Don Mouth History Lesson

There has been considerable discussion about where the mouth of the Don used to be and what should be done with it today. This is all part of the Don Mouth EA process. In a recent email discussion, many thoughts about the early history were discussed but the most interesting one comes from Michael Moir, an archivist working at York University. I am reprinting his remarks here.

"The Don River has emptied into the Inner Harbour ever since Joseph Bouchette did the first survey of Toronto Harbour in 1792 (a copy of this plan is available at the City of Toronto Archives). I am not a hydrologist, but my hunch, after reading Sandford Fleming's articles on the formation of the harbour published in the Canadian Journal during the 1850s, is that the lake currents, which travel from the east to the west across Toronto's waterfront, eroded soil from the Scarborough Bluffs. As the current slowed when it ran into the outfall of the Don, silt was deposited over time, forming the 1,300-acre marshland known as Ashbridge's Bay and the sandbar that eventually became the Toronto Islands.

The Don emptied into the naturally formed harbour until the late 19th century, when channelization of the lower river brought the mouth of the river south into Ashbridge's Bay. Unfortunately, human sewage and cattle manure from the byres of Gooderham & Worts also emptied into Ashbridge's Bay, leading to much sickness. The City undertook the construction of the Coatsworth Cut and Keating's Channel in the 1890s in order to create water flow through Ashbridge's Bay so that the human and animal waste could be diluted or swept into the waters of Toronto Harbour.

When the Toronto Harbour Commissioners (THC) undertook the development of waterfront in 1912, the initial plans of its engineers called for a return of the Don to more or less the original course of its mouth as it entered Toronto Harbour. This approach meant that the river would have been diverted southwest from a point along the north-south section of the channel, which would have encroached upon the refinery of the British American Oil Company (located on the north side of Keating's Channel, west of the existing mouth of the Don). Although the THC had powers of expropriation, it did not use them in this instance, perhaps because of the costs involved. The THC changed its plans and decided to follow the route of the existing north-south channel, construct concrete dock walls along Keating Channel, and fill in the waterway lying east of the elbow formed at the junction of the Don and the Keating Channel.

Technical drawings and textual files regarding this planning process can be found among the THC archives currently administered by the Toronto Port Authority at 60 Harbour Street. There are no public hours to access this collection, and you would have to contact Mary Perisic, Manager of Administration at the TPA, to find and use this material. Please let me know if I can be of any further assistance."