Protecting water resources and biodiversity at Innawally Pool

Our approach to environmental management is to minimise adverse environmental impacts by identifying, assessing and managing environmental risks across the life cycle of our operational activities, from pre-approval to closure.

As defined in the Our Requirements for Environment and Climate Change standard, each of our operated assets is required to assess risks and put in place controls that reflect the mitigation hierarchy (below), an approach that helps us to avoid potential adverse environmental impacts and, if necessary, minimise and rehabilitate any unavoidable impacts. If, after application of the first three stages of the mitigation hierarchy, actual or reasonably foreseeable adverse impacts to important biodiversity and/or ecosystems remain, we will seek to identify compensatory actions, such as offsets, in line with BHP’s risk appetite.

The mitigation hierarchy can be applied at any phase in the life cycle of our operational activities: before we undertake mining activities; during operation; and post-closure.

What is the mitigation hierarchy?

Avoiding impacts to Innawally Pool during mining operations at Jimblebar

Innawally Pool is a near permanent natural surface-water pool located within the footprint of Western Australia Iron Ore (WAIO) operational activities at Jimblebar.

It is located on Jimblebar Creek in a semi-arid climate with rainfall of 300mm per year and typically records flow events two to three times per year. The creek path is confined as it flows through the erosion-resistant Ophthalmia Range, resulting in the formation of an incised gorge. As the creek waters leave the gorge with high velocity, they have created the Innawally Pool, which is 700 metres long and 30 metres wide. The pool has adequate depth and storage in the underlying geology to retain water throughout the year.

Water bodies such as this require a rare combination of hydrology and geology and are uncommon in the Pilbara. Surveys of Innawally Pool conducted by BHP have shown that it supports a persistent population of Steindachner’s turtle (the only freshwater turtle known from the Pilbara), a high abundance of native frogs and over 70 species of invertebrates.

Following a review in 2018, BHP decided to re-think the mine plan for Jimblebar to avoid disturbing the Innawally Pool, in line with our commitment towards leadership in water stewardship, minimising adverse environmental impacts through every stage of our operational activities and contributing more broadly to the resilience of the natural environment. Furthermore, previous consultations identified that Innawally Pool had historical significance to the Nyiyaparli people. The benefit of not disturbing the pool also included avoiding loss of amenity for a broader area where other sites of significance had been identified, all of which contributed to our decision.

An engineering review of a potential creek diversion to access the ore underlying Innawally Pool determined that while it would be possible to transfer the flow downstream, it would not be possible to replicate the pool. We determined that due to the unique natural values of the creek and pool and the potential adverse environmental impacts, which in some cases could have been irreversible, our proposed mine plan did not satisfy the Our Requirements for Environment and Climate Change standard, so we changed the mine plan to avoid disturbance of that area.

To ensure this decision was formally embedded into future mining plans, WAIO voluntarily included the protection of Innawally Pool in the Jimblebar closure management plan. As a result, in May 2020 we resubmitted reserve estimates for Jimblebar that excluded the ore under the pool.