Flowing through Bonn and Alfter, what stories does the Hardtbach whisper? This stream, a left tributary of the Rhine, stretches 14.9 km. The Hardtbach goes by different names as it meanders through the landscape.
Let’s follow its course. The Hardtbach begins southwest of Volmershoven. Its source lies at 159 meters above sea level. From there, it flows northeast. It passes Volmershoven and Witterschlick. In Witterschlick, the stream flows through the Deutsche Steinzeug Cremer & Breuer works. Here the Hardtbach is channeled.
The Hardtbach continues through Nettekoven and Oedekoven. It reaches Lessenich/Meßdorf. Here at Bonn’s city limits, the Hardtbach becomes “Der Alte Bach.” The channeled Heilsbach joins it from the right. A few kilometers further, the Hardtbach arrives in Dransdorf. Now, it is called “Dransdorfer Bach.” In Dransdorf, the channeled Endenicher Bach joins from the right.
After passing under the A565 highway, another name change occurs. It is now called “Rheindorfer Bach” or “Mondorfer Bach” until it reaches the Rhine. The Hardtbach passes through Bonn-Castell. Finally, it flows into the Rhine at Graurheindorf. Its mouth is 50 meters above sea level. Over its course, the Hardtbach descends 109 meters. This results in an average gradient of 7.3 ‰.
The Hardtbach’s drainage basin covers 71.189 square kilometers. This area drains into the North Sea via the Rhine. The Engelbach drainage basin borders it to the east. The Godesberger Bach, another Rhine tributary, borders it to the southeast. To the southwest lies the Swist. It drains into the Rhine via the Erft. The Buschbach borders it to the west. It flows into the Swist. The Alfterer Bornheimer Bach borders it to the northwest. That flows into the Rhine.
The Endenicher Bach is the largest tributary of the Hardtbach. The Hünnesbach joins at kilometer 14.2 from the right. The Tonbach joins at kilometer 13.4 from the left. The Hitelbach joins at kilometer 12.0 from the right. The Katzenlochbach joins at kilometer 9.9 from the left. The Markeskaulenbach joins at kilometer 7.0 from the left. The Heilsbach joins at kilometer 4.3 from the right. Finally, the Endenicher Bach joins at kilometer 2.0 from the right.
The Hardtbach has many names. It reflects its journey through different areas. Each name marks a stage in its course. The Hardtbach flows into the Rhine. It contributes to the larger river system. From source to mouth, the Hardtbach shapes the landscape around Bonn. Its tributaries and drainage basin connect different areas.