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How did the United States bypass the Long Sault Rapids during the St. Lawrence Seaway project?

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Map showing the St. Lawrence hydrographic system and the five main sectors of the St. Lawrence Seaway project, stretching from Lake Ontario near Kingston through various locks, canals, and dams along the Canada-United States border to Montreal. The map highlights key locations such as the Thousand Islands, International Rapids, Lake St. Francis, Soulanges, and Lachine sections, with detailed labeling of major locks, canals, and power dams. Cross sections of the lock and canal system are depicted — St. Lawrence Seaway The St. Lawrence hydrographic system, with the five main sectors of the St. Lawrence Seaway project.

To bypass the Long Sault Rapids during the St. Lawrence Seaway project, the United States constructed a canal and two locks to navigate around the Barnhart Island–Cornwall generating dam located at the foot of the rapids.12

Specifically, the U.S. portion of the project involved the following:

Canal Construction: A 16-km (10-mile) canal was built to bypass the rapids.3
Lock System: Two locks were constructed to manage the change in water elevation: the Bertrand H. Snell Lock and the Dwight D. Eisenhower Lock.2

These works were part of a broader agreement between the United States and Canada to create a deep-draft navigation channel, which also included the development of hydroelectric power in the International Rapids section of the St. Lawrence River.312