I don't know whether to judge the images on the basis of conforming to the theme or simply on their individual merit. I suppose it would be best to consider both.
The little girl drinking water has a message that I have never seen before. Living with the affluence we have here, the message I'm getting is that the little girl probably cannot drink the tap water and must purchase bottled water to be safe. We will come to that situation here as well, sooner or later.
The Niagra shot seems to be the opposite - it seems to be saying that you can use all the water you want, even recklessly, because there's an unlimited supply. I am really surprised at that coming out of Montreal, because I know from personal experience that the people of Montreal are very, very environmentally conscious and put a high priority on their water.
The images themselves, taken just as photographic images are both very good. The Niagra scened is much more dramatic and better executed than the shot of the little girl. The very distracting hot spots are the problem. That and the fact that the color balance seems un-naturally warm. I think a gray card Custom White Balance is in order for that lighting.
Both shots are real attention getters, and I enjoy them both.