680 is a lot of water! Just as one of the previous posters had pointed out, 680 is only 10 ft. lower than normal winter pool, and the pictures you all are seeing are pictures of the lake during a normal winter. This is not the end of the world or the end of tourism, this is usual stuff, just the only difference is that its going to look like this all year, not just for December-Feburary when noone usually pays any attention to it.
650 is still A LOT of water. An easy way to think of it is this, 650 is about 90 ft. below usual summer pool. C-Land is, on average, a 130 ft. deep lake. Therefore, if the Corp does take it down to 650, convential wisdom would tell you that C-Land would be a 40 ft. deep lake, on average. True, its a HUGE drop, but not the end of society! An average depth of 40 ft. is MUCH deeper than the average depths of Nolin (about 20), Green (about 25), Barren (about 25), Taylorsville, Barkley, Kentucky, and just about every other lake in Kentucky with the notable exceptions of Laurel, Dale, and Herrington. That being said, walleye survive in "relitivley" shallow Green and Nolin just fine, as do Striper in Kentucky, and the Ohio and Tennesee Rivers, that are more shallow than C-Land as well. Also, the summer heat will not zap the fishing. If the corp does take the lake to 650, they will have to keep the dam on full flow all the time, which will add current, and therefore, cooler, more oxygenated water to the lake.
Not only, at 650, will this still be a deep lake, but it will stay a HUGE lake. It will drop to about 20,000 surface acres, which is still, two times larger than any lake fully in KY. (Barren is second, it has a surface area of 10,000 acres.)
And just as they did at 680, they will extend the ramps at 650. Just a little more gravel and elbow grease will be needed.
All in all, this will be, if it does happen, a shock. But just look at the magnitude of this lake, and you will see just how this lake will survive.
To adress some other concerns, 610 is impossible, unless they remove all turbines from the dam. 610 is close to the old river channel, I think the tailwater is around 595, and I doubt they would ever drop it to 610 anyways. That would leave all the marina and the gas lines high and dry, which would produce another danger. Also, the old river channel, is undoubtedly, silted in, so at 610 the channel would probally be non-navagable, which is anohter reason I'm sure they wont drop it that far.