Following severe erosion starting with 2011 floods, erosion has exposed the Rocklea to Kuraby DN1200 water main at Sunnybank. Further erosion poses a risk of collapse of the water main into the adjoining Stable Swamp Creek. The Project required construction of a new 5.5 high gabion wall to protect the water main and reduce the risk on any future erosion.
The objective of this project is to reduce the risk of continued erosion and/or undermining, leading to failure of the water main, and subsequent disruption to water supply, along the Rocklea to Kuraby DN1200 water main at 258 Beenleigh Rd, Sunnybank.
Seqwater required a principal contractor for the installation of creek and pipe protections to mitigate further erosion, and provide a support to the exposed section of pipe, through implementing the below:
This objective was achieved by re-profiling the creek bank to achieve a sound foundation and placing gabion baskets terraced up from the creek to prevent future erosion. Before these works commenced, the DN1200 water main was supported to ensure it is stable and prevent any movement during the construction period. Bellwether also engaged an RPEQ to design, inspect and certify the support system for the water main.
The system involved the installation of ground anchors which stabilized the bank and supported the main during construction. This system involved no permanent attachment to main and did not damage the coating to the pipe. Furthermore, this system also provided a safe, stable bank for our crews to work under whilst installing the permanent footings and gabions.
Bellwether ensured the integrity of the water main through a two-fold process. Firstly, we engaged an RPEQ to design, inspect and certify a support system for the main. Bellwether also allowed for a qualified surveyor to monitor the main so that in the unlikely event that the main did move, we could halt construction immediately. This secondary measure provides certainty that the water network remained operational throughout construction.
Other key concerns involved with the delivery of these works include ensuring zero harm to workers and minimizing environmental impacts. We achieved zero harm to workers by implementing Seqwater’s lifesaving controls alongside Bellwether’s own ISO accredited safety system to assess and mitigate the risks during construction.