Huntingdale Sewer Infrastructure Dewatering Project

The Huntingdale dewatering project involved installing more than 1.2 km of new sewer infrastructure along the environmentally sensitive banks of Wungong Brook, between Rusthall Way and Bullfinch Street in Huntingdale, WA. Because the construction footprint followed a natural waterway and moved through several different soil types, the project required a carefully planned dewatering and environmental management strategy.

To support the overall construction schedule, the NPE Environmental team developed a comprehensive Site‑Specific Dewatering Management Plan. This was prepared in conjunction with the existing Acid Sulphate Soil Management Plan to ensure all environmental criteria, monitoring requirements, and compliance obligations were clearly defined. The plan helped guide decision‑making on groundwater abstraction, discharge management, and adaptive environmental controls during the works.

Dewatering Requirements and Methodology

Across the alignment, dewatering was required for more than 30 drill and receival pits, as well as multiple sections of open trenchingreaching depths of up to 5.2 m below ground level (BGL). Because ground conditions varied significantly, NPE adopted a flexible approach that alternated between wellpoint dewatering systems and open pumping methods. This ensured groundwater control was maintained safely and efficiently across all excavation zones, regardless of changes in soil structure, permeability, or trench alignment.

Project Outcome and Continued Works

Despite the challenges presented by working near a waterway and encountering variable geological conditions, the project was delivered successfully over a 5–6 month period. The effective performance of the dewatering systems, combined with proactive environmental monitoring, enabled excavation and installation works to progress without delay. Due to the successful delivery of this stage, NPE was awarded the next phase of works, which is now underway and continues to be actively dewatered in line with the project requirements.