When was the Cape Cod Canal built? The Canal opened July 29th, 1914. It was 100 feet in width and had a max depth of 25 feet. In 1940 the U.S Army Corps of Engineers completed a reconstruction project to improve the canal. Today the canal is 480 ft wide and 35 ft deep. Who built the canal? August Belmont, Jr. How long is the canal? The canal is 7 miles long and connects Buzzards Bay to Cape Cod Bay. How many bridges does the canal have? There are 3 bridges. The Cape Cod Canal Railroad Bridge (Buzzards Bay Railroad Bridge), Bourne Bridge and the Sagamore Bridge. All the bridge were opened in 1935.