ANAMOSA, Iowa (AP) — Divers have been called in to repair a washout on a dam in Anamosa caused by flooding on the Wapsipinicon River in 2008.
The dam, which generates electricity for Alliant Energy, is owned by North American Hydro of Neshkoro, Wis.
“It needs to be fixed. If left untended, the dam would have eventually washed out,” said John Dirks, of Morley, who operates the dam for North American Hydro.
Dirks told The Gazette that if it had failed, the results would not have been catastrophic, he said. The Anamosa dam is much lower and holds back less water than the dam at Lake Delhi, which washed out in July, draining a 9-mile-long lake.
Divers who inspected the Anamosa dam last year confirmed the washout.
The repairs, which began earlier this week, are being done by Underwater Construction Corp., of Stevensville, Mich.
“With the river higher than we’d like, working conditions are not ideal, but this has got to be done,” Dirks said.
Boards were placed on top of the dam to divert the current away from the divers, who are working in water about 15 feet deep.
Concrete is piped under water to the divers, who pump it into large cloth bags to build concrete blocks, said Rory Alsberg, repairs and maintenance manager for North American Hydro.
The blocks will be pinned to the bedrock and to each other with iron and then covered in concrete, he said. The divers works in pairs and are in the water for no more than three hours a day.
Information from: The Gazette, http://www.gazetteonline.com/