Water Levels In Eau Pleine Were Too Low To Prevent Fish Kill

A citizens group is demanding solutions to another projected fish kill in central Wisconsin’s Big Eau Pleine Reservoir.

Record-low oxygen levels in the Mosinee area reservoir have homeowners and sportsmen bracing for another massive fish kill. John Kennedy of the Big Eau Pleine Citizens Organization says he worries that it’s going to be even worse than what happened in March 2009: “There [were] dead fish everywhere, washed up on shore. I guess what’s really disappointing is this appears to be a recurring event. This is a pattern.”

It’s a pattern that Kennedy thinks can be solved if water levels are kept at 60 percent full going into the winter months, a figure that was reached in a recent study.

“We came into winter at 50 percent volume. If we would have come into winter at 60 percent, we would have 20 percent more water. More water contains more oxygen, and you’re basically going to have more reserve.”

The water levels in the Eau Pleine and other Wisconsin River reservoirs are set by the Wisconsin Valley Improvement Company. Vice president of operations Sam Morgan says last year’s drought kept them from meeting the 60 percent goal.

“We had a pretty dry late summer and a really dry fall, and on December 1, rather than being at the 60 percent full level it was at the 50 percent full level, which we thought was pretty good considering how dry it had been.”

Morgan says if they had kept more water in the Eau Pleine, it would have hurt the rest of the river basin: “We would have had to have even lower flows in the Wisconsin River than we had, and they were already at critically low levels, essentially the minimum that we can do under our license.”

Morgan says the water quality problem in the Big Eau Pleine is impacted more by agricultural runoff than by the volume in the reservoir.