Traisen, River: Lower Austria, southern tributary of the Danube; the River Traisen rises to the west of St. Aegyd am Neuwalde (two headstreams, alt. 588 m): the Unrecht-Traisen stream flows to the north through St. Aegyd and Hohenberg (alt. 488 m), the Tuernitzer Traisen stream flows to the northwest and turns to the northeast at Tuernitz (alt. 466 m). The River Traisen originates at the confluence of the two streams at Freiland: it flows through the towns of Lilienfeld (alt. 383 m), Traisen (alt. 356 m), Wilhelmsburg (alt. 321 m), St. Poelten (alt. 271 m), Herzogenburg (alt. 229 m) and Traismauer (alt. 197 m). When Grafenwoerth power station was built, the confluence of the rivers Traisen and Danube was moved to the east. From Spratzern to Traismauer there are two artificial factory canals on both sides of the Traisen, which are maintained by the Traisen-Wasserverband (Traisen Water Association) and the Werksbach cooperatives. The Traisen Sewerage Association, established in 1960, built an outfall sewer from Lilienfeld to Traismauer (46 km long, with central sewage plant) between 1965 and 1992; the most important tributary is the River Goelsen.