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Cen­tral reser­voir sewer

At the beginning of October 2017, the starting signal was given in Graz for one of the most important infrastructure projects of the last decades – the construction of the central reservoir sewer (ZSK). This sustainable project will ensure after its completion in 2022 that the Mur becomes even cleaner.

Zentraler Speicherkanal
© achtzigzehn

In Graz we have a so-called mixed-water sewer system – rainwater and dirty water run into the sewer at the same time and are mixed there with the waste water from Graz households and commercial enterprises. This is not generally a problem – as the waste water flows into the sewer system of the city of Graz and is cleaned there.

But: On around 50 days of the year, it rains so much in Graz that the sewer can no longer take up all the waste water and this therefore flows into the Mur. The consequence is a heavy burden on the water quality in the Mur – 660,000 kilogrammes of pollutants are currently still washed into the Mur untreated. Specifically: If the amount of pollutants that land in the Mur in this way every year is extrapolated, it corresponds to the annual waste water volume of a city with 28,000 inhabitants!

Dipl.-Ing. Dr. Kajetan Beutle, Head of the Graz Water Management division says on this: “The central reservoir sewer is one of the largest projects of the city of Graz in the field of environmental protection. We can be proud of that!”

As soon as the ZSK is in operation, the number of days on which pollutants are washed into the Mur will be reduced by at least 80%. This will mean that the pollutants that are washed into the Mur will be reduced by at least 50%. And that in turn will enhance the quality of life for people and animals.

Info on the trial operation of the Central Storage Channel from September 2021 can be found here!

The most important figures on the reservoir sewer
Construction costsEUR 81.4 million
Reservoir volume94,000 m3
Investments in conservationapprox. €1 million

Further information on this can also be found on the website of the central reservoir sewer.