By Hamutal Dotan

Ask Torontoist features questions posed by you, and answered by our elite team of specially trained investigative experts (also known as our staff). Send your questions to ask@torontoist.com.

Reader Tyler Kerr asks:

Why is there always a tiny river running down McCaul and turning east onto Queen? It mostly stays in the streetcar tracks, and once or twice I’ve been able to see its source: somewhere inside wherever that streetcar turnoff on northbound McCaul leads. I can’t be the only person wondering why that little stretch of Queen West is always wet.

Torontoist answers:

This is not a coincidence, nor is it the symptom of a persistent leak. The water is injected into the tracks for lubrication, to lessen the noise of the streetcars’ wheels as they round the corner. Oil or some kind of grease might seem more natural choices, but while these do lubricate effectively they can also build up on the roadway and damage car tires, and so in higher traffic areas water is sometimes used instead.
This stream may eventually run dry, however. We consulted with keeper-of-the-TTC-lore Steve Munro, who told us that the TTC has been shifting to wheel lubricators (rather than lubricating the tracks), which use far less grease and therefore are safe for automotive traffic. The McCaul tracks are slated for reconstruction some time in the next few years, at which point the TTC may install a wheel lubricator and the river of water will be no more.