COLUMBIA — Workers at the city's water treatment plant in the Missouri River bottoms are getting the boats out of storage.
Two levees protect McBaine from river levels up to 32 feet, and a flood wall at the plant itself can withstand up to 40 feet, said Floyd Turner, Columbia's manager of water operations.
If the Missouri River overflows the levees along the river, though, plant workers will need their two 14-foot boats to navigate between the nearby wells and possibly transport workers to and from the plant.
The water plant's staff was stockpiling sand for spot leaks along with other supplies in case floods limit access to the plant, engineer Michael Anderson said Friday. Workers at the plant were also checking on emergency generators in the event the plant loses electricity.
A forecast from the U.S. Army Corps of Engineers shows the Missouri River overflowing as many as 58 levees between Kansas City and St. Louis by the end of the month.
After a year's worth of rain in recent weeks and snowpack 140 percent above average in the upper Missouri River basin, the corps is releasing record amounts of water from six reservoirs in Montana and the Dakotas.
Diana McCoy of the corps' Kansas City office said the closest of these to Missouri, Gavins Point Dam on the South Dakota-Nebraska border, will release at 150,000 cubic feet per second by June 13. The reservoir's previous record was 70,000 cubic feet per second in 1997.
Those releases will raise the Missouri River to a minimum of 27 feet in Boonville by June 18, and water levels could reach 33 feet, McCoy said. Those levels, 6 to 12 feet above flood stage, would last at least into August — and that's assuming normal rainfall in the Missouri River watershed below Gavins Point.
If the river reaches the high end of the forecast, it would overflow 58 of the 95 non-federal levees between Kansas City and St. Louis.
Threatened levees include those maintained by the McBaine Levee District that help protect Columbia's water treatment plant. According to the corps, the levees at McBaine would overflow at a river level of 30.5 feet.
John Sam Williamson, president of the McBaine Levee District, said the levees can actually withstand levels up to 34 feet in some places and up to 33 in others.
Two sections of the McBaine levees need repair, Williamson said, because continuously high river levels have eroded them.
"If we weren't going to have floods, we would need to do this anyway," he said. "The fact that there is high water, that makes it more imperative to get it done as soon as we can."
Williamson said repairs will begin Monday on a 300-foot-long section of the primary levee that runs along Perche Creek. He expects that repair to be finished Thursday. Once it is done, work will begin on a 1,200-foot section of the secondary levee that runs along the Missouri River bank. Both sections need to be pushed back roughly 30 feet to rejoin the rest of the levee.
The primary levee is higher and further inland than the secondary one and protects more valuable land, Williamson said, which makes it a higher priority.
"We're doing everything we can to make sure our levees are strong and safe," Williamson said. "You do the best you can, and things may happen or they may not."
The levees are in better condition than in 1993, though, Williamson said. The McBaine Levee District formed following the record flood in 1993 and brought the levees up to corps standards for the first time, he said.
Protection immediately surrounding the water treatment plant at McBaine also was increased after 1993, Turner said, to withstand another flood of the same magnitude — a record 37.1-foot crest at Boonville.
The corps also forecast the river would overflow the Plowboy Bend Levee, across from Cooper's Landing, and all three sections of the Hartsburg Levee District.
Frank Drummond, manager at the Plowboy Bend Conservation Area, said that the levee there was in good condition and that in the last 10 years he's seen it withstand levels near 30 feet. If the river does top the levee, he expects total failure of the Department of Conservation's 700 acres of corn and soybean crops in the river bottom.
"At 30 feet and change, the levee is fine," he said. "At 33, I don't know about that."
In the Jefferson City area, the corps expects the river to overtop 15 of 16 levees if it crests at or above 35 feet, the high end of the forecast. The National Weather Service issued an advisory late Thursday stating that "if rainfall is above the long term average this summer ... major or even record flooding could result."
Normal rainfall for June in the Missouri River Basin is between 3 and 5 inches over the past three decades, but surpassed that in each of the last three years, according to data from the National Weather Service. The Climate Prediction center expects June to be above normal again this year.
Even if rainfall is above normal and contributes to major flooding, Williamson thinks the odds are slim of reaching a situation like 1993.
"That was a 500-year flood," he said. "The odds of that happening are 1 in 500. We're not betting on anything out here, and we're not going to give up. But the odds of that happening again in our lifetime are very small."