geographic feature headwater ENVO ENVO:00000153 FTT:105 FTT:1221 FTT:1259 FTT:220 FTT:644 Geonames:H.STMH HEADWATER TGN:21181 The upper part of a river system, denoting the upper basin and source streams of a river. Wikipedia:Headwater drainage basin headstream headwaters source stream