Channel
"1. Deepest portion of the main course of a river.
2. Natural or artificial waterway with periodical or continuous water flow which may link two bodies of water." (United Nations Publicatons, 2013)
Sources
United Nations Publications. "Glossary of Shared Water Resources (English-Arabic): Technical, Socioeconomic and Legal Terminology." (2013). DOI:https://dx.doi.org/10.18356/70b462ce-en