The Omaha Airport Authority is making significant progress in its efforts to protect Eppley Airfield from the flooded Missouri River, officials said Thursday.
Nearly all of the 70 pumping wells designed to control rising groundwater levels are constructed, and 53 of them are pumping water into the river or the airport's storm water drainage system. Well construction is expected to be completed by Wednesday.
"We've seen some great results from bringing these online," said Dave Roth, head of the airport authority's engineering wing.
River levels surrounding Eppley's levee system have stabilized. The river is 7.42 feet from the top of the levee on the airport's south end and 9.55 feet from the top at Eppley's northern boundary.
But much of the airport authority's massive flood-fighting effort is focused on the pumping wells, aimed at keeping the water table from rising and threatening airport infrastructure.
As large amounts of river water press against the federally constructed levee, the water will naturally force itself anywhere possible to relieve the pressure. That means water will seep into the surrounding soil, thereby elevating underground water levels below the airport property.
If airport officials did nothing, computer models show, groundwater levels would rise to a point where water would bubble up and flood the runways and terminals — along with the area adjacent to the river. Pressure wrought by elevated groundwater levels also creates sinkholes and sand boils, which occur when river water forces its way under a levee and percolates up on the dry side, that threaten airport property.
So far, the pumping efforts have dropped water table levels by approximately eight feet in areas around the pumping wells.
The bill to protect Eppley was last projected to reach at least $15.5 million.
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