Northern Light
Superstar
So while our building (we live in the area) has separate sanitary and storm sewer systems (including a storm water management cistern) with separate lines going out of the building - that would mean that both our sanitary and storm sewer lines could be connecting into a City combined sanitary and storm sewer line. If so - kind of defeats the purpose of having separate lines throughout our building - but it does position things should the City get around, at some future date, installing separate storm sewer lines in this area.
I don't know your address or the exact choices made for it.
I can tell you that for newer buildings the City has required on-site stormwater management.
That means the requirement to minimize it and then to not let excess flow overload the combined/sanitary sewer system (on-site storage).
This means a building approved today (or in recent times), in theory, should not be a contributor to overflows.
If the water is released into the system later, it can be fully treated. Overflows only occur during storm events.
I haven't had a chance to look up all the images I do have for the sewer system.
But I found this one online that gives a general sense of things. This is from ecospark.ca