Significant subsidence in the Duisburg area had led since 1900 to the fact that dammed the water of the river Emscher in the western Ruhr area. 1910 therefore moved the Emschergenossenschaft the mouth of the course further north, in the course of today's little Emscher. 1949, the course was then again moved further north, so that the Emscher opens today at Dinslaken into the Rhine. The original estuary to 1910, the Old Emscher.
The oxbow lake is in the lower course still an open, channeled, is laid out with concrete slabs wastewater stream for domestic and industrial wastewater. It rises a main collector in Oberhausen -Busch Hausen and flows in a northwesterly direction through Marxloh until after Walsum to the north of South Haven in the Rhine to lead. From the wastewater treatment plant in Duisburg-Walsum purified water only flows into the partially built already back riverbed. Even below the wastewater treatment plant of the river and its inlets has been improved, ecologically. Along the river bed runs the Green Path, a hiking and biking trail along the former route of the Emscher Valley Railway.
The little girl is cut from the Emscher river system in the Emscher, obtained from the Röttgersbach, the main collector and the upper Marxloh Holtener mill creek inlets and discharges at kilometer 791.3 as a right tributary of the Rhine.