Quick thinking, state-of-the-art technology and teamwork spared a key South Australian local road from a serious closure and weeks of costly roadworks.
Late on a Friday afternoon in June 2020, Civil Maintenance and Construction teams from City of Onkaparinga, on Adelaide’s southern fringe, suddenly realised the surface of Galloway Road in O’Sullivan Beach, which crosses Christie Creek, was at risk of partial collapse.
CCTV revealed that four corrugated iron pipes (or culverts, which allow water to flow under the road) had significantly deteriorated, and with rain forecast for the following evening, time was of the essence.
Council’s Construction Project Officer, Iestyn Broomfield, said, “Keeping water out of the collapse site was critical.
“Culverts provide drainage to support the wellbeing of the surrounding environment, preventing erosion and allowing aquatic wildlife to move freely through the waterway.
“It can be enormously costly, damaging to the environment and very inconvenient to road users when they collapse.”
With more than 5000 vehicles using Galloway Road – the only access across Christie Creek for O’Sullivan Beach – each day, Council staff knew they had to find
a novel solution.
“We moved quickly to collaborate with teams across the organisation, using road plates as an interim measure and monitoring the site around the clock to identify any deterioration to the embankment supporting the road.
“This collaboration was crucial in preventing Saturday’s rain from affecting the road’s structure.”
Council engaged leading water infrastructure company Interflow to develop a longer-term solution using technical analysis, engineering and survey.
In a first for South Australia, the Interflow team and Council used a Rotaloc to wind a PVC liner inside the damaged pipes to repair their structure.
With concerns about the safety of crew members required to enter the pipes, the Rotaloc’s hydraulics were modified to operate remotely, allowing it to perform the first remote use of the machinery in the state.
Broomfield estimates the culverts have been secured for the next 50 years.
“It’s amazing what you can achieve when you combine teamwork with out-of-the-box thinking and innovative technology.”
