I work for a city and my department suffers from a lot of issues, primarily incompetants and harrassment from upper management and colleagues. Now, we have attempted to go to upper management and even human resources to solve the problem, but have failed. I finally decided to write city council, because I heard someone from another city did so and they helped them. I explained to the council that I went through the proper channels, going to management and human resources and it didn’t help. It wasn’t a hate letter, but moreso a letter addressing concerns. I wrote about a team leader, manager, and assistant director. I’m just a regular worker. I didn’t straight complain about them all, I noted the good things about them and the bad things. My question is can I get fired or harrassed for trying to make the workplace a safer and healthier place to be at?

Illegal though it is, yes you probably will. The higher ups have low tolerance for boat rockers.
You are rightly or wrongly perceived as a pain in the ***!
By the fact you have not found a friend to agree with you, they may be right. You are an example of someone trying to manage from the bottom, without seeing the full / big picture, or understanding the full instructions from above
Ever hear the expression, “: don;t make waves.”
Unless you are civil service, you don’t want to get the wrong person pissed off at you.