HAMBURG, Iowa — The partial collapse of a levee near here — the first levee failure on the lower Missouri River since upstream dam releases were increased — underscores how vulnerable levees can sometimes be.
Area levee board members interviewed Monday said the levee that failed was considered to be in good shape and was not yet stressed by the full load the river is going to deliver. The failures occurred at the base of the levee, not at the top.
On Monday, officials provided more glimpses into how historic this year's flooding could be.
Kevin Grode of the U.S. Army Corps of Engineers said the amount of water flowing through Missouri River reservoirs is expected to exceed the dams' designed capacity for flood storage. Based on a flood in 1881, the reservoir system was designed to handle 40 million acre-feet of inflows. This spring-summer runoff (March through July) is projected to be around 44 million acre-feet.
Also on Monday, federal officials said Missouri River flooding this summer could rival what has already been seen this year along the Mississippi River and what occurred along the Missouri River in Missouri in 1993.
While no one knows why the levee near Hamburg partially collapsed, local officials said levees along the river are prone to similar problems.
The Army Corps of Engineers has been advising officials up and down the river to redouble their inspection efforts.
Levee problems are not unusual. Significant damage occurred last year near Percival, Iowa. In the Kansas City area, officials are hurriedly repairing damage caused by last year's high water so that the levee is ready to handle the rising flows.
The Hamburg levee partially collapsed in two spots southwest of town just across the border in Missouri, prompting a mandatory evacuation of about 20 percent of the community, or about 240 residents.
Residents of the town have been working together to get everyone to higher ground.
Eugenia Jacobson said her landlord is lending her family his semitrailer truck to move and store her stuff.
“He knows we don't have any family, and he's been good to us,” she said. “We couldn't find a storage place any place.”
The truck was mostly loaded on Sunday, and she prepared to move to her new home: a camper at a nearby campground.
“If it wasn't for the people of Hamburg, I don't know what we would do. We would have just picked up our clothes and our cat and high-tailed it somewhere,” she said. “We're just praying that it isn't as bad as they say it's going to be.”
Area levee officials said they were surprised that an otherwise reliable levee failed at a manageable flood stage.
By the end of next week, releases from Gavins Point Dam will be nearly double those flowing past the levees when the breaches occurred.
“This could be a warning (for others),” said Glen Stenzel, a member of one of the local levee boards in the area. “This levee has never caused us any trouble before. I've always been secure with it.”
Erik Blechinger, a spokesman for the Corps of Engineers in Omaha, said breaches this early were unexpected.
“These (breaches) may be localized. It may be that these two had a weak spot, but it's hard to speculate,” he said.
The corps also has been working with local officials on a levee problem across the river from Brownville, Neb.
The top official for the corps' Omaha District said the early failure of the Hamburg levee doesn't set a precedent for the others. “I don't think this is an indication of what we'll see and how other levees will perform,” said Col. Robert Ruch, commander of the Omaha district.
Corps officials have estimated that a 1,700-mile stretch along the Missouri River will probably experience some level of flooding in the months ahead.
The problems that plague levees are well-known and common: possible weaknesses from previous years' high water, burrows from animals or a vein of fill material that's vulnerable to erosion.
Ask anyone who knows these levees well and they'll say a combination of factors probably played a role, including a common foe: badgers.
“There's a good chance animals — varmints — might have had something to do with it,” said Charlie Zanker, who works with levees in the area. “In the past couple of years, we've had an absolute barrage of varmints.”
Badgers and other animals burrow into a levee, creating an opening for water that then can further erode the structure.
Stenzel was on-site at the first breach when the second occurred nearby on Sunday. He said he saw nothing before the breach that indicated a vulnerability.
Stenzel said he heard an exclamation from someone else there, turned and saw water beginning to pool on the dry side of the levee. “About the time I got my eyes focused,” he said, “the berm next to the levee dropped about three feet.”
The levee then spit a chunk of sod and dirt about 25 feet into the field, which was followed by a gush of water.
Stenzel said he looked into the river near the breach and saw a whirlpool about 12 feet in diameter with a vortex swirling about a foot deep.
“That'll raise the hair on the back of your neck,” he said.
Shortly thereafter, the levee collapsed in that spot, effectively sealing — albeit temporarily — most of the leak.
The corps, believing that the levee is destined to fail and flood thousands of acres, has pulled its crews from the site. And against the agency's advice, Ruch said, local officials continued to attempt repairs. The corps, however, does continue to work on a backup levee closer to town that it believes will hold and protect Hamburg.
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Volunteers try to protect Hamburg with sandbags: