Urban Utilities has begun the next stage of its Brisbane River pipeline upgrade, one of the utility’s most complex and unique capital works projects.
The scope of the project involves renewing a critical piece of wastewater infrastructure, 60m below the surface of the Brisbane River.
The Bulimba-Hamilton Siphon, which stretches under the riverbed from the southside of Brisbane to the north and consists of two large wastewater pipes inside a tunnel, needs to be taken offline for essential works to replace both pipes.
Urban Utilities CEO, Paul Arnold, said the next stage of the project was to install a temporary bypass pipeline so wastewater could continue to be transported across the river while the siphon is not in operation.
“The works to construct the 1km polyethylene pipeline began in mid-October 2024 and are progressing well,” he said.
“The pipe has been installed using the S-Lay method, which is commonly used for offshore projects, and was identified as the best approach due to the Brisbane River’s strong tidal changes and currents.
“The pipe sections are being welded together on a barge, gradually lowered onto the bed of the river and, under the guidance of specialised divers, secured in place with around 130, 4t concrete blocks.”
Planning for the bypass pipeline was part of the contingency planning for the project in 2023.
Mr Arnold said a temporary pump station was also required so wastewater flows could be diverted from the siphon to the bypass pipeline.
“The pump station will be largely underground, with the design and construction method carefully considered to reduce any impacts to nearby residents.
“Construction started in August, piling works are already completed and concrete works have started,” Mr Arnold said.
“Once the bypass pipeline and pump station are operational in early 2025, we will take the siphon offline so we can safely assess and repair a break in one of the pipes and continue works to replace the other pipe.”
Urban Utilities has carried out an extensive engagement program to ensure the success of this project and to support the community, by providing regular updates about how the works might impact them.
Featured image: Urban Utilities
