For information on the role of the BHP Board in overseeing our approach to and delivery on sustainability, refer to the Sustainability approach webpage.
We use our Water Position Statement, our water stewardship strategy and our standards (Our Requirements for Environment and Climate Change standard, Water Management Standards) to manage water at BHP. Each of our operated assets has assigned accountability and responsibility for its key water management activities and this is a requirement of our Water Management Standards.
Governance for our water activities is essential for us as water is integral to our business and vital to the longevity of BHP. We cannot operate without it. We use water in many ways, including but not limited to: 

 

• extracting it for activities including ore processing, dust suppression, ecosystem irrigation and processing mine tailings
• managing it to access ore through dewatering (extraction of water from below the water table to allow access to ore) and at our legacy assets (legacy assets refers to those BHP-operated assets, or part thereof, located in the Americas that are in the closure phase)
• providing drinking water and sanitation facilities for employees and townships
• discharging water back to the receiving environment
• interacting with marine water resources through our port facilities
• utilising marine water for desalination

For a more detailed example of how we use water in our operated assets, refer to our Olympic Dam case study.

As we use water in many ways and given the criticality of water to BHP, we have a responsibility to effectively manage and have governance over our water interactions and avoid or minimise our potential or actual adverse impacts on water resources. We also recognise the importance of working with others to enable more effective water governance and stewardship across the communities, regions and countries where we operate.

Effective water stewardship must begin within our operated assets. From there, we can more credibly collaborate with others toward solutions to shared water challenges. Responsible water management will ultimately make BHP more resilient and will contribute to enduring environmental and social value.

We must manage a variety of water risks and challenges. Water challenges faced by BHP may include water scarcity or high variability in water supply due to climatic conditions or cumulative use or impacts within a catchment. These challenges need to be managed appropriately to avoid or minimise actual and potential adverse impacts and support positive impacts to the environment, communities and BHP’s ongoing viability. We seek to identify and assess opportunities to reduce stress on water resources from our operations and to collaborate with others on challenges and opportunities like water scarcity or high variability in water supply. 

 

Specific governance that is in place for water is detailed below. These initiatives are in addition to the governance mechanisms and processes that are discussed for environment on the Environment webpage. The Our Requirements for Environment and Climate Change standard requires that our operated assets establish baseline water conditions, identify water-dependent receptors, water uses and stressors, and seek to predict changes to these conditions, including the potential impacts of climate change, for the ‘life of asset’.

Our operated assets are also required to determine their contribution to the current and future cumulative impacts and define thresholds and controls (e.g. environmental effects monitoring) to manage catchment-scale impacts, develop and review water forecasts over the life of asset, undertake a WRSA and develop operated asset-specific, context-based water targets. 

 

BHP has developed technical standards that set minimum standards for water management across its operated assets. These standards include the requirements for all operated assets, including legacy assets, to implement measures to avoid or minimise potential or actual adverse impacts to water resources and water-dependent ecosystems, communities and cultural values. 

The standards require development of:

• plans that incorporate initiatives that substitute, reuse and reduce our reliance on and potential adverse impacts to fresh water
• water balances that consider all primary water inflows, uses, treatment, storage, losses, diversions and discharges
• plans for management of excess water (storm water, dewater and runoff) to ensure a minimum tolerable level of impact to the receiving environment is achieved
• documentation of potential and known sources of groundwater and surface water contamination across the exploration, project, operating and closed sites
• a risk-based management program where there is potential for groundwater or surface water contamination or water quality impacts. The program must characterise the type, distribution and fate of contamination and establish water quality performance criteria in operational management activities (e.g. for excess water release or treatment)

BHP has established cross-functional teams to implement our approach to water stewardship at Group and regional levels. These teams include representatives from Planning; Engineering; Strategy; Health, Safety and Environment; Community; Corporate Affairs; Operations; Risk; and Legal.

In addition to regular stakeholder engagement processes, we undertake specific stakeholder engagement activities related to water stewardship. The following table outlines the key stakeholders engaged, how they were engaged and the topics on which they were engaged.

Our water disclosures here and in the BHP Annual Report 2023, Operating and Financial Review 6.13 - Environment have been prepared predominately pursuant to the ICMM Water Reporting Good Practice Guide (2nd Edition) (2021) (ICMM guidance)  minimum disclosure standard, which is an international water accounting framework that enables comparable water data across the mining and minerals sector. 

Our water reporting also considers other relevant frameworks. BHP is a signatory to the CEO Water Mandate and our disclosures here and in the BHP Annual Report 2023, Operating and Financial Review serve as BHP’s Communication of Progress against the core elements of the CEO Water Mandate. Our reporting is also consistent with the Global Reporting Initiative (GRI). For more information on how this webpage meets the GRI standard refer to our ESG Standards and Databook.

We have reported our water withdrawals and discharges and had water-specific public targets in place for more than 15 years since the establishment of the Minerals Council of Australia's Water Accounting Framework (WAF). 

We transitioned our reporting in FY2019 to align with the ICMM ‘A Practical Guide to Consistent Water Reporting’, and since FY2022 we have aligned our reporting with the updated ICMM guidance, ‘Water Reporting Good Practice Guide (2nd Edition)’.

The ICMM guidance and the WAF make use of a site water balance to establish a water account. The water balance approach is commonly used in hydrological studies to determine the flow dynamics of a system. A site water balance is a simplified water account where all water components are classified and those with common characteristics (e.g. consumed via evaporation) are aggregated to the highest possible level. The use of a water balance allows the generation of consistent site metrics for external reporting and provides a tool for effective water management for the mining sector. Site water balances are a live management tool that should be reviewed and updated on a regular basis. 

A generalised water balance ‘equation’ requires water inputs to equal the outputs plus any change in storage. That is: water withdrawals/inputs = water discharges + water consumption +/- change in water storage.

Water balance information has a variety of sources with differing degrees of accuracy. Following the WAF, information is classified as of high accuracy when measured directly or there are simulations with good accuracy over many reporting periods, or a forced balance in flows, medium accuracy when modelled or simulated using estimates based on historical data or coefficients. Information is classified as low accuracy when estimated or simulated using general coefficients.  

We recognise water balances contain a degree of uncertainty and, over a given period, the reported withdrawal may not be in balance with the sum of discharge, consumption and net storage change. The ICMM guidance requires that, at a site level, the delta storage derived by mathematical balance broadly reconciles with the actual change in volume of water in storage over the same period. This infers there is some allowance for uncertainty in the balance if actual changes are measured while other components of the balance are estimated, and comparison is considered a useful check for validating site data. Therefore, the balance should be reviewed and potential lags or uncertainties in the water system should be considered when assessing validity.

The general practice in the mining sector (in accordance with the ICMM guidance and WAF) is to force a balance in water accounts, such that withdrawals/inputs equal discharges plus consumption plus or minus change in storage, by creation of a balancing point, for example assumed evaporation or change in storage volumes.  

We have elected not to artificially adjust any dimensions of the water balance to force a balance in water accounts at our coal assets (BHP Mitsubishi Alliance (BMA) and New South Wales Energy Coal (NSWEC)), where storage changes are potentially large. At our coal assets, we have chosen to retain the calculated differences in the water balance and recognise the differences represent levels of uncertainty within the water balance. This understanding of uncertainty is considered in our ongoing water management decisions and guides the ongoing improvement of our water balance models, which are continually developing as we apply new measurement points, enhanced measurement methods, and improved practices to estimate indirect data (for example the runoff from rainfall, evaporation and seepage volumes). This approach is aligned with the intent of frameworks, including the ICMM guidance, WAF and GRI, that recommend water balances be used as a live management tool that can identify ongoing improvement in water accounts.  

An improvement program commenced in FY2022 at our coal assets and continued in FY2023. There may continue to be relatively high uncertainty in the water balance of the coal assets until the key improvement program changes are complete and have had time to influence a substantial period of data. As we gain experience in measuring storage, runoff from rainfall, evaporation and seepage across all our operated assets, we expect to see uncertainty reduce, and there may need to be retrospective corrections to the data.

In line with our commitment to continuous improvement of our water accounts and data, we continue to review our assumptions for accounting for water metrics and refine our methodology in water models and water balances, recognising that water modelling and balances contain a degree of uncertainty. Water models and measurement techniques will continue to evolve and our understanding and knowledge will grow over time. Our focus in FY2024 will be a review and refinement of our water accounts and model at our Nickel West asset.

Our reporting metrics are in line with the ICMM guidance and defined in the BHP Annual Report 2023 Glossary, such that we report:

• water withdrawals (water intended for use by an operated asset) by source, by quality and by operated asset
• water consumption (water used by the operated asset) via the type of consumption (e.g. evaporated, entrained)
• water discharge (water returned to the environment) by destination, operated asset and quality
• other managed water (water actively managed by an operated asset but not used for any operational purpose) by quantity and quality
• water recycled/reused (water that is used more than once at the operated asset) by quantity 
• change in water storage (the net change in the volume of water stored over the annual period) for material water stores

Since FY2021, we have reported the proportion of withdrawals, discharges and consumption that occurred in areas of water stress, as defined by the World Wildlife Fund (WWF) Water Risk Filter physical risk ratings (see BHP and basin risk in the Water-related risk at BHP section for a full overview of this change) and since FY2022, we have aligned our disclosure of other managed water (previously called diversions) to the updated ICMM guidance, which included the change in terminology and disclosure of this metric by both quantity and quality.

We use the WAF accuracy statement to provide an indication of the accuracy for each metric by classifying them according to whether they are measured directly, simulated or estimated. We use the accuracy statement as one tool to identify data gaps and opportunities for more or improved flow measurement in our water balances that inform our water management decisions. Where possible, we endeavour to maximise direct measurement and minimise estimation. We simulate or estimate elements that are challenging to measure directly, such as evaporation, seepage from tailing storage facilities, and rainfall runoff quantity and quality. 

Based on our application of the WAF accuracy methodology, in FY2023 approximately 70 per cent of withdrawal and 90 per cent of discharge volumes were measured for a majority of sources for the majority of the year, therefore this data is considered to be at a high accuracy level. We also recognise the WAF accuracy statement is a guide and only one tool to evaluate data quality and identify opportunities for improvement. We continued to make other improvements to the quality of our water data during FY2023.

We seek to minimise our withdrawal of high-quality water. The WAF and the ICMM water quality categories do not completely align with the generalised definition of fresh water, which is typically classified on the basis of salinity alone and related to drinking water guidelines (with a threshold of 1,000 mg/L Total Dissolved Solids). The majority of the significant volumes of water accessed and managed by mining and metals operations is not for a drinking water end use and therefore using the drinking water definition of high-quality water for reporting purposes would place inappropriate emphasis on the relatively small proportion of water managed. The WAF and ICMM guidance defines more specifically high quality water for application to the mining and metal sector, which is water with low levels of salinity, metals, pesticides and bacteria and relatively neutral (pH 6-8.5). The definitions for water quality types are provided in the BHP Annual Report 2023 Glossary, and a detailed description is available in section 2.2.4 WAF. BHP has continued to group water quality into three categories in line with the WAF: Type 1 and Type 2 defined by the WAF equate to high-quality water defined in ICMM guidance, while the Type 3 WAF definition equates to low-quality water under the ICMM guidance.  

In FY2023, approximately 66 per cent of our water withdrawals consisted of water classified as low quality by ICMM definition. 

Water data

This section provides detailed disclosure of our various water metrics in line with the ICMM  guidance, GRI sustainability reporting Standards and the Sustainability Accounting Standards Board (SASB) Standards. To allow year-on-year comparison with FY2023 BHP operated assets, the water performance data presented here excludes water data from the following Discontinued operations: Onshore US assets (sold on 31 October 2018), BMC (sold on 3 May 2022); and assets in BHP's Petroleum business (merged with Woodside on 1 June 2022) to ensure ongoing comparability of performance. All water data currently excludes assets acquired from OZ Minerals, and we intend to include this data in our FY2024 disclosures. Definitions of water metrics, sources, types and detailed water data by asset are provided in our ESG Standards and Databook, in the Glossary of the BHP Annual Report 2023 and in the ICMM Guidance and WAF. We have presented data from FY2019 as this is when we commenced reporting of the metrics as per ICMM Guidance. Data has been rounded to the nearest 10 megalitres to be consistent with asset/regional water information in this webpage and with the BHP Annual Report 2023. In some instances the sum of totals for quality, source and destination may differ due to rounding. 

Since FY2021, BHP has used the WWF Water Risk Filter to describe basin risk for our operated assets as discussed on this webpage under BHP basin risk. Using the WWF Water Risk Filter, it was found that two (legacy assets – United States and Pampa Norte) of our 10 operated assets (20 per cent), as of the end of FY2023, are classified as being under high or very high water stress due to location. The data for these water stressed assets are shown in our ESG Standards and Databook.  

Water withdrawals

Water withdrawals represent the volume of water, in megalitres (ML) received and intended for use by the operated asset from the water environment and/or a third-party supplier. 

Water withdrawals for FY2023 across our operated assets increased by 1.5 per cent from FY2022 (from 402,610 ML to 408,540 ML). Note that the data does not include Petroleum, BMC or OZ. 

Our withdrawal of high-quality water (Type 1 and Type 2) increased by 17 per cent from 118,770 ML in FY2022 to 138,410 ML in FY2023. This increase is due to the inclusion of water to supply the new concentrator at our Spence operations. This water is supplied by a third party and we disclose this water as Type 2 as this is the quality as we receive it. However, the original source of this water is Type 3 or low-quality water. Increases in withdrawals of high-quality water also increased at our BMA (climate conditions) and Western Australia Iron Ore WAIO. The proportion of high-quality water as a proportion of total withdrawals was 34 per cent, similar to FY2022. Total water withdrawals from operated assets located in high or very high water-stressed areas (as determined by WWF Water Risk Filter) was 29,710 ML (7 per cent of total withdrawals for BHP operated assets) and consisted of 63 per cent high quality (Type 1 and 2) water. This is a significant shift from FY2022 due to the fact that Escondida is no longer a water stress area, as determined by the WWF Water Risk Filter but our Legacy Assets located within the United States are. 

The majority of our water withdrawals (52 per cent) came from seawater, noting that some of the third-party water from Nickel West and Pampa Norte is sourced from desalination facilities, some of which are supplied by seawater. Currently, most of Escondida’s operational water consumption is met by desalinated water.¹ The proportion of withdrawals relating to groundwater across BHP’s operated assets remained relatively stable, from 22 per cent of withdrawals in FY2022 to 23 per cent of withdrawals in FY2023. WAIO and BMA account for approximately 60 per cent of ground and surface water withdrawal across our operated assets. 

The withdrawals and the material contributors to these were within expectations for FY2023 and in line with our ambition to minimise our withdrawal of high-quality fresh water and replace these with seawater/low-quality withdrawals where feasible. As the results are within expectations, we do not anticipate any implications for current commitments, strategy or costs for the business with respect to water withdrawals aside from those related to delivery of the context based water targets.  

The availability of water for multiple uses was identified through WRSA as a shared water challenge in the majority of the regions where we operate. To address this challenge, a number of our assets have released context-based water targets that may assist in reducing our withdrawal of water from the environment or increase water supplied from low-quality sources (such as seawater) by either increasing efficiency of water used for operational purposes, maximising return of surplus water (without use) to the environment (called ‘Other managed water’ by ICMM Guidance) or share/return our licenced water allocations to others. For example at BMA we have a target to support water stress reduction in the Fitzroy Basin through better use of water in our operations.   

Water discharges 

Water discharge includes water that has been removed from the operated asset and returned to the environment or distributed to a third party. This includes seepage from tailings storage facilities to groundwater, discharge from operations to surface waters (which are also affected by periods of higher rainfall) and discharge to seawater. Water we treat and then on-supply to third parties is captured as diverted water consistent with the ICMM guidance as it is not intended for operational purposes. 

Total water discharges for FY2023 were 140,370 ML, a minor increase from 139,600 ML in FY2022. Total water discharge in high or very high water-stressed areas was 2,630 ML, 100 per cent of which was Type 3/low-quality water. Eighty-eight per cent of our total discharges were from Escondida, which is the bi-product of desalination via reverse osmosis of seawater. Only 10 per cent of our discharges are comprised of high-quality water. 

Discharge to surface water (usually riverine systems) is influenced by climatic conditions such as rainfall and occurrence of extreme weather events, and therefore is subject to higher variability and is less predictable. Water management practices at our operated assets where this may occur are designed to accommodate this variability. Therefore, the occurrence of such events is not anticipated to affect our current management activities and strategy or result in elevated exposure to risk.  

In FY2023, 22 per cent of our operated assets did not discharge water as their water was either consumed in operational activities or reused/recycled. This is lower to previous years due to our NSWEC asset undertaking discharge due to high rainfall for the first time in many years and Pampa Norte due to the new concentrator.   

Water recycled/reused

The ICMM guidance defines reused water as water that has previously been used at the operated asset that is used again without further treatment, and recycled water is water that is reused but is treated before it is used again. 

During FY2023, the total volume of water recycled/reused was 344,710 ML. The amount of recycled and reuse to total withdrawals is 84 per cent. 

The ability of our operated assets to reuse and recycle water varies depending on the recovery processes used and the water quality requirements. The accuracy of the recycled/reused metric currently varies depending on the complexity of the process and how closely water movements are measured and understood. As our data collection and analysis improves, we expect to be able to more robustly assess opportunities to recycle or reuse water.   

Other managed water 

Other managed water (previously called diverted water) is water that is actively managed by an operated asset but not used for any operational purposes. For example, we withdraw water and treat it for use as drinking water by local communities, such as in the town of Roxby Downs in South Australia. In FY2023, 91, 220 ML of water was withdrawn without any intention to be used at BHP operated assets, and 31, 400 ML of this was in water-stressed areas. The majority of the other managed water is Type 1 and, in water stressed areas, 23 per cent was high quality (Type 1 and 2).  

Most of our other managed water comes from treatment processes in our legacy assets in North America and dewatering at WAIO (which is described further in the WAIO water case study).  

As the withdrawal of Other Managed Water may occur in a different reporting period to its discharge, in any given annual period there may be a differential between withdrawal and discharge volumes for Other Managed Water. In FY2023, we discharged 61,000 ML of Other Managed Water.  

Water consumption

In FY2023, evaporation and entrainment remained the most significant contributors to consumption. Evaporation occurs during a number of operational activities, including dust suppression, storage of tailings and storage of water. 

Evaporation consumption is inherently linked with climatic conditions. Evaporation data is estimated or simulated using average climatic conditions and therefore consumption due to evaporation should remain relatively stable. Due to the link with climatic conditions, the volumes consumed via evaporation are mostly outside of BHP’s direct control. 

Entrained water includes water incorporated into product and/or waste streams, such as tailings, that cannot be easily recovered. Entrainment may show variability due to the type and location of ore during any given reporting period. The use of water in our processing facilities, or for reducing dust release during storage of product can result in entrainment of water.   

The category of ‘other’ for consumption includes several uses, the most significant being water used by people for drinking or ablutions at operated assets.  

The collation and disclosure of consumption will assist in identifying areas for improvements in data accuracy for entrainment and evaporation, and assist with identifying opportunities to reduce, where possible, loss of water. For example, in FY2022 we commenced further analysis of our Nickel West consumption data. Once completed, we anticipate we will be able to more accurately reflect on the type of consumption (e.g. volumes consumed via evaporation and entrainment) of water within this operation. 

Total water consumption in FY2023 was 307,850 ML. Consumption in high or very high water-stressed locations was 33,710 ML (11 per cent of overall water consumption for BHP operated assets). The operated assets in FY2023 that consumed the most water were Escondida, WAIO and BMA. Entrainment of water in tailings is the largest contributor to consumption at Escondida, whereas evaporation is the key driver of consumption at WAIO and BMA mainly via evaporation from dust suppression, tailings and water storage. It should be noted that in any given reporting period, consumption and discharge volumes might be higher than withdrawals as evaporation can occur from water that has been captured and stored during previous periods.  

Changes in water storage 

The ICMM guidance recommends reporting of changes in water storage for clarity, as an indicator of internal water dynamics, and to provide increased transparency of all elements of a water balance. The ICMM recommends reporting of aggregate volumes for all sites within the company and for all sites within water-stressed areas. The ICMM, WAF and GRI recommend disclosure of changes in water storage when the volumes influence water-related decisions, have a significant water-related impact on the site, environment, communities or stakeholders, represent a material component of the site’s water balance or trigger significant changes in flows volumes or quality.  

The ICMM guidance requires that, at a site level, the delta storage derived by mathematical balance broadly reconciles with the actual change in volume of water in storage over the same period. This infers there is some allowance for uncertainty in the balance if actual changes are measured while other components of the balance are estimated, and comparison is considered a useful check for validating site data. Therefore, the balance should be reviewed and potential lags or uncertainties in the water system should be considered when assessing validity. 

As discussed above, we have elected not to force a water balance at BMA and NSWEC to assist us in identifying the opportunities for improvements in the accuracy of our water balances at these operated assets. During FY2023, improvement in our BMA and NSWEC water balance continued to be implemented. We acknowledge that this data still contains uncertainty and as a result, changes in data (including retrospective changes) may occur as we focus our efforts on the water balances at our BMA and NSWEC operated assets. 

As expected, the largest changes in water storage during FY2023 occurred at our BMA operated assets. This is where the majority of our water source is from rainfall and as discussed in the Water-related risk at BHP section on this webpage, is highly variable year to year. 

Water-related legal performance 

During FY2023, we had five incidents of water-related non-compliance that resulted in a formal enforcement action and one that resulted in a warning. Four of the enforcement incidents occurred at BMA, with one of the enforcement notices received in FY2023 in respect to an incident that occurred in FY2022. One incident related to releasing mine affected water, one to uncontrolled release of piped mine tailings and two occurred due to release of raw sewerage. One, enforcement action occurred at our Escondida operation and related to compliance with groundwater extraction monitoring requirements.  

In addition, a warning letter was received by our WAIO operations relating to the wetting front extent from discharges from our operations, with no further action from BHP required. 

Water-related legal issues are currently pending at our Minerals Americas operated assets. These relate to: 

• an environmental damage action related to the alleged impact to the Lagunillas aquifer, the nearby wetlands and lagoon at Cerro Colorado  
• regulatory proceedings for alleged non-compliances to Escondida’s approval governing the extraction of water from the Monturaqui aquifer  

These legal cases are still pending as of the end of FY2023. More information can be found in the BHP Annual Report 2023, Operating and Financial Review 6.13 - Environment. 

 

1 Small quantities of groundwater are extracted for pit dewatering to allow safe mining, and this water is used for operational consumption.

Next steps  

In FY2024, we intend to commence implementation of activities to achieve our existing CBWTs and milestones. We also intend to commence development of CBWTs for our remaining operated assets, and non-operational legacy assets. We plan to continue our collaboration on water governance and management with external parties and integrate OZ Minerals water disclosures with our disclosures.