By GRANT SCHULTE and JOSH FUNK
HAMBURG, Iowa - Workers raced Tuesday to add several feet to a temporary levee that is now the only barrier between the small town of Hamburg and the menace of the rising Missouri River.
Crews from the Army Corps of Engineers planned to increase the levee's height by three feet. But time was short and the stakes were high: If the levee were to fail, parts of this southwestern Iowa community could be under as much as 10 feet of water within days.
The temporary earthen levee became the last line of defense for Hamburg after the river ruptured two levees in northwest Missouri on Monday, sending torrents of water over rural farmland toward Hamburg and a Missouri resort community downriver.
The Army Corps does not expect those floodwaters to reach Hamburg until at least sometime Wednesday. Initially, the floodwaters were projected to reach Hamburg on Tuesday.
The Missouri River is rising because the corps has been releasing massive amounts of water from its dams to clear out heavy spring rain and snowmelt.
Those releases at Gavins Point Dam in South Dakota hit the maximum planned amount Tuesday morning. So officials downstream in Nebraska, Iowa and Missouri will be watching closely for more levee problems.
Parts of Montana, North Dakota and South Dakota, have already seen some flooding, and officials predict the problems will linger through the summer because of the large volume of water already in the river, and the above-average Rocky Mountain snowpack.
About 45 miles south of Hamburg in Missouri, the river broke through a levee near Big Lake in Holt County. About 30 residents had stayed in the resort town after the river started rising, but they were told to leave Monday.
When work is complete in Hamburg, a town of 1,100 people, the finished levee should be about eight feet tall.
To help buy some additional time for the levee improvements, the corps said it planned to intentionally breach the main levee that failed Monday at a point downstream. Doing so should slow the flow of water.
The corps started building the new Hamburg levee last week after finding problems in the main levee in Missouri that failed Monday.
If Hamburg's new levee were to fail later this week, parts of the town could be covered by as much as 10 feet of standing water for months.
Several businesses near the remaining levee stood empty Tuesday, as crews continued to move dirt around the new earthen levee to protect Hamburg.
Todd Morgan with A&M Green Power Group says the owners of the John Deere dealership had relocated their business to one of the company's other dealerships in Shenandoah 25 miles away.
"We wanted to play it safe than sorry," Morgan said. "Every day that goes by, you seem to hear something different. With the breach yesterday, we just don't know what the integrity of that levee is."
Morgan said he doesn't know whether the dealership will return.
Fremont County Sheriff Kevin Aistrope said all but seven of the roughly 40 households in the southern part of Hamburg have evacuated voluntarily. The remaining seven have moved all of their furniture and can escape quickly if the town is flooded, he said.
Aistrope said the department has summoned 20 part-time reserve deputies, in addition to the regular eight-member staff, to help with law enforcement and traffic.
Funk reported from Omaha, Neb. Associated Press videographer Robert Ray in Hamburg, Iowa, and AP writers Maria Fisher in Kansas City, Mo., and Melanie Welte in Des Moines, Iowa, also contributed to the story.
National Weather Service river forecast: http://water.weather.gov/ahps2/index.php?wfooax
U.S. Army Corps of Engineers Omaha District: http://www.nwo.usace.army.mil
U.S. Army Corps of Engineers Kansas City District: http://www.nwk.usace.army.mil