Sustainable supply to the central Waldviertel region

Austria is often envied for its abundance of water, but groundwater reserves and demand for drinking water vary greatly from region to region. By building a 60-kilometre-long transport pipeline, EVN Wasser GmbH is clearly demonstrating its commitment to ensuring a secure and sustainable water supply in the central Waldviertel.

Plenty of groundwater in Krems, too little in Zwettl
The new pipeline starts in the Grunddorf/Donaudorf well field near Krems, which has sufficient surplus groundwater, and ends in Zwettl. With an investment volume of around €50 million, this extensive infrastructure project is scheduled for completion in autumn 2025.

Five years for construction
The groundbreaking ceremony for the three-stage project took place in July 2020. The first two stages were completed in 2022 and 2024 respectively, and the third section of the pipeline is currently under construction. In addition to the supply line, three elevated tanks along the route are also necessary to ensure smooth operation. These serve as drinking water backup and also provide the technical conditions necessary for increasing pressure in the pipeline, since the difference in altitude between the well field in Grunddorf/Donaudorf and Zwettl is about 450 metres.

Challenging route
The subsoil poses a number of challenges along the 60 km length of the jobsite. "Depending on its hardness, we have to blast, cut or dig to lay the new pipes," explains EVN project manager Markus Eschelmüller. "We've had to overcome railway tracks, main roads, watercourses and gas pipelines," he continues. "We've used virtually every laying method available: horizontal and directional drilling, as well as open and closed watercourse crossings with boreholes."

The laying of pipes in strings up to a kilometre long proved to be quick and cost-effective, allowing the stage to be completed ahead of schedule.Markus Eschelmüller, Project Manager EVN Wasser

Tried-and-tested logistics with Alpe Pipe Systems
For the second section, 10.5 km of HFI-welded steel pipes were used, which were supplied punctually and reliably over a period of about a year by the Tyrolean Alpe Pipe Systems. The steel pipes produced by Mannesmann Line Pipe in Hamm were coated with PE and lined with cement mortar to provide maximum corrosion protection.
    Thorsten Schmidt, who has overseen the Mannesmann Line Pipe contract from the outset, points out: "Working with our long-standing sales partner Alpe Pipe Systems, we were able to bring our expertise to bear in combination with precision logistics." In addition, further optimisations were made in the course of the project with regard to pipe lengths and angles in the sockets.

Swift and cost-effective laying
Supplied in lengths of 8 to 15.5 metres, the pipes fitted with tried-and-tested slip welding joints enabled rapid installation. The pipes were welded together in strings up to a kilometre long, field-coated and lowered into the prepared trenches in a single operation. This method proved to be quick and cost-effective, allowing the stage to be completed ahead of schedule.

Contract also awarded for third stage
Thanks to the smooth logistics services and excellent experience with pipe-laying, Mannesmann Line Pipe was also awarded the contract for the third section. This is where another 10 km of HFI-welded DN500 steel pipes with a wall thickness of 6.3 mm and the same coating and lining will be used as for the second section. The pipes will again be efficiently transported by truck by Alpe Pipe Systems from Hamm to the jobsite in the Waldviertel region on a just-in-time basis.

Secure supply for around 120,000 residents
Traditionally short of groundwater, the central Waldviertel region in the districts of Zwettl, Gmünd and Waidhofen an der Thaya will enjoy a secure water supply when the pipeline comes into operation in autumn 2025. A population of around 120,000 will then have a reliable supply of water in the long term.