Why were locks built on the Erie Canal?

Answer 1

Locks on canals exist because you need level water to be able to boat, sail or barge from one point to another. Unlike a road, a river or a canal cannot have a hill. Hills on water are called rapids or even worse waterfalls. The Erie Canal was and still is a man made river and it was made to facilitate boat and barge traffic between Lake Erie and the Hudson River. To build the canal, labors dug a hole in the ground that was about 4 feet deep, 20 feet wide and 365 miles long! The topography between these 2 spots goes from 0 feet above sea level to 420 feet above sea level by Rome NY, then drops to 363 ft around Rochester and then up to 565 ft by Lake Erie.

So imagine what would happen if they started to fill the canal with water in Rome NY? All the water would flow out to either Albany or Rochester, until there was no more water in the canal, making it impossible for ships or barges to use the canal. And this is because water seeks its own level or said another way, water always flows down hill. And it's this property of water that forces man made rivers to have locks. So what a lock does is create steps in the canal to step down to the level below or if traveling in the opposite direction step up to the level above. So the locks were built to allow boat and barges to sail up hill and down hill on a flat body of water!