The construction phase of Scotland’s biggest waste water tunnel, which will help tackle flooding and improve river water quality in the Glasgow area, has been completed.

A giant state-of-the-art tunnel boring machine (TBM) has spent 15 months creating the 3.1 mile-long tunnel or sewer beneath the south of the city and last night “broke through” in Queen’s Park.

The construction of the tunnel, which runs from Craigton to Queen’s Park via Bellahouston and Pollok parks, is a major milestone for one of the most important pieces of waste water management infrastructure installed in Glasgow since Victorian times.

With this key phase of the £100m project now complete, further construction and ancillary work will be carried out including work to connect the tunnel to the existing waste water network before the tunnel becomes operational next summer.

The 1000-tonne TBM, which began its mammoth task beneath Glasgow’s south-side in July 2016, has now completed the installation of the last of more than 3200 concrete rings that form the tunnel.

Welcoming the landmark moment in the project, Douglas Millican, Scottish Water’s Chief Executive, said: 

“We are delighted to have completed the construction phase of the Shieldhall Tunnel, which is the flagship project in Scottish Water’s investment in the waste water infrastructure in the Greater Glasgow area - the biggest in well over a century.

“The tunnel will improve water quality in the River Clyde and reduce the risk of flooding in a number of communities. As the Greater Glasgow area continues to develop, we are modernising our waste water infrastructure to support the needs of both existing and future customers.

“The completion of the Shieldhall Tunnel, which will increase capacity and alleviate pressure on the existing network by providing additional storm water storage, is a key part of that network modernisation."

Construction of the tunnel marks the completion of the most challenging part of the project. Scottish Water will now move to linking the tunnel to the existing Glasgow waste water network and bringing the whole new system into operation next year.

Many hundreds of people have worked as part of the Costain VINCI Construction Grans Projets Joint Venture (CVJV), which was set up to deliver the tunnel. The project has required a wide range of specialist skills, knowledge and expertise - the workforce has included local contractors and those with international experience and backgrounds.

Neil Grosset, Project Director for CVJV on the Shieldhall Tunnel, said:

“All at Costain and VINCI Construction Grands Projets are delighted to have completed construction of the Shieldhall Tunnel for Scottish Water and the people of Glasgow.

“This is one of the most challenging projects many of us have worked on and the completion of the tunnel construction is testament to the skills, knowledge and determination of our team who have safely delivered a high quality piece of infrastructure that will have a huge positive impact for the city now and in the future.”