Vienna's subway expansion hits milestone as giant drainage pipeline comes down

A massive drainage pipeline, installed in 2022 for Vienna's U2 and U5 subway expansion, is now being dismantled. The kilometre-long system, which diverted groundwater from the construction site, has been a prominent feature near City Hall and the Votivkirche for four years. Its removal signals a key step forward in the city's subway upgrade project.

The pipeline was put in place to lower groundwater levels during the construction of the new U2 and U5 lines. Over 100 wells were drilled around the site, extracting water from depths of up to 20 metres. This water was then channeled through the pipeline, which stretched roughly one kilometre and reached heights of seven metres in places, before emptying into the Danube Canal.

The construction work tied to the U-Bahn100 project took place in two phases. The first ran from 11 PM on Friday, March 20, 2026, until Sunday, March 22, 2026. The second phase followed immediately, lasting from Monday, March 23, to Sunday, March 29, 2026. Now, dismantling is underway, primarily at night to reduce traffic disruptions. The process is expected to finish by mid-April.

The pipeline had become a familiar sight in central Vienna, winding from City Hall along Reichsratsstraße and Maria-Theresien-Straße. Its removal marks the end of a temporary but essential measure that allowed the subway expansion to proceed without flooding risks.

With the pipeline now being taken down, the project moves closer to completing the new subway lines. The work has progressed in carefully planned stages to limit disruption to the city. Once finished, the expansion will improve Vienna's public transport network for years to come.