KENT, Wash. -- A new flood wall is going up along the Green River as officials said as many as 5,000 people may need shelter this winter if it floods.

Video from Chopper 7 showed crews lining up giant white sandbags along the river Monday in the Horseshoe Acres neighborhood of Kent. After placing 3,000 sandbags on the bike trail they were wrapped in black plastic to form the wall. See video.

”When it goes it's going to go, you know. They say we could have anywhere from an hour’s notice to a couple of minutes,” said resident Ed Taylor.

Kent will use 20,000 bags to raise the 12 mile long section of the levy that runs through the city. Crews are working hard to finish the project by Nov. 1, before the rainy season begins.

WATCH IT: Giant Sandbags Go In Along Green River

“We can place one bag, one large bag and cover a 3- foot long area by 3-foot high area much, much faster than the small bags,” said Kent Construction Manager Peter Tenerelli.

The sandbags themselves are wrapped in thick black plastic, to protect them from the sun's damaging ultraviolet rays and to form a barrier to keep water from seeping between the bags.

“It's like having a life preserver you know, because anything, in the event there's a problem at least you've still got another alternative here to help keep it from getting so bad,” said George Green who has lived in the Green River Valley for 30 years.

WATCH IT: Residents Happy To See Work Under Way

"I would like to hope that we never have to use them at all, that would be the best situation," Tenerelli said.

The Army Corps of Engineers believes raising the levy by 3-feet should protect against the most likely flooding possibilities if they have to release more water than usual from the Howard Hansen Dam upstream.