KENT, Wash. -- Boeing is putting up massive new flood walls to protect its facilities of potential Green River flooding in the Renton and Kent areas.

Boeing spokesperson Bill Cogswell said when the company learned the Army Corps of Engineers may have to dump more water in the Green River this winter due to the compromised Howard Hansen Dam -- the company started working up a plan.

"The barriers went up around the Kent and Longacres facilities beginning of last week, September 28th, and construction continues right now and will for the next couple weeks," Cogswell said.

The walls are 12,000 feet of military-grade barriers designed to keep water out.

While bulldozers scurry to fill the temporary flood walls with sand, inside the Boeing facilities in Renton workers are also scrambling to move computers and flight simulators off the first floor to avoid damage if the barriers can't hold the river back.

"From Boeing's perspective we are taking this really, this risk really seriously in preparing for it," Cogswell said.

He said Boeing hasn't decided yet if it will keep some workers behind at the buildings - if indeed the flooding predictions become a reality.

While some details of its flood control plan are still being worked out, the aerospace giant has been contacted for advice by other major players like Starbucks, which also has property in the Green River Valley.

Boeing would not say how much it spent on the flood control walls or what it is costing the company to re-arrange buildings to get vital equipment off the ground floors.