Problem with Shell Rock River dam at Rockford - KWWL - Eastern Iowa Breaking News, Weather, Closings

Problem with Shell Rock River dam at Rockford

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FLOYD COUNTY (KWWL) -- Another Iowa dam is in danger of failing.  Water started rushing under a small dam on the Shell Rock River in Rockford Tuesday afternoon.  And the possible breach of this dam is a scary thought for many, after what recently unfolded at Lake Delhi.

The small dam over the Shell Rock has been in place since the 1870s.  But now, it's in danger of being washed away.

A whirlpool that's formed on the top of the dam is the cause for concern.  It's sucking water down into the dam structure, and with enough pressure, that could cause the dam to give way.

"As the water runs through, it will irrigate and take away the silt that is actually a protective measure on the back side of the dam.  So the more of that silt that's taken away, the more chance there is of the water being able to erode the structure below," said Randall Schweizer, with Rockford Public Works and the city's police chief.

Even if the dam does fail, it will not result in the kind of catastrophic flooding that resulted following the dam breach at Lake Delhi.  The river levels would only rise modestly.

"Anything downstream would be 2-4 feet and then when you get to Marble Rock, which is south of here, maybe 1-2 feet.  And in Greene, further south, a foot or less," Floyd County Sheriff Rick Lynch said.

In fact, since the dam's not needed for flood control, county officials actually talked about having the dam removed a few years ago.

"You'd have a lot of people that wouldn't like it to be gone.  But it's old and it's inevitable.  And it takes a lot of somebody's money to keep it repaired, too," said Glenn Biggs, a life-long Rockford resident and dam observer.

But for now, it remains uncertain if or when the dam may break. 

The Rockford dam last underwent an extensive inspection back in 2003.  Inspectors did find potential problems with it then.  But because the dam doesn't hold back that much water, officials did not find it necessary to repair it. 

Right now, recreation on the Shell Rock River is not being restricted.  But the public is asked to stay away from the dam and behind posted barricades.

KWWL Reporter:  Kera Mashek

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