Powtrail Water, a head-stream of the river Clyde in Crawford parish, Lanarkshire. It rises on the northern side of Scawd Law (2166 feet) at an altitude of 1900 feet, close to the Dumfriesshire boundary; runs 7 miles north-north-eastward to a confluence (970 feet) with Daer Water, at a point 2¾ miles S of Elvanfoot station; and brings down the Roman or `Wellpath' road from Nithsdale to Clydesdale.—Ord. Sur., sh. 15, 1864.

(F.H. Groome, Ordnance Gazetteer of Scotland (1882-4); © 2004 Gazetteer for Scotland)