Noun
-
an event marking a unique or important historical change of course or one on which important developments depend
"the agreement was a watershed in the history of both nations"
- turning point -
the entire geographical area drained by a river and its tributaries
an area characterized by all runoff being conveyed to the same outlet
"flood control in the Missouri basin"
- river basin - drainage basin - catchment area - catchment basin - drainage area -
a ridge of land that separates two adjacent river systems
- water parting