In the mid-1920s, Robert Oliver Sweezey, son of a wealthy Trois-Rivières lumber merchant, became interested in the potential of the Fleuve Saint-Laurent (St. Lawrence River), particularly in the Beauharnois region. He soon became convinced that the river's flow was strong enough to compensate for a relatively low head (about 24 metres). As the project was too large for the technical means available at the time, Sweezey planned to build it in three stages. He also made plans, 30 years in advance, for the location of a future diversion channel along the Saint-Laurent and anticipated the rate of flow that would have to be reserved for it.
To dredge the Beauharnois channel efficiently, he invented the suction dredger that would henceforth bear his name. While he did not complete construction of Beauharnois generating station himself, he at least had the satisfaction of knowing that his invention was used for major projects at home and abroad, including Expo 67, the Louis-Hippolyte-Lafontaine Tunnel and dredging operations in the Greek port of Eleusis.