Pumping Station

Photo © Christa Lachenmaier
Photo © Christa Lachenmaier
Photo © Christa Lachenmaier
Photo © Christa Lachenmaier
Photo © Christa Lachenmaier
Photo © Christa Lachenmaier
Photo © Christa Lachenmaier
St. Leonardus Straße, 50735 Cologne
Stadtentwässerungsbetriebe Köln
2005, 1st prize
9.500 sqm
Johannes Groote, Till Hoevel, Rüdiger Hundsdörfer, Norbert Philippen, Miriam Pfeiffer, Bernhard Schumann
Heinze Architekten Award 2011, Shortlist | Kölner Architekturpreis 2010, recognition

Moss can filter water which, when fresh and clean, is a most precious good. The infrastructure required to produce, purify, and distribute water in large cities is, however, mostly hidden from public view. It therefore seemed obvious that the new pumping station in Cologne, located by the banks of the Rhine River, would make this process visible by means of a wall of moss facing the street. It serves to illustrate the basic purification process of water even though the new building houses elaborate filtering technology that is rather different from that of gentle moss-based filtering. The pumping station’s main task is to treat rainwater before it is released into the Rhine River. As such, the building reflects this internal process in tangible terms. The storm water pumping station is one of seven new pumping stations that line the Rhine like a “string” of pearls.

A discerning plant, moss favors permanently moist environments and eschews direct sunlight. Along the Rhine River, it mostly thrives in areas where water levels alternately rise and fall. Utilizing Bonn University’s professional expertise on moss, the study of which is collectively known as bryology, it became possible to plant small patches of moss on a moistened basalt wall. The horizontal gaps along the nine meter high and forty meter long wall allow the moss to strike roots, lending the facade a charming jazzy note. It is at these gaps, sprinkled with rain water, that the “green coat” grows first. Industrial expanded metal was used on those facades that face away from the river, while Mendig basalt was used on the side facing it. The facade design itself reflects both urban development sides of the site: the surroundings of the plot at St.-Leonardus-Strasse are characterized on the one side by rather nondescript industrial and commercial buildings, and on the other by the enticing meadow landscape of the Rhine River banks. Here, in this conventional-looking commercial area, a handsome facade has been built. Basalt was chosen since the walls along the river promenade have traditionally been constructed out of this dark stone. The expanded metal used on the rear facility has a facade shaped like a light envelope, encasing the different types of equipment inside, and dispensing with a weather shield.

The design brings together all the technical elements into one built volume, arranging them in a single building envelope of which the larger part lies underground. The building’s geometry is rather complex: the meandering basalt wall, for example, is doubly curved, making space for a small public square. A rainwater sedimentation basin lies behind the building. Apart from housing technical equipment such as generators and transformers, the street-facing building provides access to the five basement levels which accommodate the large pumps and “slides” that protect the city from floods. The pumping station in Cologne appropriately reflects the process of ecological rainwater purification. Moss plants are able to indicate organic and chemical pollution, acidification, and heavy-metal contamination in water. The building is a unique and architecturally fitting symbol for the quality of Cologne’s water, reflecting the Rhine region in its aesthetics and site-specific planning.

Cologne pumping station was part of the german entry to the 9th International Architecture Biennial São Paulo 2011.

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