Winn Brook is a tributary of the of the River Exe.. The source of the Winn Brook is south of Little Ash Farm near Comer's Gate. From the source it flows in a generally easterly direction flowing below Winsford Hill. It is first joined by waters from Little Ash Combe and then Ash Combe before flowing through Great Ash Wood were it is joined by a further tributary stream. Continuing in an easterly direction it reaches Withycombe where waters from the Punchbowl join. From Withypool in flows through fields and Burrow Wood to reach the River Exe at Winsford.