Civil-Dewatering-Tug Harbour Project, WA

NPE were contracted to perform dewatering work and water treatment for the development of new Tug Harbour and material offload facility at Hunt point on Port Hedland’s Finucane Island. The new Tug Boat Harbour will house an extra 8 tugs, serves to lay some of the foundations for a massive outer harbour expansion in the near future. Our scope of works involved the design, supply, installation and maintenance of dewatering system for the highly challenging harbour project, where a 250m x 250m excavation was planned to be constructed, 22m below ground level and 16m below sea level inside a highly permeable rock wall. 

Dewatering incorporated the drilling and installation of multiple bore holes, welding and positioning of two ring mains circling the entire construction zone using the 355mm diameter pipes, for a total of 2.5 km of pipe works installed. The primary focus was to keep the excavation area 16m below sea level dry while excavation works are in commencement. The dewatering set up has a pumping capacity of 24,000 m³ per day. On top of that, water treatment set up were also part of project requirements with the extracted water treated via the chemical dosing unit prior to discharge into the sedimentation ponds and the ocean. 

NPE’s dewatering was so successful that a water cart was needed in the base of the excavation in order to minimise the dust 16m below seal level.