An enormous amount of work remains to be done to repair damaged levees along the Missouri River.
But at a cost of tens of millions of dollars, the U.S. Army Corps of Engineers has achieved a partial victory over the worst of the breaks that allowed floodwaters to spill into southwest Iowa.
Closure of three of the four most urgent breaches in southwest Iowa levees was expected to be done by Monday.
The cost of all four projects — a down payment on the overall bill — is expected to total more than $34 million.
More than 40 levee breaks occurred between Omaha and Rulo, and these four holes were targeted as priorities because of the infrastructure they protect, said Matthew Krajewski, readiness branch chief for the Omaha district of the corps. Behind those four levees are major industry, part of Council Bluffs, several small towns and key transportation routes, specifically Interstate 29 and a BNSF Railway line.
The holes have exposed the Missouri River Valley in southwest Iowa to flooding since mid-March. That's when a potent storm flushed massive amounts of snowmelt and rain runoff into area rivers with such force that flooding crashed through levees. A second round of rain in late May caused additional damage and delayed repairs to the levees.
In much of the area where the breaches have occurred, the Missouri River is flowing in a new direction — to the east instead of south — as if it is trying to cut a new channel, Krajewski said. That means the river has been heading overland, toward I-29, the BNSF rail line and the Iowa communities.
"Our immediate goal is stop the river from flowing the wrong direction, to keep it from going east, to make it go south again," Krajewski said.
Here's a look at these four priority breaches, from north to south:
» Protects parts of Council Bluffs, Highway 34, I-29, two energy plants, the BNSF rail line, a Google data center and the town of Pacific Junction. The 1,200foot gap in the levee cost about $6.2 million to fix. Repairs were completed last week. The work was done by Western Contracting Corp. of Sioux City, Iowa.
» Protects Bartlett, Iowa, and I-29. The 500-foot breach cost $8.5 million to close, and repairs could be finished as soon as Monday. The contractor is Newt Marine Services of Dubuque, Iowa.
» Protects Percival and Hamburg, Iowa, and I-29. It cost $7.5 million to plug this 520-foot hole. Repairs were to have been completed by this past Friday. The contractor is Western Contracting. Closure of this hole will lessen the amount of water flowing into Hamburg and ease the pressure on flood protections there.
» Protects Hamburg. This has been the most troublesome of the four breaches because it is at a bend in the river. The force of the water into that bend continues to eat away at the 550-foot gap in the levee, expanding the size of the hole. Now that the river has dropped enough to allow barge traffic, the corps can bring in barges filled with large rocks that will be dumped into the hole. Unlike sand, rocks will be more effective at withstanding the river's corrosive power. The original cost of the contract was $12 million. The work is being done by Newt Marine Services.
With work on these breaches well in hand, the Omaha district of the corps is moving on to other major projects. Next up: $44.2 million in work to plug two holes in the levee near Watson, Missouri. Those breaches are contributing to the flooding of I-29. The contractor is Weston Solutions Inc. of West Chester, Pennsylvania. The other breaches are not as high a priority either because they're not as large, the area they protect doesn't put as much infrastructure or people at risk or they actually function as escape holes for water to flow back into the river from flooded fields.
Additionally, water remains on some levees, so it's been difficult for the corps to assess damage in some areas. The damage to levees continues well downstream into Missouri, where flooding continues to be a problem. South of Rulo, a different regional office of the corps oversees levee repairs.
The corps is targeting March 2020 to close all breaches along the river between Omaha and Rulo, he said.
"It's a lofty goal, admittedly," he said. "But that's our goal."
These closures aren't final, Krajewski said. The holes are being filled to a minimum level of protection — roughly the equivalent of a 25-year flood — but not to the levee height or condition that existed before this spring's flooding. Additional work will be needed to do that, he said.
The breaches are being patched with river sand, either by dredging sand from the river or excavating it landside. Once the holes are patched the corps will "armor" them against the river's corrosive power, Krajewski said. Crews will do that by placing rock or clay over the sand to give the patch more resilience. As money and time permit, the corps will return and restore the levees to preflood conditions, he said.