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, Sydney Water, RMS and Randwick Council to address operational and environmental impacts. Key challenges included flood mitigation, digging in rock, dusk mitigation, management of overland flow and water services coordination to ensure seamless interface with the existing infrastructure.

Supersize pits containing a modular StormTrap pipe system, are a key component of the stormwater strategy. The new system stores runoff in large precast concrete chambers underground, before releasing water at a controlled rate and diverting it around the site along Botany Street. A new 3,500 cubic metre flood storage tank has 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 7 metres beneath. Buoyancy testing was a crucial consideration to ensure the design would work to specification. The ongoing light rail construction and the need to the minimise disruption to 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 civils work 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 cross fall.

As part of the continued precinct expansion, 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.

Date: September 12, 2019