SA Water has announced that new large underwater pipelines are now in place off the coast of Penneshaw, marking a major milestone in the completion of the Kangaroo Island desalination plant.
Constructed in Kingscote with South Australia-based company Maritime Constructions before making the journey to Penneshaw, the 200m-long submerged pipelines include two intake pipes which will draw in seawater for treatment into safe, clean drinking water at the new, two million litre-per day-capacity desalination plant near Hog Bay Road.
The third outfall pipe will return saline concentrate from the desalination process to the ocean, in accordance with strict environmental guidelines.
SA Water’s Senior Manager of Capital Delivery, Peter Seltsikas, said that the new underwater infrastructure is adjacent to the existing smaller desalination plant on Desal Drive.
“The complex process of getting the high-density polyethylene pipelines in place was quite the effort, with crews taking around five hours to safely tow the infrastructure from the Kingscote jetty and into position using a large barge vessel,” Mr Seltsikas said.
“We also needed to time these works with the unpredictability of weather, with the crews requiring around three days of ideal tidal conditions to safely transport and sink the pipes to the ocean floor.
“We have the expertise required to successfully construct and operate a desalination plant like this without impact to the surrounding impact environment, having successfully operated the existing facility in Penneshaw for almost 25 years.
“With this important milestone ticked off, we’re now working to complete the remaining marine works and connect the pipes ahead of the plant producing first water from the middle of 2024”
SA Water has also completed the construction and testing of more than 50km of underground water trunk main spanning from Penneshaw to the utility’s existing Middle River water supply network.
Once operational, the pipeline will deliver drinking water produced from the new seawater desalination plant to people living in American River, Island Beach, Baudin Beach and Sapphiretown.
“Stretching a total of 50km, the ductile iron cement-lined pipeline is among the largest underground trunk main constructions we’ve completed in recent years,” Mr Seltsikas said.
“Having completed the extensive design, construction and testing required for a main of this size and scale, to now have the entire length of underground pipe ready for action is a positive achievement.”
Featured image: One of the pipelines. Image credit: SA Water.
