Why does my cat deliberatly knock over his water bowl?

He never does this with the food bowl, which is the exact same kind of bowl. When I put water in his bowl, either set the bowl on the floor and pour it in or fill the bowl and set it down, the cat will come and seem to scratch at the side of the bowl or over the top and then smack it or tilt it so water runs out.

I have tried just putting a little water in the bowl. There's not so much to spill but then the water runs out and he yowls because he is thirsty. I am just wondering what he thinks he is doing? He hates stepping in the water yet he continues to spill it out.