Bothar has successfully completed a major sewer infrastructure project in Melbourne, further demonstrating the company’s capability to safely deliver complex trenchless construction and live asset works in challenging urban environments.
Delivered within a live operating sewer network, the project involved extensive tunnelling, shaft construction, bypass pumping operations, and multiple live sewer tie-ins — all completed while maintaining uninterrupted service to the surrounding network.
The works required detailed engineering, meticulous staging, and close coordination across all delivery partners to manage the significant technical and operational risks associated with live sewer infrastructure.
A defining feature of the project was Bothar’s successful management and execution of the live sewer tie-ins and major bypass pumping system.
These works represented the highest-risk components of the delivery and required continuous operational control, detailed contingency planning, and precise sequencing to ensure network integrity was maintained throughout construction.
The bypass pumping system was critical to enabling the works and involved the design, installation, commissioning, and ongoing management of sewer flows under live conditions.
At the same time, Bothar’s crews successfully completed a series of live sewer connections under highly constrained conditions, demonstrating the team’s technical expertise and strong focus on safety and operational performance.
The broader scope of works incorporated a range of specialised trenchless methodologies and supporting civil works.
These included excavation and support of four secant piled launch and retrieval shafts, along with a shored launch shaft to facilitate tunnelling operations and live sewer connections; installation of 430m of DN1400 GRP sewer pipeline using AVN microtunnelling methodology; and installation of a further 355m of up to DN500 GRP sewer pipeline using AVN microtunnelling, Vacuum Guided Boring, and auger boring methods to support associated utility relocation works.
Bothar also provided fabrication and installation of large-diameter GRP maintenance holes, including DN2800 and DN2500 structures, and demolition and modification of existing maintenance holes under live sewer flow conditions.
In addition to the installation and commissioning of the main sewer bypass system and completion of live sewer tie-ins, DN1200 sewer lift and relay works were completed under bypass conditions.
Construction of cast in situ maintenance holes and decommissioning of redundant sewer assets were delivered by Bothar as well as additional tunnelling works which helped support external utility relocations.
Bulk shaft backfilling works using flowable fill material were handled by Bothar, whose successful delivery of the project bolstered its growing reputation for undertaking technically challenging live sewer infrastructure works, particularly where complex bypass pumping and live tie-in execution are required.
Importantly, the project was completed on program and with strong safety outcomes, reinforcing Bothar’s commitment to delivering high-quality infrastructure solutions while maintaining the highest standards of safety and operational control.
As urban utility networks continue to require renewal and expansion, projects such as this emphasise the value of experienced trenchless delivery partners capable of executing complex underground works with minimal disruption to existing services.
Through this successful delivery, Bothar continues to strengthen its position as a trusted contractor for high-risk trenchless and live asset infrastructure projects across Australia.
For more information, visit botharboring.com
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