I must say that most of the projects we try are a success, however once in awhile we find some that fail. I am not saying that it will fail for everyone, but it just didn't work for us.
We attempted the tin foil river that I saw on Pinterest, you're supposed to put the tin foil down a little "hill" and turn the hose water on and the boats would go down. Well, we did that, but our toys would not go down all the way. I even made several paper boats hoping that being light weight they would go down the stream, but nope.
In my opinion our "hill" wasn't steep enough and in my husband's opinion it was too steep, so the water was going too fast down and not accumulating to help the toys float.
The river's original idea failed, but the little man was happy as a clam, he played with it a lot and then just played outside with water, it was a beautiful warm day and the important thing was to have fun. So, thumbs up anyways because the tin foil river motivated us to be outside.