Why were locks necessary on the Erie Canal?

Locks were necessary on the Erie Canal to allow boats to navigate through more than 150 meters (500 feet) of elevation change along the route. Because the canal traversed natural terrain with varying heights, these locks functioned as enclosures that could be filled or emptied to raise or lower vessels to match the water level of the next section of the canal.12

Engineers utilized 83 stone locks to overcome these natural obstacles, including significant barriers like the Niagara Escarpment, where a series of staircase-like locks were constructed to lift boats over the rock ridge. By managing these elevation differences, the locks enabled continuous water transport between the Great Lakes and the Hudson River, facilitating a vital commercial link.1