We camped at Victoria Bryant State Park in Georgia a few weeks ago and I swear the squirrels were doing it on purpose. We would be sitting, all relaxed and then "pow, pow, pow" on the top of the trailer followed by a couple of squirrels running off through the tree branches. I could swear they were laughing.
Lake Lanier is currently (as of 9/30/2016) 6.6 feet below normal. I've seen it as much as 15 feet below normal. The Corp always drops the lake some during the Summer both to keep the river full and to make room for flood control to absorb spring rains. but in years of drought it gets much lower. Check out this website:
Lake Lanier Water Level
At the bottom of the chart, click on the box for 2011 - and that wasn't the worst year in recent history by far - that would have been 2006.
That's why Georgia, Alabama and Florida have been in court for years fighting over "Water Rights".
But it's still a pretty lake - and very deep. Even at its lowest levels it's still great for recreation and fishing.
Of course I know for you folks out west, like on Lake Powell, a few feet down is nothing.