SIOUX CITY, Iowa - Record Big Sioux River flooding prompted residents in three states to hurriedly prepare for the rising water Thursday, with people lining up for sand bags and moving items - including museum artifacts - to higher ground.
The fast-moving Big Sioux has been swollen by days of thunderstorms and is expected to crest Friday more than a foot above the previous record level set in 1969, threatening homes and businesses in Iowa, Nebraska and South Dakota.
In North Sioux City, South Dakota, dozens of National Guard soldiers were rushing to fill sandbags for residents of the McCook Lake neighborhood, where up to 400 homes were in danger of flooding.
Residents including Ashley Caskey waited for hours in a line of pickup trucks that inched toward the sandbag filling stations.
"We are just happy to get sandbags at this point," Caskey said.
Tim Webster, who lives in an upstairs apartment on McCook Lake, said he wasn't worried about his place but was helping friends.
"Anybody who knows me knows I've got a truck, so let's do this," he said.
This is the worst flooding the region has seen since 2011, when the Missouri River remained high for months, causing tributaries to back up and testing the levee system. The fact that the levee held for long at that time showed it's effective, said Jade Dundas, assistant city manager for public works for Sioux City, Iowa.
This time, the Big Sioux should begin receding Saturday and stop flooding even nearby agricultural land by Monday morning.
"This kind of a quick up and down does give us some sense of confidence," Dundas said.
The city had to extend one of its levees by about 600 feet and that work is finished. On Thursday, Sioux City crews helped property owners fill sandbags as a precautionary measure, he said.
At The Railroad Museum near the river in Sioux City, volunteers helped staff move artifacts to higher ground because the main building will likely get about 5 feet of water, said museum executive director Matt Merk. Vintage rolling stock including a 1943 General Electric diesel locomotive was among exhibits moved to safety, Merk said.
"At the very worst at this point we'll have cleanup and nothing completely damaged except for some sheet rock," he said.
Crews were building a temporary levee that will run across Interstate 29. It should protect much of North Sioux City but will close off a few miles of the interstate and force motorists onto local roads between Sioux City and Sioux Falls to the north.
One potentially vulnerable area is Dakota Dunes, South Dakota, a community between the Big Sioux and the Missouri rivers. The existing levee has been raised and city officials said they're confident it will hold back the river, but an evacuation plan has been prepared if it's needed.
"We're building these levees to work," Jeff Dooley, the community's improvement district manager told the Sioux City Journal. "But things can happen. There are a million things that can go wrong."
Upstream in Akron, Iowa, a levee breached early Wednesday, causing flooding in a business district, but a temporary patch is holding.