Great concept, but it looks out of focus.
This could be a more interesting abstract composition if the pebbles occupied more of the bottom area and the water less (rule of thirds)... or vice versa, to concentrate on the ripples in the water.
It looks dirty, and slimy. Like the same color of sewage coming out of the ground. I hope its not, that wouldn't be good. But it does look dirty at the top in the water, and it turns me off. I hope this comment helps, I dont mean to be over-critical.