They are useful because they are the source of which many boats travel on. It is also very traditional in Dutch culture and many other cultures too.
Mostly the Erie Canal today is used for recreation and fishing. However some farmers ship grain to be made into ethanol.
Small boats and pleasure craft uses the Erie Canal today. It is also a cycling trail and used for fishing. But there still is some commercial traffic.
The Rideau Canal provides a route from Ontario to Montreal. It isn't used much today, but it won quite a lot of awards.
The Panama Canal Authority .
Yes the Erie Canal is still in business today. Much of it is now recreation but there is still commercial traffic such as barges of corn from Canada to be turned into ethanol.https://www.npr.org/2013/06/25/195426326/commercial-shipping-revived-along-erie-canal
Yes, the Erie Canal is still accessable today.
The Panama Canal Today - 1913 was released on: USA: 30 April 1913
It is used for transporting oil to various different regions such as China, The Americas, and Europe
France
BRB canal
The primary purpose of the Erie Canal when it was built was to bring wheat from Ohio to New York. It brought the price of shipping down by 90%. The Erie Canal's utility as a commercial waterway was later overtaken first by railroads and later by Interstate highways. Today it is primarily used by pleasure craft.
Yes the Panama Canal is what Therodore Roosevlt aspired it to be