Managing for Excess Water

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Managing for excess water 

At our WAIO operations, water from the mine pit, which needs to be extracted to access the ore, typically exceeds the volume required for use by our mines.

Any excess fresh water extracted must be managed, and if not undertaken appropriately, can impact ecosystems and other users who depend on groundwater. WAIO’s preference is to return surplus water to the aquifer to minimise impacts to ecosystems, a process considered best practice for surplus water management. Returning water to the aquifer through the use of sumps and wells minimises the interruption to natural processes by avoiding surplus water being discharged to streams that naturally experience only an ephemeral or infrequent flow.

Developed in 2012, WAIO's Pilbara Water Resource Management Strategy evolved in 2015 to include the preliminary findings of further studies carried out with CSIRO and government bodies to consolidate water knowledge and characterise climatic variability, surface water flow, groundwater occurrence, movement and dependency on a regional context. The study is developing important reference datasets for common use by industry and regulators, particularly an understanding of future climatic variances for the Pilbara and the effects it has on the water resources. The preliminary study results support our view of the regional hydrological system, validating our environmental water assessments and catchment scale adaptive management plans. Our continued commercial and technical contribution to the Pilbara WRA study over the past three years demonstrates our commitment to external water stewardship.

To support water management plans, WAIO has set measurable targets relating to the volume of water returned to the aquifer and monitoring to provide early warning of hydrological changes.