The old rivers that still flow below

map - underground riversThey are called lost rivers, but for many in Leaside they are a rude awakening.

The most recent of these, and on rather large scale, is the formation of what’s mischievously been called the “largest swimming pool (skating rink?) in Leaside” at the site of the SmartCentre North development on the Vanderhoof-Wicksteed block east of Laird.

It is on the path of the post-glacial Walmsley Brook, a tributary of the West Don River, and you would think that the people at SmartCentre would have known about it.

According to Lost Rivers researcher Helen Mills, Walmsley Brook (named for John Walmsley, a settler in the north Leaside area, interestingly right there north of the Lea lands) “started as two small streams near Duplex Ave. and Alexandra Blvd., which joined together west of Yonge St. and flowed southeasterly to Mt. Pleasant and Broadway.

“From there it flowed in a generally southeasterly direction (past the Bayview and Eglinton intersection) to meet the West Don River in Ernest Thompson Seton Park, just north of Overlea. It was approximately six kilometres long and had 1 1/2 kilometres in two tributaries.”

Where Sunnybrook Plaza is today was a marsh, where, according to Jane Pitfield in her book, Leaside, “locals took loam for their gardens”. For RioCan at the Sunnybrook Plaza site where a major redevelopment has recently been applied for: There will be problems!

The other lost (or rather buried) river flowing through Leaside is Cudmore Creek, which started near Eglinton and Mt. Pleasant, ran through Mt. Pleasant Cemetery and now is completely buried, except for a small ravine beside the Bayview Extension south of the CPR mainline tracks. It crosses Bayview near Sutherland and is piped through the former ravine, which is now the much loved Sandy Bruce Park. Cudmore Creek was approximately 3 1/2 kilometres long.

Apart from the water courses themselves, Leaside has a shallow water table, a fact discovered by many developers in Leaside who try to excavate deep basements. Sump pumps are needed as a result.

Helen Mills runs interesting Lost River Walks.

About Geoff Kettel 219 Articles
Geoff Kettel is a community connector and advocate for “making places better”. He is currently Co-President of the Leaside Residents Association, Co-Chair of the Federation of North Toronto Residents‘ Associations (FoNTRA), member of the Toronto Preservation Board and Past Chair of the North York Community Preservation Panel. He writes a monthly column on heritage and planning in Leaside Life.