M3 motorway tunnelling breakthrough
A major new water supply pipe for Hampshire has taken a big step forward after its tunnel was completed deep beneath the M3 motorway – with no impact on motorists.
Drivers on the M3 were blissfully unaware that 7 metres under their tyres, a tunnel boring machine (TBM), has dug a tunnel for a project called the Southampton Link Main, which will boost resilience for our water supply across Hampshire.
The TBM started work on 6 October and finished the tunnel underneath the M3 motorway on 6 November.
The M3 motorway tunnel is one of three tunnels that, when complete, will be connected and run to our Otterbourne site.
Terence Hedley, Senior Project Manager, said:
“It’s so exciting to reach another important milestone in the development of this essential project. It’s a key part of our plan to create new drought-proof sources of water for Hampshire and help keep the county’s taps and rivers flowing.
“The tunnel boring machine worked 24/7 digging its way underneath the M3 motorway for 32 days. The tunnel has an internal diameter of 1.5m and the machine was operated remotely above ground.”
Once complete, the new 19km underground pipeline – called the Southampton Link Main - will run from our Otterbourne Water Supply Works to Yew Hill reservoir, near Winchester, and then south to our Rownhams Water Supply Works on the outskirts of Southampton. This will boost resilience for our water supply across the county.
The project, which is expected to cost more than £100 million, began earlier this year and will take around three years to complete.
