Looking for title of childhood movie.?

So i watched this movie all the time when I was younger, but now I can't find it anywhere and can't remember the title. It was about a boy who fell into water, like at a treatment place or somethig, off a pipe and got sucked down into this whole other world. There he met some creatires, that I remember looking like kangaroos? And the typical battle of good vs. Evil ensued. Eventually he went home by going back through the water. I remember it being made by touchstone for some reason. Help me out? :)