We've completed the second of three Elan Valley Aqueduct bypass tunnels

We're happy to announce that we've completed the second of three huge multi-million pound bypass tunnels being built to reinforce water supplies for Birmingham, and the local people all came out to watch – even in the pouring rain.

The Elan Valley Aqueduct (EVA) has been bringing water to the homes and businesses of Birmingham and the surrounding area for over 100 years.  However, after so many years of service, the need for regular maintenance and refurbishment is becoming ever more frequent and so the time has come to provide extra support for the EVA to make sure that it can continue to provide service for another 100 years. 

Bring on the Birmingham Resilience Project – Severn Trent’s flagship £300M programme.

Paul Dennison, programme manager, explains: “At the moment, the EVA is the sole source of supply into Birmingham, and storage at our treatment works at Frankley means we can only turn it off for a few days at a time for maintenance.  To allow us to turn it off for longer periods, an alternative water supply for the city is being built.  Work began earlier this year on a new pipeline from Lickhill, near Stourport-on-Severn, 25km into the existing water treatment works in Birmingham.

“However, our checks on the existing aqueduct show that in three places, there is work that we'd rather do before the new pipeline is completed. As we can’t shut down the aqueduct, we've had to come up with alternative solutions.

”Three new tunnels are being built, then connected to the existing EVA at either end, to bypass sections of the aqueduct.  These will be at Bleddfa, Nantmel and Knighton.  Each of the multi-million pound projects is huge in its own right, and the machine used to cut the new tunnels is over 3 metres in diameter, so as you can imagine it's quite a job!  

Paul continued: “We’ve been working with our contract partner, the BNM Alliance, and we’re happy to say that another tunnel is now finished.  The tunnelling machine broke out successfully – right on target, completing the second tunnel, in front of huge numbers of local residents and dignitaries.

“The last few weeks have been a busy time for us as we’ve finished the tunnelling, but we now need to do the difficult bit, which is to transfer the flows from the 100 year old aqueduct at Nantmel into the newly constructed tunnel. The work will be part of a scheduled shut-down of the EVA, when flow through the aqueduct is suspended for five days to allow inspection and maintenance.

“This is a tricky job, and has to be done in a very short space of time – just five days.  We then need to put the site back to how it was before we arrived and we expect that to be around June 2018. Once we’re finished, you won’t know we were ever there.

”All of the tunnelling equipment from Nantmel will then be transferred to the third and final site at Knighton, where the Tunnel Boring Machine will be prepared for its third and final re-launch in April 2018.