Flowing water washes against the hulls of an old, landlocked Navy submarine and minesweeper.
It laps against 6,000-pound steel floodgates at Omaha's Lewis & Clark Landing.
It rises more than halfway up the sealed, reinforced door of a riverfront pumping station.
The Missouri River is flooding scores of lowland dwellings, covering highways and drowning cropland for hundreds of miles. The flood is the river's largest in 113 years of records.
But behind the levee protecting Omaha, the city's low-lying transportation, commercial and industrial sites remain relatively dry.
On the Iowa side, while seepage from the high water table continues to plague some homeowners and businesses behind the Council Bluffs levees, no floodwaters are spilling into the city.
This despite two months of unprecedented water against the earthen berms — with an estimated six to eight weeks before the river is back in its banks.
Flood fighters say part of that success has been because of the mobilization of 35 geotechnical, civil and hydraulics and hydrology engineers from U.S. Army Corps of Engineers offices across the nation. They came for temporary duty at the hub of the action, the Omaha District that spans parts of Nebraska and five other states.
"We have a wealth of flood-fighting experience here,'' said Dick Taylor, the Omaha-based engineer coordinating the levee surveillance teams.
The Mighty Mo is providing a dynamic summer graduate course in the design, maintenance and operation of river levees for engineers from Alabama, Alaska, California, Illinois, Mississippi, Missouri, Oregon, Pennsylvania and Washington.
Omaha's clay levees and concrete flood wall were built in the 1950s.
"The levees are doing what they were intended to do,'' said Tony Deus, a corps geotechnical engineer from Sacramento, Calif., who arrived more than a month ago. "I'm not saying that's surprising, but it's notable, given the duration of the flood and how high the water is.''
In Sacramento, Calif., Deus designs and analyzes 1,700 miles of levees in parts of eight states, from California's Central Valley to the Rocky Mountains of Colorado.
"Now I get to see this stuff in action. See what works and what we need to improve upon,'' he said.
Part of Omaha's success, he said, is free-flowing communication from everyone fighting the flood.
Deus talks with contractors leading the defense of Eppley Airfield, the region's largest airport. He talks with levee patrols. He talks with guards at the Omaha Correctional Center, where a little seeping water is allowed to pool between the prison fence and the levee.
"Making sure that everyone knows what's going on at all times is the most important part in the flood fight,'' he said.
Deus is part of the corps' levee surveillance team, led by Omaha's Taylor and Terry Matuska, a levee design engineer.
They work closely with Bob Stubbe, Omaha public works director, and Gordon Andersen, a public works manager who coordinates the city's levee maintenance. The four toured the city's levees last week on the eve of the corps announcing its timetable for reducing releases from the upstream reservoirs.
The levees don't know it, but the end of flooding is in sight.
"We've made it through some very high river levels, and we haven't found any leakage from the sides of any of these levees,'' he said. "That's a great thing.''
Levees in Council Bluffs are subject to similar surveillance, with help from the corps.
Omaha's 13-mile levee is lined with scores of wells and pumps hurriedly installed to help return seeping floodwater to the river. Hoses and pipes snake across the tops of the berms and walls.
To keep seeping underground water from flooding Eppley, about 100 million gallons of water is pumped out of the site daily by 70 new wells along the levee. That's roughly three-fourths of the water Omahans use on an average July day.
On a smaller scale, a supplemental diesel pump draws 200 to 500 gallons per minute of orange-tinted seeping water — colored with iron oxide — from old wells at the base of the levee north of the airport.
If that pump were to shut down, the wells would instantly fill and start flooding inside the levee, Matuska said.
Taylor said considerable amounts of water seep under the levee in places, but engineers prevented failure by building sand berms at the base.
The berms consist of a sand layer — and sometimes a fabric liner — topped with crushed limestone. That allows water to percolate through the levee while the integrity of the structure is protected by preventing soil from eroding.
Six sand berms totaling nearly a mile in length were completed at Eppley in July. A new sand berm was built last week near the correctional center.
Taylor said the Omaha levees look good.
"Any time you have water on levees there's some level of distress. But they've been holding up real well,'' he said. "The city's been proactive in getting out there and pumping relief wells or getting (seepage) blankets and seepage berms in place.''
Andersen said nothing has been better for maintaining the levees than on-site inspections.
"We catch the problems before they become big,'' he said.
Omaha also uses a high-tech tool. A police helicopter equipped with an infrared device has provided aerial surveillance of the levees since floodwaters started rising. The device identifies pooling water pushed to the surface based on its temperature.
Deus said he will have much to share in a post-flood briefing to Sacramento District colleagues.
"The levee inspections, the nice (relief well) construction at the airport ... we'll use it all as a baseline for what we're doing everywhere else in the corps and say this is what worked.''
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