Looking downstream in the Glendale Avenue Storm Sewer. This junction is indeed designed backwards.

Sisters of Mercy

Glendale Avenue Storm Sewer

Construction Details:
Tunnel excavated c. 1960s and lined with concrete panels. 1950mm south of Bloor, 2100mm near the lake.

Archival Material:

The drain we called Sisters of Mercy would have been built in the 1960s or early 1970s, and provided for the partial sewer separation of Earlscourt and neighbourhoods to the southwest (Emerson, Roncesvalles). There is also probably a combined sewer overflow somewhere in the upstream portion of the drain, but we didn't find it on our one visit.

With the construction of the Western Beaches Storage Tunnel, this storm sewer is now intercepted below the foot of Glendale Avenue, where it enters the topmost tank of the storage tunnel. The end of the explorable portion of the drain is a vertical siphon chamber near St. Joseph's Hospital.

This drain offers a very long walk, punctuated by two notable features. The first is a strange junction arranged backwards, so that following the flow downstream the main conduit actually forks. The second pipe is isolated from the main tunnel during dry weather flow, which appears to make it an intended overflow, relief tunnel, yet following this pipe around the curve quickly leads to an access chamber where further travel has been blocked off with metal stop logs. It's unclear based on maps where this might be, although it is possible that this strange tunnel runs down Roncesvalles, or that it provides a connection to another system further to the east. The second feature is somewhere way up the drain, perhaps in the vicinity of Bloor Street, where a small slide has been equipped with stepirons and metal railings.

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Michael Cook is available to speak to your organization about infrastructure history, lost creeks, current conditions, and opportunities for change in our management of and communication about urban watersheds, and to work with teams proposing or implementing such change. Get in touch.