Associated Press, Published October 22 2013
Crews install 2nd of 9 Asian carp barriersCOON RAPIDS, Minn. — Construction crews are trying to install five gates at the Coon Rapids dam before winter sets in — as part of a $16 million improvement project to prevent Asian carp from leaping over the dam and reaching the upper Mississippi watershed.
The Minnesota Department of Natural Resources said a dead silver carp was recently found at a dam north of Winona, the furthest upstream the fish has been discovered in the Mississippi River.
The Star Tribune (http://bit.ly/H7bVHi ) reported Monday that two huge cranes lifted and slid the second of nine gates into place.
The nine gates, including six 97-footers, will replace aging rubber tube gates, which are less effective when it comes to keeping fish from passing during serious flooding. The crew is trying working fast before conditions get too icy and cold.
"We're on a tight schedule," said David Kost, project superintendent for contractor Edward Kraemer & Sons, of Burnsville.
Kost said the weight of the loads hoisted by the cranes is his main safety concern — especially on windy days. One of the cranes carries 150 tons. He said the cranes are stopped when winds gust to 20 or 25 miles an hour.
"Wind is always a factor," said veteran crane operator John Sinna. "Wind is nobody's friend."
Dennis Jonjak, Kraemer's project engineer, said the five gates and a new stilling basin below the dam should be installed by Dec. 1. Then, two coffer dams that divert water around the work area will be pulled out for the winter, and the dam will operate as usual until spring.
The 450-foot-long stilling basin at the dam's base will replace an underwater, concrete apron, Jonjak said. The new basin is made of 2,000 cubic yards of concrete and 450,000 pounds of steel rebar. It will sit on one-foot-deep layers of sand and rock and will be anchored by more than 230 H-beams in the river bed.
Information from: Star Tribune, http://www.startribune.com
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