Dredging on Cedar River clears intake for Alliant power station

CEDAR RAPIDS - Excavators on a barge hauling construction equipment on the Cedar River in southern Cedar Rapids aren't working on the latest flood mitigation effort. Rather, they're dredging the river to clear the water intake system for the nearby Alliant Energy Prairie Creek Generation Station.

Alliant spokesman Justin Foss said the dredging - scooping up and removing earth from the riverbed - is considered a maintenance project for the 245-megawatt station.

'We in the last 10 years have had a lot of silting come up on the Cedar River. Our intake is getting full of silt, so we need to get out there and dredge to remove some of that,” Foss said Monday.

Water from the river is necessary for plant operation, he said.

The Prairie Creek station, 3300 C St. SW, uses about 40 billion gallons of water a year for cooling. Nearly all the water is returned back to the river.

Water used in the plant's boilers - used to create steam, which turns the turbines to produce energy - comes from the city.

Foss said dredging hasn't taken place near the plant's intake in about a decade, but added that recent high water events, including the 2008 and 2016 floods, could have expedited the flow of silt.

Last month, Alliant converted Prairie Creek's largest unit from burning coal to using natural gas.

With that switch, along with other work taking place at the station, Prairie Creek could save about 11 million gallons of water a day, Foss added.

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