Watermain Diversion Project, Maroochy Airport
Project Watermain Diversion Project at Maroochy Airport, Marcoola
Client Unitywater
Location Sunshine Coast, QLD
Scope
Dormway was engaged by Unitywater to construct 2.7km of 710mm diameter PE PN16 water pipeline to enable the trunk water supply to be diverted around the expansion of the Sunshine Coast Airport. This included a 500m section of open-trench construction within marine clay in a narrow corridor between tree protection zones.
Works included excavation within a wet semi-estuarine environment, butt welding of the entire pipeline, installation, live works cut-ins to the existing network, testing of the pipeline to 1650 KPa and progressive site reinstatement, which expedited the return of the surrounding area to its original condition.
Outcome
Through our constructability reviews, Dormway was able to add value by suggesting design changes which reduced operational and maintenance risk for Unitywater.
Despite the various challenges encountered, Dormway leveraged off our past experience constructing in these types of environments in order to mitigate risk on the project, with the end result being the successful delivery of the pipeline three weeks ahead of schedule.
Challenges
- Narrow construction corridor within an environmentally sensitive area including significant flora, fauna and tidal drainage channel
- The challenging construction environment also included Acid Sulfate Soils, works adjacent to high voltage overhead powerlines and several tidal creek crossings that were only accessible during low tide
- Extremely wet ground conditions affecting trench stability, with pipe trenches located in a low lying semi-estuarine environment
- Challenges traversing plant and equipment around the site following rain events