Scotland Performs Update

National Outcome: We reduce the local and global environmental impact of our consumption and production

Scottish Water – Shieldhall Tunnel Project

Background

• Scottish Water is building a 3.1 mile-long waste water tunnel in the south of Glasgow as part of the biggest upgrade of the city’s waste water network in more than a century.
• The tunnel is being constructed from Craigton Industrial Estate, and runs under Bellahouston Park, Pollok Park, along Titwood Road to Queen’s Park where it ties into the existing sewer network.
• The tunnel route was carefully selected to minimise disruption.
• It is due to be operational in May/June 2018.

Budget

• £100m.
• This project forms part of Scottish Water’s £250m five-year investment programme in Greater Glasgow.

Achievements

• The tunnel, which is 4.7 metres in diameter, is big enough to fit a double decker bus inside and more than five times as long as the Clyde Tunnel.
• It will provide 90,000 cubic metres of extra storm water storage, the equivalent of 36 Olympic- sized swimming pools.
• The increased capacity will reduce the risk of flooding in parts of the Mount Florida, Toryglen and Giffnock areas.
• It will deliver water quality improvements to the River Clyde by reducing overflows from the sewer network.
• More than 90% of the excavated material has been recycled.

Key partners

• The team building the Shieldhall Tunnel for Scottish Water, known as the Glasgow Tunnel Partnership, is a commercial joint venture between Costain and VINCI Construction Grands Projets, called Construction Grans Projets Joint Venture ( CVJV). Costain and VINCI have been involved in some of the world’s major engineering projects, including the Channel Tunnel.

Delivery

• The tunnel is being constructed using a specially designed tunnel boring machine which at 180 metres long, is longer than 14 buses end-to-end and weighs about 1000 tonnes, more than the weight of two Boeing 747 jets.
• Following the installation of the last full circle of concrete rings that form the tunnel, work will now progress on connecting it to the existing waste water network in Queen’s Park before it becomes operational next year.

Delivery (continued)

• Since construction began:
  • More than 3,200 concrete rings of the tunnel (which are 1.5m-long) have been completed – each made up of six curved pre-cast concrete segments weighing 2.5 tonnes each which create a full circle when installed.
  • More than 500,000 tonnes of earth, stone, clay and other aggregates have been excavated.
  • More than 1.5 million hours of work have been completed on its construction.
  • More than 20 miles of pipes have been installed in the tunnel to service the tunnelling machine with air and water.

Contribution to National Outcomes

• Providing an effective waste water network which serves our growing communities is vital to Glasgow’s infrastructure and environment, now and for future generations.
• It contributes towards providing safe and sustainable ways of managing waste in our biggest city. It is a significant part of the overall investment in Greater Glasgow which is essential to economic prosperity regionally and nationally.
• Improving drainage and sewerage infrastructure below ground will help deal with the impact of climate change while also helping the city to grow, develop and flourish.

The project contributes towards other National Outcomes, such as:

• We live in well-designed, sustainable places where we are able to access the amenities and services we need.
• We value and enjoy our built and natural environment and protect it and enhance it for future generations.