The Rench is an eastern tributary of the Rhine in the Ortenau in Central Baden, Germany. It rises on the southern edge of the Northern Black Forest at Kniebis near Bad Griesbach im Schwarzwald. The source farthest from the mouth is that of the Schöngrundbächle which rises at a height of around 915 m above NN in the parish of Zuflucht. After flowi…The Rench is an eastern tributary of the Rhine in the Ortenau in Central Baden, Germany. It rises on the southern edge of the Northern Black Forest at Kniebis near Bad Griesbach im Schwarzwald. The source farthest from the mouth is that of the Schöngrundbächle which rises at a height of around 915 m above NN in the parish of Zuflucht. After flowing through its steep mountainside klinge it is joined by other streams to form, first, the Old, then the Wild Rench, which first becomes the Rench below Bad Griesbach. The Rench runs in a prominent southerly arc through the Central Black Forest and crosses the hilly region of Ortenau with its orchards and vineyards before breaking out into the Rhine Plain. After just under 57 km it, together with the Mühlbach, confluences with the Rhine at 314.7 km between Helmlingen and Lichtenau.