High Park Trunk Sewer
High Park Trunk Sewer
Year of Construction:
Small brick arch installed both in cut and in open air and then buried in fill.
Also Known As:
The High Park Trunk Sewer was installed on the northern border of High Park in 1914 as part of a programme of ravine filling and service provision to pave the way for residential development north of Bloor Street and west of Keele Street. Photographs in the archives show the structure of the sewer exposed in open air near Clendennan Avenue, waiting to be buried along with a significant portion of the Spring Creek ravine.
The trunk sewer runs from just east of Jane Street beneath Bloor West to the vicinity of High Park Avenue, where it turns southeast into the park on its way to the now disused Parkside Stand-by Tanks. It begins as a low rectangular box, passing down a series of steps east of Runnymede, and then grows to a 2m tall brick and concrete arch east of Clendennan Ave., where it joins with a sub-trunk from the north that services the area around the Western Technical School. Somewhere near High Park Avenue, it also receives a side-connection that serves the massive conglomeration of apartment towers northwest of Bloor and Keele, a concentrated volley of sewage that smells heavily of chlorine and ammonia from the towers' laundry rooms.
In the northeast corner of High Park, a small pipe diverts the flow from the trunk sewer southeast to the High Level Interceptor. Here the trunk sewer used to overflow during rain events into an open gallery on the north side of the tanks. With the construction of the Mid-Toronto Interceptor in the 1970s, the old overflow for the trunk sewer was bulkheaded about ten metres west of the tanks. While plans originally called for a new diversion to be built to route the sewer's flow to the MTI, this does not appear to have been carried out. What likely happened was that planners determined the removal from the High-Level of the flow volumes delivered by the adjacent Earlscourt trunk sewer (which ran down to the tanks from Keele Street and now passes into the MTI) was sufficient relief for the High-Level.
Overflow for the High Park Trunk Sewer is now provided by a tall side-flow weir and adjacent concrete shaft in the diversion chamber. Overflows drop about fifteen feet into a modern concrete conduit that deliver them to the Parkside Drive Relief Sewer.
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.