Hamburg, Iowa ? Crews scrambled Monday to protect a southwest Iowa town from the swollen Missouri River, but local officials said it’s unclear whether they’ll be able to prevent the river from leaving the community under several feet of water for weeks.

If efforts to pile massive sandbags on a faltering levee and build a secondary barrier fail, part of Hamburg could be under as much as 8 feet of water for a month or more, Fire Chief Dan Sturm said. Flooding along the river this summer — expected to break decades-old records — will test the system of levees, dams and flood walls like never before.

“We’re working against the clock,” Sturm said Monday as many residents were packing up their homes and heading out of town. “There’s a chance we can save ourselves from the worst of it. We just need some time. But if water gets in here, it’s going to be here for a while.”

The earthen levee that guards an area of farmland and small towns between Omaha, Neb., and Kansas City has been partially breached in at least two places south of the Iowa-Missouri border. And emergency management officials expect new breaches in the coming days as the river rises.

That means Hamburg could be only the first of many communities to get hit.

The last time the Missouri River crested at levels predicted for this summer happened in 1952, before most of the major dams along the river were built. And the flooding is expected to last into mid-August.

The U.S. Army Corps of Engineers will be releasing more water than it ever has from the dams by mid-June, meaning there likely will be other levee problems like the ones near Hamburg, said Kevin Grode with the corps’ water management office.

“With these high flows, there’s the possibility of more levee breaches,” Grode said.

Officials also predict that the water will get high enough to flow over at least 11 levees in the area near Hamburg in the corners of southeast Nebraska, southwest Iowa and northwest Missouri.

The Army Corps of Engineers began building a secondary flood wall to protect low-lying areas of Hamburg because it expects the northernmost breach of the floodwall, which is 5 miles southwest of town, to fully give way at some point.