Concrete doesn't bend like that without failing. This is an imaging defect. Otherwise, at minimum, you would see water spewing out through numerous fractures in the concrete.
.
UHMMM. You notice something strange about that photo?
Take a look at the color of the water. Unless thats an older photo, that water should be BROWN.
BTW..the shadow on the water from the dam...its distorted also!
That is the warped (distorted) satellite images that I was referring to. The actual dam does not look like that when photographed by local cameras.