The Early Works package for the Prince of Wales Hospital Acute Services Building is nearing completion. The civil infrastructure upgrade utilises the topography of the area to divert stormwater around the site periphery, protecting the $720 precinct from flood during extreme weather. ACOR Consultants was appointed to undertake Civil Engineering and Water Services Coordination for the works. The initial assessment of the State Significant Development Application raised a number of issues that needed to be addressed with regards to the drainage infrastructure. Brought on board at the detailed design stage, the ACOR civil team identified a number of solutions, working closely with the building contractor Lendlease, flood modeling experts BMT, Sydney Water, RMS and Randwick Council to address operational and environmental impacts.
Key challenges included flood mitigation, digging in rock, dust mitigation, management of overland flow and water services coordination to ensure seamless interface with the existing infrastructure. A new 3,500 cubic metre flood storage tank has been constructed and is a key component of the site stormwater and flood protection strategy. The new system stores runoff in large precast concrete modular chambers (Humes StormTrap system) approximately 5m underground, before releasing water at a controlled rate and diverting it around the site along Botany Street. Supersize pits have also been installed on the corner of Botany and High street, with a Sydney Water manhole positioned in its centre, to allow access to the sewer a further 2 metres beneath the stormwater drainage invert level. The ongoing light rail construction and the need to the minimise disruption to both the main Hospital and UNSW added further complexity to the design and delivery. The team has maintained a regular on-site presence throughout the 6-month construction program, providing construction advice and responding to clarifications.
The early works package will be completed in October 2019 with the main works for the Acute Services Building already underway. The 9 level facility, designed and master-planned by BVN is located at the southern end of the 18,000m2 precinct. Procured under the ECI model, Lendlease has been appointed to continue with the construction of the main works. The remaining civil works includes construction of on-site detention systems, as well as pavements and access roads to the south and east of the site. To the east, there are plans to cut through 5m of gradient on Hospital Road to enable a future extension to the basement and surrounds, whilst McGill Street is being regraded to improve access to the site. As part of the continued precinct redevelopment, the Civil infrastructure has been designed with future-proofing in mind. Construction of the Acute Services Building is anticipated to complete in 2020 with the north area of the site earmarked to accommodate the expansion of the Children’s Hospital.