The Army Corps of Engineers plans to lower water releases from Garrison Dam by 5,000 cubic feet per second today, but how the height of the Missouri River will react is uncertain.
The corps said it will bring the release rate from 140,000 cfs to 135,000 cfs today and to 130,000 cfs on Thursday. It will continue to lower the level by increments of 5,000 cfs and reach 105,000 cfs by Aug. 4, according to its latest schedule, which can be foundatwww.nwd-mr.usace.army.mil/rcc/reports/twout.
The corps began lowering releases from the peak of
150,000 cfs on June 26, but the Missouri River has held steady near
19 feet, rising and falling slightly since then.
"We don't really know what's going to happen," said Steven Robinson, a hydrologist with the U.S. Geological Survey in Bismarck. "It's a complex system and there are a lot of interactions we haven't seen or experienced before."
The river was at 19.09 feet at 4:30 p.m. Monday. The National Weather Service projects that it will fall to 18.5 feet by Saturday. But the river did not follow similar predictions when releases were lowered earlier.
"There's been no dramatic shift either way with their release schedule," said Mary Senger, Burleigh County emergency manager. "The river's falling, but it's very slow."
Tammy Lapp-Harris, the emergency manager for Morton County, said her office had been preparing guidelines on assessing and repairing damage to homes, but is are waiting to release it when water recedes enough to allow people access to their property.
"We're not going to release that until people feel comfortable taking down flood protections," she said.
Because the river at Bismarck has not reached flows above
65,000 cfs since the construction of Garrison Dam, predicting what it would do as it rose was difficult. Experts face a similar problem now that its flow is falling.
"The people in the water business that used to know the Missouri at 140,000 or 150,000 cfs, those people are gone," Robinson said. Even the last big flood in 1952 provides little guidance since the river did not have the Oahe Dam downstream to hold back flows, he said.
"All I can say is, I guess we'll find out," Robinson said.
(Reach reporter Christopher Bjorke at 250-8261 or firstname.lastname@example.org.)