Army Corp of Engineers attempting Arkansas River operation for the first time since the 1990s

RUSSELLVILLE, Ark. —An operation on the Arkansas River is underway that the Little Rock district Army Corps of Engineers has not done since the 1990s.

Last month, a vessel grounded on a buildup of sediment between Ozark and Dardanelle that has slowly become a problem over the decades. Edmund How, Chief of Hydrology & Hydraulics U.S. Army Corps of Engineers Little Rock District, said the heavy flow upstream created the recipe to conduct a hinge pool operation.

“It’s really neat to kind of have the right conditions to solve a problem in a more efficient way,” Howe said.

By letting more water in, the Dardanelle dam is lowering the water levels to its north by six inches.

That doesn’t sound like a lot, but Howe explained that between the start of the operation on July 10 and the next day, the flow of sand at the trouble spot had more than tripled.  It is called self-scouring.

“Like a kid dumping a bunch of sand down a slide. I comes down and the slide kind of sticks out so they can hop off very easily. What we’re doing is effectively just taking the end of the slide and tilting it down a little bit further so that material keeps washing downstream into the deeper, much deeper parts of the channel,” Howe explained.

Before the lock and dam system was built on the Arkansas River, parts of the river would dry up and become unnavigable during parts of the year. The hinge pool operation ensures that the traffic can go in both directions and the water level stays the same.

Chief Public Affairs Officer of the U.S. Army Corps of Engineers Little Rock District Jay Townsend said they have to maintain a 9-foot depth channel for barges to travel.

“One 15-barge tow takes 870 18-wheelers off our interstate systems,” Townsend said.

The alternative solution would be dredging, but that is more costly to taxpayers and disruptive to commerce.

This operation is set to finish July 17, but rainfall and other factors upstream could change that.