The creek is expected to rise above flood stage by Wednesday afternoon, and fall back below flood stage later Wednesday.
The flooding was the worst in almost a decade in places, though the situation was expected to improve quickly over the weekend, according to Mike Gillispie, National Weather Service hydrologist in Sioux Falls.
In the section of the Missouri River meandering through southeastern Nebraska to the Iowa border, the Cooper Nuclear Station declared a "notification of unusual event" early Friday morning, signaling that the river had surpassed a height which causes concern.
Marc Chenard, a meteorologist with the National Weather Service, told NPR many areas will remain water-logged for days.
The flooding shut down roads, forced scores of people to evacuate their homes and cut off access to some towns and cities.
Heartland Coop crews have moved equipment to higher ground and citizens are working this morning to clear out a storage building near First Street.
The GRCA said much of the snow pack is expected to melt and increase runoff into local waterways. Through the weekend, the most significant flooding is forecast to shift to the larger rivers in the region.
Nigeria school collapse: Pupils feared dead in Lagos
The top floor of the building is occupied by a school with about one hundred pupils, while the rest are residential and shops. A crowd of thousands of people cheered on Wednesday as dust-covered, shocked-looking children were pulled from the rubble .
Officials are confident that the flooding around the plant presents no danger to the public, power district spokesman Mark Becker said.
Officials in western Iowa and eastern Nebraska were urging people not to drive unless necessary.
The neighboring cities of Fargo and Moorhead, Minnesota, experienced a record flood 10 years ago.
A roadside sign is almost engulfed in water from the flooding Rock River at Castle Rock State Park along state Route 2 near Oregon.
A flood warning has been issued for the Missouri River at Kansas City as well.
When it does, he said, there will be another round of flooding in those states that will then move south along the MS into IL and Iowa. State police said first-responders say at least 21 homes were damaged, though no injuries have been reported.
Water is at the top of the federal levee on the Iowa side and is inches from overtopping the "super berm" built to protect Highway 2 between Nebraska City and Interstate 29. "I have no place to go", said Dale Chaney of Percival. We now do not have any county or state roads closed.