Ysper#

River Ysper (also: Isper), Lower Austria, northern tributary of the River Danube in the southern Waldviertel area, flows into the River Danube to the west of Weins (alt. 240 m); mean rate of flow 2,4 m3/sec (Isperdorf). It arises from the confluence of the Rivers Grosse Ysper and Kleine Ysper, which issue in the southern Weinsberger Wald Plateau. Oedteich lake and Ysperklamm gorge are situated on the upper reaches of the River Ysper, the River Kleine Ysper partially forms the boundary between Lower and Upper Austria. Municipalities include: Dorfstetten (River Kleine Ysper, alt. 740 m), Niederndorf, Mitterndorf (at the confluence of the Rivers Grosse and Kleine Ysper, alt. 481 m), Ysper (alt. 504 m) and Altenmarkt (River Grosse Ysper, alt. 498 m).