The canal’s history

The Soulanges canal has an important place in the development of navigation as well as in the expansion of maritime commerce in Canada.

Our regional museum presents you its history!

A river of tumultuous waters

The Soulanges canal has an important place in the development of navigation as well as in the expansion of maritime commerce in Canada. Its history is part of this great human and technological adventure that allowed, during the last two centuries, to go around the tumultuous waters of the Saint Lawrence river to reach the interior of the continent. In fact, at this point, the river is made up of a series of rapids formed by four slope breaks totalling almost 25.6 metres of difference in level over a distance of 12.8 kilometers.

Le Trou rapids at Pointe-des-Cascades (before 1893)
Source : ©Centre d’archives de Vaudreuil-Soulanges, Fonds Pierre Clément, P-20-220

1840 – 1899

At the end of the 19th century, the decision of building a new canal is becoming inevitable. The need to replace the Beauharnois canal with a larger one is becoming more pressing, since the expansion of maritime commerce now requires bigger ships. The construction of the Soulanges canal lasted for 7 years. It started in June of 1892, and welcomed its first boat on October 9th, 1899. It’s quite a tale, one which forever transformed the landscape of the region and the way of life of its population.

Impact on the population

The 23.4 kilometer route proposed by Thomas Monro, the engineer in charge of the work, will not be without consequences for the population and the four municipalities along its route. Pointe-des-Cascades and Les Coteaux, located at the mouths of the canal, will undergo major physical transformations, including several building demolitions. Many landowners will see part of their land expropriated, and many farmers will have to make long detours to the nearest bridge to access the most important part of their fields.

Aerial view of the Soulanges Canal at Pointe-des-Cascades (first half of the 20th century)
Source : ©Centre d’archives de Vaudreuil-Soulanges, Fonds Pierre Clément, P-20-124

A big step in technological advancements

Construction of the Soulanges canal turned out to be a longer and more arduous task than what the preliminary studies had shown. Many factors contributed to the complexification of the works, significantly delaying its opening. One of them was the nature of the soil itself in Soulanges, against which the workers and contractors fought tirelessly against for seven years. To meet deadlines and to face the many intangible factors plaguing the construction, over 1 200 workers could be on site at the same time, distributed along this huge construction site.

Workers riprap the banks of the Soulanges canal (circa 1897)
Source : ©Centre d’archives de Vaudreuil-Soulanges, Fonds Pierre Clément, P-20-215

The following steps

Although anticipated, the presence of a large number of stones along the entire route, as well as the instability of the loamy soil resting on a bed of sand, caused considerable problems. Preliminary reports had underestimated the consequences of this geological phenomenon and frequent screes would complicate the works. In the sections going through the municipalities of Les Coteaux and Coteau-du-Lac, the presence of soft and oily blue clay would cause frequent landslides. Engineers in charge of the contruction site went ahead with flattening out and rip-roaring the canal shores in strategic places. Concrete dykes, used to solidify the walls of the structure, were placed along the course.

Mechanical shovels digging in clay soil on section 9 (Coteau-du-Lac, September 24, 1895)
Source : ©Bibliothèque et Archives Canada, C-20869

An illuminated canal

The most remarkable technological innovation that was used at the Soulanges canal is without a doubt hydroelectricity. Electrification has made it possible to drive the motors of all mobile structures such as locks, swing bridges and weirs, reducing the number of employees needed to keep the canal running smoothly. Electric street lamps, distributed along the path, now allowed for ships to go through the canal day and night.

The illuminated Soulanges canal (after 1902)
Photo taken from the railway bridge at the number 5 lock in Coteau-du-Lac
Source : ©The Canadian Engineer

“Petit Pouvoir”, the Cedars’ powerhouse

This hydroelectric power was provided by a little power plant, built in 1899 by engineer Thomas Monro, located at the meeting point of the Soulanges canal and the rivière à la Graisse in Les Cèdres. This location, chosen because of its six-meter drop between the canal and the river, ensured sufficient hydraulic force to turn the turbines of the power plant. Although designed for an industrial purpose, the architecture of this building stands out by its “castle” style that was in vogue in the 1870s. It can find in a series of hotels, such as the Château Frontenac in Quebec City.

Le Petit pouvoir”, the hydroelectric power station on the Soulanges canal (October 4, 1910)
Source : ©Bibliothèque et Archives Canada, C-63798

The end of an era

The ever-increasing dimensions of the ships going through the canal, as well as their increased numbers will mark the end of this installation. As the size of the locks could not meet these requirements indefinitely, the last ships crossed the canal in the autumn of 1958. The official inauguration of the Saint Lawrence Seaway, in use today, on June 26th, 1959 definitely sealed the fate of the Soulanges canal, considered for a long time one of the biggest feats of engineering of the 19th century in Canada.

The end of an era(July 30th, 1955)
Photo courtesy of Mr. Bernard Prieur
Source: © Centre d’archives de Vaudreuil-Soulanges, Fonds Canal de Soulanges, 103


Texts and research : Musée régional de Vaudreuil-Soulanges.

Further reading: Sébastien Daviau and Édith Prégent. The Soulanges Canal (1899-1958): a technological and human adventure. Vaudreuil-Dorion, Musée régional de Vaudreuil-Soulanges / Virtual Museum of Canada – Histoire de chez nous, 2010.

François Cartier. Canal de Soulanges. D’un défi à l’autre. Les Coteaux, Société de développement du canal de Soulanges/ Musée régional de Vaudreuil-Soulanges, 1999.