The construction and operation of the First, Second, and Third Welland canals

The Welland canals are features of great Canadian renown in terms of engineering, as transportation arteries, and through their contributions to industrial development and urban achievement. Their instigator was William Hamilton Merritt, a St. Catharines businessman. Functionally, they must be perceived as an inland extension of the St. Lawrence system of waterways. These contributions began when the First Welland Canal opened in 1829, and extend continuously up to the present. The First Welland Canal, fed from the Grand River, was constructed through the canalization of rivers north of the Niagara Escarpment, by locks across this relief barrier, and a man-made cut to the south. The canal then took advantage of the Welland and Niagara rivers to reach Lake Erie. Hardly a feature of this achievement was as anticipated and, in 1833, the route was changed by a cut direct to Lake Erie at Port Colborne. The Second Canal, opened in 1845, followed essentially the same route, but with stone locks and a new channel constructed slightly to the west of its predecessor. The Third Canal was wider and deeper. It offered fewer locks and, though retaining Port Dalhousie as its northern outlet on Lake Ontario, its alignment was now a cut east of St. Catharines and Thorold across the Ontario Plain. The Second Canal remained in use at the two ends for the smaller-sized vessels to serve St. Catharines and Thorold, and its water supply continued to power industry until hydroelectricity was obtained from the power projects on the Niagara River at Niagara Falls. Key words: Welland Canal, St. Lawrence–Great Lakes water system, William Hamilton Merritt, transportation, Grand River, Lake Erie, Lake Ontario, water power, industrial location, urban growth.