There are many well functioning local governments in the United States.
The US is a big country both in terms of habitable land and population, with almost 325 million people (Canada technically has more land, but since most of it is uninhabitable, they don't have to worry about plumbing it). You've read about ONE city where the mismanagement was so severe that the water became poisonous. I'm sure it's not the only one, but I'm also sure this happens in countries that aren't America sometimes too.
I'm not a civil engineer but from what I hear, Flint's water problem is nearly impossible to resolve and would practically require a complete extraction and replacement of the city's infrastructure, which isn't really possible without destroying the city anyway, since there are buildings and roads and stuff on top of it. Of course, it's politically incorrect to admit that, and politicians and bureaucrats will probably keep pretending like they are going to do something to resolve it to try to keep public anger at bay, and just hope the city empties out before anyone notices that it's been 30 years.
Maybe that evaluation of the engineering issue is incorrect, it's just what I've read; as above, I'm not a civil engineer so I don't actually know. But this is not just a simple matter of cleaning up a minor bacterial contamination. Minor contaminations of that type occur and get cleaned up all the time without anyone taking special notice (except the citizens affected by the boil order).
I understand it's fun to throw rocks at the big guy, but your comment is not representative of life in the US. If we had such a hard time providing basic services like water and our neighbor to the immediate north didn't, things would look a lot different.