What is Watershed?
Watershed is (noun) 1. the high ground separating different rivers and the streams that run into them The ridge of hills marks the watershed between the Rhine and Rhone. 2. a point where an important permanent change takes place Failing the exams for the Civil Service was a watershed in his career. the nine o’clock watershed the time, 9.00 p.m, when adult programmes can start on TV
source: Easier English, Student Dictionary Upper Intermediate Level