Waterbody Type:Mid-sized coarse substrate-dominated siliceous highland river (type 9) 
Small coarse substrate-dominated siliceous highland river (type 5)
Elevation:160 m.a.s.l. to 595 m.a.s.l.
Length:29.0 km
Discharge:Mean low water: 0.7 m3/s
Average Discharge: 3 m3/s
Mean high water: 24 m3/s
Basin:203 km2
Particularities:Upstream of the town of Sundern, part of the Röhr’s discharge and that of its two side arms Waldbach and Settmecke is transferred to the Sorpe Reservoir via a diversion system. Starting at Hachen, the Röhr’s discharge is affected by the reservoir and dam system.