Schwechat, River, Lower Austria, southwestern tributary of the River Danube, 62 km long, of average to poor water quality, average discharge rate 7.9 m3/sec. (at Schwechat). The River Schwechat originates from the confluence of several small rivers near Schoepfl Mountain (alt. 893 m) in the Vienna Woods, flows through the Helenental Valley, Baden (alt. 232 m), Laxenburg (alt. 177 m), the northwestern parts of the Vienna Basin and ends east of Schwechat (alt. 163 m). Tributaries: Moedling, Liesing and Mitterbach.