Where's all the water gone?

I had an hour between 5 and 6 PM today, so I decided to pay a quick visit to carp cove. Upon my arrival, I noticed just how shallow this cove had become--about a foot deep in my usual spot. Not only so, but the water was clear enough to see the muddy bottom, and there wasn't a carp in sight! I catapulted out some bait anyway, hoping to lure some curious fish in from further down the cove with the sound of corn hitting the water. After a half hour with no visible carp, no swirls, etc, I realized that they probably wouldn't venture in this shallow so early in the afternoon. Just this past Sunday they were in the same place in force between 6:30 PM and dark, but not today--at least not between 5 and 6 PM. I had also planned to catapult out some floating trout chow and see if I could entice the carp to feed on the surface, but, since they weren't around, I only fed a few turtles. I guess if I want to fish earlier in the afternoon than an hour or so before dark, I will have to move down the cove toward where it joins the main lake. Hopefully the deeper water will harbor carp even during the heat of a sunny summer day. I am also curious to plumb that area with a marker float and lead to see just how deep the main lake is there. If memory serves, once when rowing around this lake in a john boat I found water around six feet deep there (by sticking an oar down in the water and touching the bottom)--as far as I know, the deepest part of this lake. Most of the areas closer to my house are only 3-4 feet deep in the middle.