Tram expansion and sewer construction commence
As part of the double-track expansion of tram line 1 in Hilmteichstraße, a rail replacement service will be in operation between Hilmteich and Mariatrost from the beginning of November. The reason for this is the implementation of another important project: the storage canal in Mariatrost is being expanded and extended.
‘Graz is expanding’. Under this motto, the public transport network in Graz (Neutor line, track work in the west of Graz) will be further expanded in 2025 and, at the same time, the water, energy and telecommunications infrastructure will also be improved.
On 3 November 2025, another transport project will begin with the double-track expansion of line 1 in Hilmteichstraße. Deputy Mayor Judith Schwentner:
‘With the double-track expansion of Line 1, we are creating faster and more reliable connections for thousands of passengers. At the same time, new cycle paths and footpaths as well as more greenery will ensure greater safety and quality of life along Hilmteichstraße. The people of Mariatrost will benefit twice over: from better mobility and from clean water thanks to the new storage canal.’
On behalf of the Holding Graz board, CEO Wolfgang Malik, Gert Heigl and Mark Perz emphasise that tram line 1 currently runs at an average interval of 10 minutes. One of the reasons for this is that the trams currently only have one track available on a 900-metre stretch of Hilmteichstraße. With the construction of the second track between Auersperggasse and the Mariagrün stop and the completion of the extension to Mariatrost, it will be possible to run trams every 6 minutes along the entire route of line 1 in future. In the best-case scenario, trams will thus be able to transport 1,500 passengers per direction per hour to their destination, according to the holding company’s management board.
Start of construction of the storage canal necessitates rail replacement service
The start of the double-track expansion of the line will take place on 3 November 2025 with the construction of the Mariatrost storage canal. This major project, which is of enormous ecological importance for Mariatrost and is being implemented by Holding Graz as part of the ‘Graz baut aus’ (Graz is expanding) programme in Hilmteichstraße, will result in rail and bus replacement services between Hilmteich and Mariatrost (see appendix).
The construction of the canal is necessary because there are still combined sewers in the Mariatrost Valley, which carry away both sewage and rainwater. The problem is that during heavy rainfall, large quantities of rainwater flow in that cannot be absorbed by the existing facilities, resulting in the planned overflow of the combined sewers into the Mariatrosterbach stream.
As this outdated system has a negative impact on the entire ecosystem, not only is the new storage canal with a length of around 630 metres being built in Hilmteichstraße, but the necessary connections to the existing sewer network in the surrounding area are also being constructed. In addition, necessary conversion work or new construction of throttle and overflow structures is being carried out. In future, mixed water will be collected in this storage facility and forwarded to the sewage treatment plant. Manfred Eber, City Councillor for Finance and Investment: “The new storage canal ensures clean water and provides better protection during heavy rainfall. This benefits both the residents of Graz and the natural environment. With “Graz expands”, we are continuing to invest in important infrastructure. The construction of the storage canal will take about a year and cost around 9.3 million euros. This investment will have a direct impact on the quality of life in Graz.”
Incidentally, the canal, which will be located 5 to 10 metres below the railway tracks, will be built using a drilling technique known as ‘microtunnelling’. This is a trenchless technique for laying pipes and cables underground. It is an environmentally friendly, selective method that causes minimal disruption to the surface.
