A visit to the sewers below Riedmatt

“And what is that mountain over there called?” many a guest at a friend’s flat in the Riedmatt complex will have asked as they look towards the Rigi. “And what is that building down there by the school (main photograph)?” though this question may not have been so easy to answer. It is in fact the entrance to an extensive underground sewer system built with no lack of engineering skill.

The sewer collects the effluent not only from the municipalities of Baar and Zug, but also from Menzingen, Unterägeri and Oberägeri, all 800 litres of it per second, and this on a day when it is not raining. “It can get a bit nauseous after heavy rain,” said David Wigger, who enjoys the grand title of head of building projects of the Water Protection Agency of Lakes Zug, Aegeri and Küssnacht (GVRZ). “You get drowned rats floating on the surface, all bloated to the size of footballs,” he said, as his colleague, Edy Zihler, commented on the discarded croissants and floor-cloths floating on the surface, too. “It is amazing what people put down the loo.”

Indeed, what for most people has disappeared from view for ever, is very much visible down here. Inspectors made use of this opportunity to go check what state it was all in while it was temporarily closed off, not least for repairs with special mortar to be able to be made to parts showing decay. Regular readers will know a 500-metre-long section of the drainage systemin the city is currently being renovated at a cost of CHF 5.5 million.

Bernd Kobler, the managing director of the GVRZ, commented on the great foresight engineers had when they built this system in 1977, when there were far fewer people living in the afore-mentioned municipalities and fewer office blocks, too, an opinion shared by engineer Klemens Bannwarth, who is fascinated by such systems, and who commented on the high quality of it. Out of interest, it was mentioned how water consumption per head is actually falling and how, these days, rain water and effluent are increasingly being kept separate.

As can be seen in the second photograph, the system is high enough for a workman to be able to stand up in, even if he is wearing a helmet. Indeed, it is possible to stand up in a whole 12-kilometre section of the 80-kilometre pipe around Lake Zug.

Of course, it is all very much a drab, stuffy and monotonous environment to work in, the stench just about bearable for those who have to do so. Looking at one section which had already been renewed, Vigger commented on how clean it was. “You could even eat your dinner down here, if you wanted to,” he said.