River water, via Murray Bridge to Onkaparinga pipeline, to Adelaide Hills from 1973; pumped by solar grid from 2022

The pipeline carring raw water from the South Australian River Murray city of Murray Bridge to Onkaparinga and the Mount Bold Reservoir in the the Adelaide Hills. At right: The array solar of 34,000 solar panels (see location. Top right, near Rocky Gully and Murray Bridge) providing electricity for pumping the water through the pipeline.
Images courtesy SA Water and Wikipedia (by Fairv8)
South Australia’s Murray Bridge-to-Onkaparinga 50 kilometre pipeline, almost half underground, was the second pipeline built to supply Adelaide metropolitan area with raw water that was treated at Happy Valley reservoir and other plants.
Completed in 1973, it carried water from just north of Murray Bridge to the Adelaide Hills’ Mount Bold, the largest reservoir in South Australia, with a capacity of 46.6 gigalitres. Mpunt Bold reservoir wasn't directly connected to the water network. Its water was released as required to maintain an adequate level at the Clarendon weir where water was diverted to Happy Valley reservoir and its treatment plant. Water from Murray Bridge-to-Onkaparinga line also went to South Australia government-owned SA Water’s water treatment plants in Kanmantoo and Balhannah in the Adelaide Hills.
The Murray Bridge-to-Onkaparinga pipeline had more than 34,000 solar panels installed in 2022 to provide electricity for its second pump station near Rocky Gully. The large photovoltaic panels generated around 25,600 megawatt hours of cleangreen solar electricity per year.
SA Water’s senior manager of Zero Cost Energy Future, Nicola Murphy, said the site achieved a carbon emissions reduction of around 11,000 tonnes each year: “The annual solar generation capacity is significant, with the 34,272 panels able to generate the equivalent energy capacity to power more than 4,000 average South Australian households. When you consider our annual electricity expenses reached more than $80 million in recent years, being able to harness large-scale renewable energy assets such as this will help to make a difference in reducing these significant costs over the coming years.”
SA Water’s Zero Cost Energy Future initiative saw more than 360,000 solar panels installed across 33 SA Water treatment plants, water tanks, pump stations and depots across South Australia.