(Reuters) - Emergency crews have erected nearly 10 miles (16 km) of temporary flood barricades and laid a quarter-million sandbags in Cedar Rapids, Iowa, as residents braced on Monday for what could be the second-largest flood in the city's history, officials said.

Iowa's second-biggest city is hoping to avoid the widespread destruction caused by the U.S. Midwest floods of June 2008 that inundated hundreds of businesses and thousands of homes in Cedar Rapids.

"It's crunch time in Cedar Rapids," Mayor Ron Corbett told residents and reporters on Monday.

"The next 48 hours are the most critical. The next 48 hours are the most dangerous."

The Cedar River, which winds through the city of around 126,000 in eastern Iowa, is expected to crest early on Tuesday morning at 23 feet (7 m). The water had reached over 16 feet on Monday, which is considered major flood level.

The city management office said that around 5,800 homes and businesses were in the evacuation zone, which runs along the banks of the river.

"If you are in the evacuation zone, go pack up the suitcase right now and head to higher ground," Corbett said.

He said he expected that residents in the evacuation area would likely be able to return to their homes and businesses on Saturday.

The National Guard was expected to be in position by noon on Monday to man traffic checkpoints and aid in evacuation efforts.

The Red Cross, which is operating two shelters, said personnel were being brought in to assist with those who had left their homes.

Schools will remain closed until Wednesday, the Cedar Rapids Community School District said.

The city was hard hit by widescale flooding eight years ago which swamped towns and farms across the Midwestern United States.

More than 10 square miles (26 sq km) containing 5,400 homes and 700 businesses in Cedar Rapids were flooded in 2008.

(Reporting by Timothy Mclaughlin in Chicago; Editing by Matthew Lewis)