I've called 911 twice for borderline issues and it played out both times just like you said - I said what I was seeing and to let me know if I should call a different line, they confirmed the issues were emergencies, and the rest played out like any other 911 call. Let the dispatcher decide.

On a related note, the valid reasons to call 911 are:

1. A danger to life, property or the environment

2. A crime in progress

3. Someone having a medical emergency who needs immediate assistance

4. A fire