Installation has begun of around 50 kilometres of new large underground pipeline to connect Kangaroo Island communities with a new seawater desalination plant at Penneshaw.
The state government says it is building the treatment plan to "improve drinking water security and support the Island's tourism and agricultural industries".
The first stage of pipeline construction between Penneshaw and Pelican Lagoon will continue for the next several months, with regular deliveries of the 375-millimetre diameter pipes underway via ferry from the mainland.
Work on the new two megalitre a day capacity desalination plant is expected to then start in early 2022, at the corner of Hog Bay Road and William Walkers Way in Penneshaw, around 500 metres from the existing 400 kilolitre a day desalination facility, which has been supplying water since 1999.
Minister for Environment and Water David Speirs said the plant would supplement the smaller existing nearby facility and Middle River Reservoir, to deliver an additional climate-independent supply of drinking water for the Island.
"A desalination plant on Kangaroo Island will significantly increase water security, create up to 500 jobs and provide an economic boost to the region through improved agricultural and tourism opportunities," Mr Speirs said.
"The devastating bushfires in 2020 highlighted the water infrastructure issues faced on Kangaroo Island and this project will provide greater resilience for the entire Island in times of drought and bushfires.
"More than a thousand residents in American River, Baudin Beach, Island Beach and Sapphiretown will be able to connect to SA Water's network, gaining new access to a reliable supply of drinking water and an added layer of bushfire resilience.
"There will be strong support for the local economy during construction of the new desalination plant, with SA Water's stage one pipeline lead contractor Fleurieu Civil engaging with local businesses providing supplies like machinery, fencing, quarry sand and arborist services.
"The challenges presented by the Middle River Reservoir - a small, remote, climate-dependent supply - were highlighted during the bushfires on Kangaroo Island and reinforced plans to increase local drinking water reliability.
"While drinking water was maintained to the Island throughout the fire period, the higher than usual demand primarily from fire-fighting use, was only able to be met through network reconfigurations and carting water from Penneshaw and the mainland.
"Fire plugs will be strategically placed along the new pipelines into these communities, enabling fire authorities and water carters for the first time, direct access to water via SA Water's infrastructure in these areas, to fill or refill."
A total cost for the project has been revised to $64.9 million from $47.8 million, following significantly increased community demand in the new water supply.
This includes the installation of a larger size PVC trunk main to accommodate increased water demand and higher pressure, supporting more customer connection opportunities, as well as additional bitumen reinstatement and traffic management.
This increase in total project cost will be managed within SA Water's existing capital investment program for 2020-2024, along with the joint state and federal government contributions confirmed in 2020.
Subject to required development and environmental approvals, the new desalination plant is expected to deliver first water by the end of 2022.
For more information on the project, visit watertalks.sawater.com.au