Tunnelling Starts on Victoria's Desalination Project

Unlike most desalination plants around the world, Wonthaggi’s intake and outlet tunnels will be built 15-20 metres underneath sand dunes and the seabed which will ensure the marine environment is protected.

Work is about to start on the 1.5 km long outlet tunnel, while the first machine has bored 130 m of the 1.2 km long intake tunnel.

The custom-built tunnel boring machines are 4.8 m wide, 91 m long and weigh more than 500 tonnes each.

The tunnel boring machine will excavate through heavy rock and will line the tunnel with concrete segments as they move along. Both tunnels are expected to be completed early next year.

The intake tunnel will draw sea water into the desalination plant where it will be treated. The drinking water will be pumped to Melbourne and to connected regional water authorities, and the seawater concentrate will be discharged into Bass Strait via the outlet tunnel, where it can be easily dispersed.

Two local school students won a competition to name the tunnel boring machines. Jakob Moon, 6, from Traralgon, the son of a project worker, named the intake machine ‘Wonthaggi Maggie’ and Mycalie James, 18, from Bass Coast Specialist School named the outlet machine ‘Rocking Ruby’.