Detailed design for a pump station and 21-kilometre pipeline

Hope Downs 4 Dewatering Pipeline Project

The Hope Downs 4 (HD4) site has several high-grade iron ore deposits—a significant percentage of which are below the water table. To successfully mine this ore, the proposed pits needed to be dewatered. Water balance assessments showed the site water supply exceeded demand, so up to 120 megalitres of surplus water needed to be discharged from ongoing mine operations every day.

We were brought in to complete the detailed engineering design for a pump station and a 21-kilometre (13-mile) pipeline to discharge the daily surplus from the raw water pond at the HD4 site to a discharge outlet at Kalgan Creek. Our design work also included transformer requirements for the pump station and associated cabling, lighting, instrumentation, and controls.

The pipeline needed to traverse mine operations and haul routes as well as challenging terrain—approximately 85 minor water courses. To achieve a cost-effective design, we addressed route optimisation early in the piece and shared the primary option with site operations to get buy in. Additional site data gathering assisted in refining the design, optimising the earthworks, limiting road and pipe interfaces, and reducing environmental impact.

Now complete, the pump station and pipeline have made a significant amount of high-grade iron ore deposits accessible at the Hope Downs 4 mine site.