navigation season by 10 days, with it now ending at the mouth of the Missouri River on Dec. 10. The higher releases also will benefit winter hydropower generation and reduce the risks to water intakes when ice forms, the corps said.