Harpers Hill Reservoir and Lochinvar Trunk Main Upgrade
About the project
The Harpers Hill Reservoir forms part of the Maitland/North Rothbury water supply system in New South Wales, Australia. The volume of the existing Harpers Hill Reservoir provides limited capacity to the overall system, with a high drawdown and fill frequency. Pensar designed and constructed a new 7 ML potable water reservoir and pipework system, including the extension of Harpers Hill Lane, and constructed a 2.4 km trunk main. The upgrade enables Hunter Water to strengthen its water security, supporting regional growth for the next 15 to 20 years.
Location
Harpers Hill, New South Wales
Client & Duration
Hunter Water
Jan 2024 - Feb 2026
Project Scope
- Separable Portion 1 included the demolition of the existing reservoir and disposal of materials, the design and construction of a new 7ML potable water reservoir, pipework, control upgrades, access road upgrades, geotechnical investigations, testing and restoration.
- Separable Portion 2 included construction of 2.4km DN375 PVC trunk main from the Lochinvar Pump Station to the new reservoir along the New England Highway, including
two under road bores.
Challenges
- Management of multiple services within road reserve during design and construction phase
- Mitigating the effects to the program and budget / resourcing during significant wet weather events during civil works
- Due to exposure of significant artefacts found underground during works, subsequent heritage management was required
- Health and safety management was required to mitigate the unexpected exposure of asbestos in ground during works
- Careful planning and consideration were required to meet logistical challenges of concrete pour and quality of undertaking an 8-meter high in-situ wall, half circumference of reservoir, in one lift
- Due to high winds on an exposed site and adverse weather impacts, Pensar needed to pivot and adapt the program to cater for unprecedent amounts of inclement weather
- Management of unknown underground services.
Achievements
- Targeted planning and procurement have allowed Pensar to accelerate program and deliver Separable Portion 2, six weeks ahead of date for practical completion on an original 35 week program
- Early engagement of stakeholders and acceleration opportunities have been taken up in Separable Portion 1, and we are targeting a completion ahead of the original 71 week program
- Positive subcontractor relations achieved through engagement and transparency, as well as responsive approaches to feedback both ensured and enhanced the quality of work and working environment.