I've written several posts documenting my attempts to capture more rain water by moving it from the barrels under my downspouts to remote/overflow barrels. One of my fears was that the overflow barrels are lower than the other barrels and that water from the higher barrels would just spill out of them. Well, that happened. I attempted to fix the problem by extending the overflow into the air. That didn't work.
float valve and fill the barrel from the top and then put a check valve at the bottom and have it feed back to the other barrels. (That is what I did for the barrel under my deck.) That's an expensive solution. I need to come up with something else. I may just end up moving this barrel to another location. I haven't decided yet. It's something I have to spend some more time thinking about.