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
Welland Canal first canal ran from Port Dalhousie, Ontario on Lake Ontario south along Twelve Mile Creek to St. Catharines. From there it took a winding route up the Niagara Escarpment through Merritton, Ontario to Thorold, where it continued south via Allanburg to Port Robinson, Ontario on the Welland River. Ships went east (downstream) on the Welland River to Chippawa, at the south (upper) end of the old portage road, where they made a sharp right turn into the Niagara River, upstream towards Lake Erie. Originally, the section between Allanburg and Port Robinson was planned to be carried in a subterranean tunnel.