Construction of a new 6.5km pipeline began in summer 2019 and is planned to finish by spring 2023. It will connect Bristol’s existing trunk sewer in Lawrence Weston to the Frome Valley relief sewer near Cribbs Causeway and will direct waste more efficiently around North Bristol to our water recycling centre in Avonmouth.
The majority of the sewer has been constructed by tunnelling underground using a tunnel boring machine, reducing the need to dig trenches. We have even tunnelled underneath the M5 motorway and Network Rail’s Henbury Loop freight railway.
We are working with contractors J. Murphy & Sons Ltd to construct the tunnel and lay the pipework.
The North Bristol relief sewer forms an essential part of our long-term sewerage strategy for the next 100 years.
Our tunnel boring machine has recently finished its journey. Watch the video below to see how the tunnel is built and click the drop-down options to find out relevant information for each area of North Bristol where activity is happening.
Construction of a temporary site compound and tunnel entrance in the hillside below Oasis Academy Bank Leaze began in August 2019. The tunnel boring machine (TBM) was scheduled to launch from this site in March 2020. However, the launch was postponed due to the Covid-19 pandemic. The TBM was eventually launched in June 2020 and has now completed its journey northwards to construct the 5.5km tunnelled section of the sewer. It was removed from the ground in February 2022.
Now that the tunnelling work has finished, the site’s 24-hour operations will stop. However, HGV movements and deliveries will remain restricted and will not be permitted between the hours of 7pm and 7am.
A smaller section of sewer to connect the main tunnel with the existing Bristol network has now been constructed behind Saltmarsh Drive, through the playing fields of St Bede’s Catholic College and behind Attwood Drive. Construction of this section and reinstatement of the area was completed in autumn 2020.
Customers may have noticed a decrease in vehicle movements through Lawrence Weston now that tunnelling has finished. However, we will still need to as we receive material deliveries and remove construction waste while the tunnel is fitted out with mechanical and electrical equipment. We will continue to do everything we can to minimise traffic disruption and are coordinating our vehicle movements with local schools.
Extensive work has been required in the Henbury area to connect the existing sewerage network to the new relief sewer.
In August 2020 we completed the construction of a 30-metre- deep shaft at our site compound in Crow Lane Open Space near Tormarton Crescent. The tunnel boring machine, which was launched from our main site in Lawrence Weston during the summer of 2020, successfully arrived at the deep shaft in April 2021. This provided the opportunity for maintenance to be carried out on the tunnel boring machine before it continued its journey towards Almondsbury.
In June 2021 the tunnel boring machine left the Henbury area and cleared the railway line that passes underneath Wyck Beck Road. The shaft compound in Crow Lane Open Space has been cleared of tunnelling equipment and our contractors have now returned to fit out the deep shaft with mechanical and electrical equipment. The shaft will remain capped with a steel cover to keep it secure and the area will continue to be patrolled by our security team. The temporary track will remain through the Open Space for the time being.
To make the connection between the existing network and the new sewer, we have constructed an additional pipe through Crow Lane Open Space and the playing field of Henbury Court Primary Academy. Most of this pipe was installed using a ‘no-dig’ pipe jack technique to avoid open trenching.
Watch our tunnel boring machine breaking through in Henbury...
Reinstatement of the community orchard off Henbury Road close to the ford is now complete, along with the reinstatement of Henbury Court Primary Academy’s playing fields.
Members of the public are still able to use Crow Lane Open Space during our work and we are continuing to provide safe crossing points along our temporary access track.
The new connecting sewer pipe and manhole have been successfully constructed in Catbrain and all temporary measures, such as the culvert crossing ramp at the bottom of Catbrain Hill, have been removed.
During 2021, the reinstatement work between Catbrain Hill and Medlar Close was unfortunately delayed while we consulted with the landowner. A reinstatement proposal has now been agreed and work to replant the hedgerow and construct an additional robust timber fence will start in Spring 2022.
Work in the former Filton Airfield to construct the 30-metre-deep shaft was completed in November 2020 and the tunnel boring machine arrived in the shaft in August 2021. Now that the machine has finished its journey, work will resume inside the shaft to install mechanical and electrical and flow control equipment. We aim to finish this by summer 2022.
Our tunnel boring machine successfully completed its journey and arrived at The Bristol Golf Club on 28 January 2022, where it was taken out of the ground inside a site compound that we’ve built on the golf course.
The site compound is located on the edge of the 15th fairway of the golf course, close to the 15th hole and the 17th tee.
We have finished the new connecting chamber that links the existing tunnel to the new relief sewer and will now carry out mechanical and electrical work before removing the site compound. We aim to have this completed by the end of summer 2022.
To access our site compound, the track that runs adjacent to the 15th fairway has been temporarily widened for our construction vehicles. A banksman will manage vehicle movements through this road to ensure members can still play safely.
Newt fencing has been erected around the site compound and will remain in-situ throughout the work. This is to ensure great crested newts and other reptiles can be safely collected and relocated to a safer location during our work.
With the help of our very own trained sniffer dog Freya, prior to arriving on-site the totals during the trapping period were 32 great crested newts, nine slow worms, three smooth newts, 11 toads and one frog.
Information on how to safely play golf between the 15th and 17th holes has been shared with members and flyers will also be available at the pro shop.