Starting in the 1920s, plans began for damming the St. Lawrence to build a massive hydro-electric power plant and an artificial body of water that was navigable for ocean-going ships. This would bury much of the local landscape under an artificial lake. As negotiations between governments continued for two decades and more, local land values plummeted as a result of the project's apparent inevitability. By "Inundation Day", on July 1, 1958, which was also the Dominion Day ( Canada Day ) holiday, many landowners complained that market value compensation was insufficient, since the Seaway plan had already depressed property values in the region. These complaints were never addressed, a sad parallel to the poor treatment the locals had been given more than a century earlier.