Confluence, in geography, describes the meeting of two or more bodies of water. It usually refers to the point where a tributary joins a more major river, called the mainstem, when that major river's also the highest order stream in the drainage basin. The term's also used to describe the meeting of tidal or other non-riverine bodies of water, such as two canals or a canal and a lake. A one-mile (1.6 km) portion of the Industrial Canal in New Orleans accommodates the Gulf Intracoastal Waterway… (More on Confluence)