MSP sees progress of low-carbon 'super sewer' investment for Perth

“Scottish Water has set a challenging target to go beyond net zero emissions across all of our work by 2040, including the delivery of our significant investment programme. Finding lower carbon ways to build new infrastructure is a crucial part of that journey.”

Neil McCulloch
Senior Project Manager, Scottish Water

Local MSP John Swinney has visited the site of the major drainage upgrade being delivered by Scottish Water in central Perth to support the city’s growth and reduce the risk of sewer flooding.

While on site in Tay Street and Shore Road, Mr Swinney was shown the innovative 2.2 metre diameter steel-reinforced composite pipe which is being used to upgrade a critical section of the city’s sewer network.

Modern sewers of this scale would ordinarily be built using concrete pipe to achieve the required strength, but manufacturing and transporting these across long distances generates significant carbon emissions. The composite steel pipe being used has a lower carbon cost and is much lighter, while having higher strength than could be achieved using plastic pipe at this scale.

Installation of the new ‘super sewer’ has been progressing well in both Shore Road and Tay Street since June.  Shoring piles measuring 6.5 metres are first vibrated into place to enable the safe creation of a deep excavation, allowing the pipe bed to be laid and the pipes to be positioned around 4 metres below ground level. As each section is backfilled, the shoring piles are relocated to enable the next one.

The super sewer is the first element of a major programme of investment in the Fair City’s water and sewerage infrastructure which is set to be delivered over the coming years. The new pipe will play a key role in supporting the city’s continuing growth, while also reducing the risk of sewer flooding affecting low-lying areas between Muirton and the city centre.

Scottish Water’s Senior Project Manager Neil McCulloch said: “The work we are delivering is vital for the future of Perth, responding both to the city’s growth and the impacts of climate change that we are already starting to see.

“While we are adapting our infrastructure to a changing climate, we also need to play our full part in addressing its causes. Scottish Water has set a challenging target to go beyond net zero emissions across all of our work by 2040, including the delivery of our significant investment programme. Finding lower carbon ways to build new infrastructure is a crucial part of that journey.”

After touring the site, local MSP John Swinney said: “This is a very significant infrastructure project and a huge capital investment that Scottish Water is delivering. It brings with it a lot of disruption, but the work is so important to provide for the expansion of the city, to provide for the new housing that is needed and crucially to alleviate some of the pressures from climate change such as flooding.

“All of us can see that the weather around us is changing. We’ve got much heavier, sharper inundations of rainfall; and the traditional sewage infrastructure of Scotland isn’t designed for that. The storage capacity in the super sewer will help to future-proof the city for climate change as well as its continuing development.”

While work continues, road closures remain in place on the section of Tay Street between Canal Street and Marshall Place; and on Shore Road alongside the South Inch – although access to the South Inch public car park remains open.

Following work with Perth & Kinross Council to investigate options to improve the flow of traffic at the junction of Edinburgh Road and Friarton Road, manually-controlled traffic lights will now operate at this location from Monday to Friday between 3:30pm and 5:30pm.  The junction of Cromlix Road and Friarton Road will also be closed during these times, with local access only being possible from Drummond Crescent.

Neil McCulloch added: “We recognise that engineering work of this scale is unavoidably disruptive, particularly for the road network, but we’re committed to seeking the best solutions we can find.

“Our team will continue to do all they can to minimise delays at peak times for users of Edinburgh Road and Friarton Road, while ensuring that everyone can complete their journey safely. We would ask road users to bear with us and allow some extra time where possible. It will not be possible to get through via Cromlix Road and we would ask everyone to follow the signs in place.”