New South Wales Water Minister Phil Costa said that in a world first, 1,200 individual lengths of 12 metre diameter cement steel pipe, weighing 30 tonnes each, have been laid simultaneously in a string and placed in an underwater trench.
“Using a purpose built lay-barge, seven kilometres of twin pipe have been laid underwater with pipeline now crossing the entire length of Botany Bay,” Mr Costa said.
The twin pipeline is expected to be connected to a single 1.8 metre diameter pipe that has been laid offshore from Silver Beach, Kurnell. Three tunnel boring machines had been used to microtunnel an 800 metre section to minimise the disturbance to residents and also to protect unique tracts of seagrass along the Botany Bay floor.
The $A650 million, 18 kilometre pipeline and its associated infrastructure and systems will carry the desalinated water from Kurnell, across Botany Bay, to the city’s main water supply, the City Water Tunnel at Erskineville. The pipelines will initially transport 250 million litres of drinking water a day from the desalination plant and can carry 500 million litres of water a day if required in the future.
To date, the desalination plant is 85 per cent complete, with the project on time and within budget.
