Welland Canal and crossings are numbered from north to south. The following illustration depicts the profile of the Welland Canal. The horizontal axis is the length of the canal. The vertical axis is the elevation of the canal segments above mean sea level. If assigned by the St. Lawrence Seaway Authority. The original bridges across the fourth canal were numbered in order. Numbering was not changed as bridges were removed. Welland Canal The Welland Canal is a ship canal in Ontario, Canada, connecting Lake Ontario and Lake Erie. It forms a key section of the St. Lawrence Seaway. Traversing the Niagara Peninsula
First Welland Canal didn't start until July 1825. Wherever possible, natural waterways were used, but this was not possible for the construction of the canal between Port Robinson and Allanburg. In what was called the Deep Cut, a channel over three kilometers long was cut, sometimes as deep as 20 meters. No less than 750,000 cubic meters of earth was removed. Prior to the construction of the Welland Canal, the main settlements in the area were located along Lake Ontario and Niagara River, as the interior of the Niagara Peninsula remained hard to reach and rural areas, if that. As the construction progressed,