By David Hendee
OMAHA, Neb (Reuters) - At 7:30 every morning, seven days a week, Omaha airport officials meet with contractors to talk about water -- how high is it, and what is being done to keep it away from runways and other facilities.
They talk about the levee protecting the airport's 2,700 acres -- and where the swollen Missouri River is in relation to the levee's top. They talk de-watering wells, berms, sandbags, sandboils and sinkholes. And they talk weather, because a heavy rain could cause flash flooding on already saturated ground.
"It's been very interesting," said Steve Coufal, executive director of the Omaha Airport Authority. He said this is the first flood-fighting initiative he has seen in his 8 years at the airport. "I don't expect another one. One is enough."
Heavy rains and snow melt have caused flooding on the Missouri River, forcing communities from Montana to Missouri to reinforce levees, and thousands of residents to flee the rising waters.
Flooding has already forced the Fort Calhoun nuclear power plant north of Omaha, which closed in April for refueling, to remain closed until the water recedes.
The river has reached 36 feet at Omaha, topping 30.26 feet in 1993, its second highest-crest. Its highest crest was 40.2 feet in 1952, before upstream dams were completed.
Eppley Airfield, which has 90 flights a day and contributes $745 million a year to the economy of Nebraska's largest city, is determined to stay open. By the end of August, the airport expects to spend about $15.5 million on flood preparations, according to Coufal.
"Our objective has been two-fold, which is to protect assets and to keep air operations normal," Coufal said.
The airport already has 235,000 sandbags placed at strategic points around the terminal, concourses, electrical boxes and navigation aids, Coufal said. More are ready to place as needed.
Contractors also are installing 70 de-watering wells along the airport's perimeter, sunk 90 feet deep, to stabilize water levels to prevent sandboils and sinkholes. The airport plans to have them all operational by mid-July, with some water running to the storm drainage system, and the other going back into the Missouri, Coufal said.
The airport had three pumping stations before the flooding started, with one pumping under the levee and two over. Pipes were relocated so that all three pump over the levee, Coufal said.
The levee top is 6.2 feet above the river's water level on the south side of the airport, and just under 8 feet above water on the north side, as of Saturday. Flooding is expected to continue in the area for another two months.
Both the city of Omaha and the airport authority have "done a tremendous job" of repairing the levee as the flows continue to go up, said Kim Thomas, spokeswoman for the U.S. Army Corps of Engineers, Omaha District.
That includes installing "seepage berms" on the dry side of the levee, made of a special fabric covered by sand and gravel, to allow water to seep through. Thomas explained this helps safeguard the integrity of the levee.
The Corps is monitoring rainfall on tributaries into the Missouri River south of Gavins Point Dam in South Dakota, which could worsen flooding, Thomas said.
So far, air operations at Eppley have remained normal. If Eppley is closed by flooding, airports in Lincoln, the Nebraska state capitol 50 miles south of Omaha, and Des Moines, the Iowa state capitol about 120 miles to the east, are preparing to receive some Omaha flights.
(Additional reporting by David Bailey in Minneapolis; Writing by Mary Wisniewski; Editing by Greg McCune)