Detailed sequencing of the works was required to be developed, to ensure that the water supply to the Mt Pleasant reservoirs was maintained during the contract.

 

The work has been a long time in planning, with investigation works completed early 2024 to identify the existing buried utilities, most notably the adjacent high voltage transformer and cables. Our engineers surveyed and mapped the existing utilities and designed a suitable 3-dimensional pipe alignment, essentially ‘threading the needle’ to ensure the new pipeline could get from A to B without any obstructions.

 

From the 3-dimensional design, the 2x 51m pipelines were broken up into a total of 43 bespoke pipe and bend sections, these were fabricated to exact tolerances and to a pressure rating that’s three times the standard pipe rating, due to the increased pressure the pipes are under on the hill. A detailed construction methodology was developed to ensure the installation sequence achieved the required installation tolerances, as there is no ability to bend the steel watermains.

 

The pipelines are installed vertically up a cliff face which required the design and construction of rockfall mitigation netting and rock anchor bolts to restrain the pipeline. Our staff and specialist subcontractors completed this by abseiling and scaling the rock face.

 

This project is crucial for enhancing the reliability and capacity of the local water supply network, ensuring long-term benefits for the Mt Pleasant community.