First Welland Canal reason for the error is not known. On July 4, 1818, Merritt organized a meeting in St. Catharines. The outcome was a petition sent to Upper Canada Legislature to provide for construction of a canal between the Twelve Mile Creek and Welland River. Unlike Merritt's original water-canal plan, the petition included plans for allowing boats to cross the Niagara Escarpment. In 1823, Hiram Tibbetts, an engineer, was employed to make a formal survey for the route. He suggested to dig a channel below the surface level of Welland River between present-day Port Robinson and Allanburg, and then follow the Twelve
Welland Canal updated systems for Locks 1 through 7 will be completed in 2017. In the 1950s, with the building of the present St. Lawrence Seaway, a standard depth of was adopted. The long Welland By-Pass, built between 1967 and 1972, opened for the 1973 shipping season, providing a new and shorter alignment between Port Robinson and Port Colborne and by-passing downtown Welland. All three crossings of the new alignment—one an aqueduct for the Welland River—were built as tunnels. Around the same time, the Thorold Tunnel was built at Thorold and several bridges were removed. These projects were to be tied into