Here, a vital artery keeps Cologne’s surroundings alive. It is the Südlicher Randkanal. Imagine a network built to manage water. It protects the city and its neighbors.
The Südlicher Randkanal is part of a larger system. This system includes the Kölner Randkanal. Construction happened between 1956 and 1959. The aim was to drain areas west and northwest of Cologne. It also served the Rhein-Erft-Kreis.
The need arose from brown coal mining. Groundwater had to be diverted from these mining areas. The RWE Power AG played a crucial role in planning and building the canal. The former rural district of Cologne was also involved.
The Südlicher Randkanal extends from Köln-Lövenich. It reaches to the pumping station in Hürth-Hermülheim. This extension completed a ring around Cologne for drainage purposes. This ring is called Vorfluter Süd.
Several municipalities contribute to the Kölner Randkanal. These include Dormagen, Pulheim, Frechen, and parts of Cologne. Wastewater treatment plants and heavy rainfall also feed into the canal.
The Südlicher Randkanal flows north of Köln-Lövenich. It joins the Kölner Randkanal. This connection carries water from Hürth and Frechen. Water from the Köln-Weiden treatment plant also joins here. The Zweckverband Südlicher Randkanal is responsible for the Südlicher Randkanal.
The canal has a trapezoidal shape. The upper reaches feature cast-in-place concrete. The lower reaches use bituminous jointed paving on asphalt concrete. Grass usually covers the embankment crown. Hedges separate the water from the surrounding landscape.
The Kölner Randkanal stretches almost 20 kilometers. About 17.5 kilometers are open canal. Around 2.2 kilometers run underground. This underground section is the Worringen tunnel. The entire catchment area covers approximately 184 square kilometers.
The Pulheim retention basin offers the greatest retention. It is located at Randkanal-km 8.600. This basin can hold about 140,000 cubic meters.
Originally, natural streams weren’t enough. They could not drain the areas west of Cologne properly. The Südlicher Randkanal and the Kölner Randkanal became essential. They acted as artificial receiving streams leading to the Rhine.
Later, even these canals proved insufficient. New residential and commercial areas needed more drainage. So, Cologne, Hürth, and Frechen planned another artificial receiving stream. This stream would be built underground. This is the Vorfluter Süd.
The Vorfluter Süd is over 10 kilometers long. It was divided into sections. Its construction used pipe jacking methods. This project aimed to improve wastewater disposal. The cities of Cologne, Hürth, and Frechen commissioned it.
The Südlicher Randkanal stands as a testament to engineering. It highlights the importance of water management in urban development. Its creation has shaped the region. It protects against flooding and enables growth.