Today, one year ago, the lake reached its lowest point of 2015. I thought we had reached the lowest point in this year's annual drawdown last week, but it appears that Ameren has been releasing a respectable amount of water in anticipation of the coming 4 inches of rain. The effect has been to see lake levels lower than they have been in five years when the lake reached a minimum of 653.69' on March 31, 2011. The lake is currently at 653.35' and dropping.
With a sustained discharge averaging over 25,000 cfs for the past 24 hours the lake has dropped a full foot. This is actually great insight to just how much water must flow out to obtain such drops when there is very little surface water contributing to lake levels. It's been very dry in the area so nearly all of the lake's water renewal lately has come from its major river and stream sources, which on average run about 10,000 cfs.
I don't like rapid tide-like changes in lake depth, it seems to mess with the fishing. I respect what Ameren is trying to prepare for, but I think they may be overreacting a bit. I don't think four inches of rain is going flood a lake that was already nearly six feet below normal operating levels.
Then again, they may just be trying to make the paddle-fishing interesting below the dam. ;-)