It doesn't just add Gotham-City-like ambience or the opportunity for a Marilyn Monroe moment; steam grates serve a real purpose in urban life.
According to a spokesperson with the City of Vancouver, the steam you see emanating from the maintenance hole covers on Downtown streets is caused by water being discharged into the pipes and coming into contact with outside air.
We typically see the steam more often during cooler temperatures.
Do different grates serve different purposes?
There are a number of different types of grates and access covers across city streets that indicate the below utilities including water, sewer, power, and electrical, etc.
"Round or rectangular maintenance holes are typically linked to underground utilities (e.g. water, sewer, electrical, etc.)," explains the city, "whereas grates are typically related to vented underground transportation infrastructure."
For instance, the large rectangular grates on streets like Granville—you know, the ones that will trap a stiletto (unless you're Rihanna)—are a part of the SkyTrain infrastructure, providing ventilation in and out of the Canada Line tunnel.
