When One Mine Saves Millions of Liters of Water Daily

One copper mine’s decision will secure drinking water for one million people by 2030.

Los Bronces mine in Chile is ending all freshwater withdrawals, freeing between 14.7 and 43.2 million liters daily for communities in one of the world’s most water-stressed regions. This commitment represents the mining industry’s first large-scale attempt to operate entirely on desalinated seawater in a megadrought zone.

The stakes are enormous. Groundwater depletion has accelerated 17.8-fold since 1970¹. 19 million Chileans face severe water scarcity¹, and the 14-year megadrought shows no signs of ending¹.

Los Bronces’ transformation from water competitor to water provider demonstrates how industrial water cessation can simultaneously restore ecosystems and enhance community resilience. The case illuminates a pathway toward regenerative mining that respects planetary boundaries while meeting human needs—operating within the “safe and just space” between ecological limits and social foundations.

The model is replicable: 16% of global critical mineral mines operate in similarly water-stressed areas².

Chile’s water crisis meets mining innovation

A watershed under siege

Los Bronces sits in the heart of Santiago’s watershed, 65 kilometers northeast of Chile’s capital where six million residents depend on glacier-fed rivers now shrinking at unprecedented rates.

The mine draws from the Maipo and Aconcagua river basins—the same sources supplying 80% of Santiago’s freshwater—in a region experiencing the longest megadrought in a millennium¹. Groundwater tables have plunged 50 meters in a decade, and withdrawal rates have exploded 17.8-fold since 1970, driven more by overpumping (65%) than climate alone¹.

When scarcity becomes operational reality

Against this backdrop, Anglo American’s 2030 commitment to eliminate all freshwater withdrawals represents not merely corporate sustainability theater but operational necessity. Water scarcity forced Los Bronces to reduce throughput by 44% in 2023, directly threatening copper production at a mine holding 2% of global reserves³¹.

The crisis in numbers

Chile’s Water Stress Index now exceeds 100% in multiple basins, meaning water use surpasses available surface water—a physical impossibility sustained only by mining ancient groundwater reserves¹.

Key indicators paint a stark picture:

• Santiago faces a structural deficit of 250 cubic hectometers under dry conditions¹
• Nearly 500,000 Chileans already rely on emergency water trucks¹
• Glaciers feeding these systems have shrunk 98% this century¹
• Climate models project a 40% water reduction by 2070¹
• In Antofagasta’s northern mining region, mining consumes 64.1% of total water¹²

This concentration makes freshwater competition existential for both industry and communities.

A two-phase transformation

Los Bronces’ water transformation unfolds in two phases.

Phase 1 (launching 2025-2026) supplies 500 liters per second of desalinated seawater—43.2 million liters daily—through a $1.65 billion infrastructure investment³. This includes:

• 1,000 l/s coastal desalination plant in Puchuncaví
• 100-kilometer pipeline ascending to 3,300 meters elevation
• Capacity meeting 45% of operational needs

The project frees between 14.7 and 43.2 million liters daily (depending on rainfall) in the Maipo and Aconcagua basins³. It already benefits 20,000 people directly in Colina and Tiltil communities, with another 20,000 served along the pipeline route³.

Phase 2 (pending regulatory approval) proposes an innovative water swap: Anglo American provides 500 l/s of desalinated water for human consumption and receives treated wastewater for mining. This could secure drinking water for one million people before 2030³.

Transgressing ecological boundaries, failing social foundations

Beyond planetary boundaries

The Doughnut Economics framework reveals how mining in water-stressed regions simultaneously overshoots ecological ceilings while leaving communities below social foundations.

Planetary boundaries for freshwater have been transgressed as of 2022, making water the sixth of nine critical Earth system boundaries to be breached⁴. Globally, water stress stands at 18.6%, still below the 25% “safe” threshold, but this aggregate masks catastrophic regional failures⁴.

The regional picture is dire:

• Northern Africa exceeds 100% stress levels, withdrawing 18% more than renewable resources allow⁴
• Chile ranks 16th globally for baseline water stress¹
• Projections show “especially significant increases” by 2040¹

Environmental flow requirements

Scientific consensus holds that 37% of mean renewable freshwater should be reserved for ecosystems, rising to 60% during low-flow periods to maintain aquatic life and ecological functions⁴.

When mining and other users exceed these thresholds, rivers dry completely—already occurring in 25% of global river basins before they reach the ocean⁴.

Trapped between floors and ceilings

In Chile’s Maipo basin, extreme stress during 2010-2020 pushed withdrawals beyond sustainable levels while failing to meet human needs for the 19 million people living in severe scarcity¹.

The system trapped communities between floors and ceilings: insufficient water to meet the 20-50 liters per capita daily minimum for basic survival and hygiene⁴, while simultaneously depleting aquifers and degrading ecosystems beyond recovery timescales.

Social foundation gaps

The social foundation gaps expose structural injustice. Globally, 2.1 billion people lack safely managed drinking water—26% of humanity remains below the foundational threshold⁴.

In Chile, the crisis hits hardest in rural areas:

• Nearly 500,000 people depend on water trucks delivering as little as 15-20 liters per person for 1-2 days¹
• This falls far below the 100 liters per capita daily minimum set by Chile’s Supreme Court¹
• 47.2% of rural Chileans have no formal drinking water supply¹
• 80% of Canela municipality’s population relies on emergency deliveries¹

The health impacts are staggering. The WHO calculates that 1.4 million deaths annually are preventable through safe water, sanitation, and hygiene, representing 74 million disability-adjusted life years (DALYs) lost⁴. Water interventions reduce diarrheal disease by 34% and return $8 for every dollar invested in economic gains and health costs averted⁴.

Mining’s concentrated water footprint

Mining’s localized dominance creates these tensions. While mining accounts for just 4-7% of Chilean national water consumption, it commands 64.1% in Antofagasta region where copper and lithium extraction concentrate¹².

The global picture shows growing conflict:

• 16% of critical mineral mines already operate in high or extremely high water-stress areas²
• This is projected to reach 20% by 2050 as clean energy transitions drive mineral demand in precisely these arid regions²
• Copper mining alone withdrew 1.3 billion cubic meters in 2006 at approximately 90 cubic meters per tonne produced²

These are volumes sufficient to meet basic needs for millions—instead consumed in ore processing and dust suppression.

Desalination transforms water from scarce to abundant

Decoupling production from ecological limits

Los Bronces’ desalination strategy illustrates how technological interventions can decouple industrial production from ecological limits.

The mine currently recycles 90-94% of process water—near the industry maximum of 95%—yet cannot eliminate freshwater intake through recycling alone due to evaporation, dust suppression needs, and brine concentration buildup³⁵. Desalination offers the only viable path to zero freshwater withdrawal for coastal-accessible mines in arid regions.

Scale and feasibility

The numbers demonstrate feasibility at scale:

• Los Bronces’ 500 l/s Phase 1 capacity (43.2 million liters daily) provides 45% of operational needs³
• Expansion potential to 1,000 l/s³
• Chile already operates 12 large-scale mining desalination plants with 15 more planned⁶
• Collectively driving a 230% increase in seawater use over the coming decade⁶

BHP’s Escondida mine eliminated groundwater use entirely through 100% seawater desalination powered by renewables, while BHP’s Spence facility operates a 1,000 l/s plant—both demonstrating technical maturity².

Industry projections show Chilean mining reaching 47% seawater use by 2031 and targeting 66% by 2034, fundamentally restructuring the sector’s water footprint¹.

Plummeting costs

Desalination costs have dropped dramatically:

• 2000: $1.10/m³
• Today: $0.50-$2.00/m³ at the plant
• Delivered to mines: $1.00-$4.00/m³ (including pumping)⁶

Energy requirements have also fallen:

• 1970s: 20-30 kWh/m³
• Modern reverse osmosis: 3.0-5.5 kWh/m³
• Theoretical minimum: 1 kWh/m³⁶

Energy represents 50% of total costs, making renewable integration critical⁶. Chile’s cumulative investment of nearly $17 billion through 2030 in mining desalination infrastructure creates shared capacity that reduces per-mine costs and accelerates deployment timelines⁶.

The cost of inaction

The alternative—continued freshwater dependence—has become economically untenable.

Water scarcity already constrains production:

• Los Bronces reduced output 44% in 2023 due to insufficient water¹
• Water can cost up to $5/m³ for remote mines competing with communities⁶

When desalinated water at $1-4/m³ becomes cheaper than supply disruptions, production losses, and social license risks, the economic case closes. BHP and Codelco’s multi-billion dollar desalination investments reflect calculations that water security justifies premium costs when alternatives include mine shutdowns or community conflicts².

Communities gain what industry releases

Direct benefits: Water security for 40,000 people

The Phase 1 benefits quantify the social foundation gains from industrial water cessation.

Direct provision of 25 liters per second of desalinated water to Colina and Tiltil’s rural systems serves approximately 20,000 people—meeting the WHO’s 20-50 LPCD (liters per capita daily) basic survival threshold and moving families from water truck dependency to continuous access³.

Additional beneficiaries:

• 20,000 residents along the 100-kilometer pipeline route gain water security³
• Anglo American’s broader Rural Drinking Water Program has improved 83 systems across four provinces³
• Benefiting 130,000+ people with a 35% increase in water availability³

Indirect benefits: A watershed-scale transformation

The indirect benefits from freshwater cessation potentially dwarf direct provision.

Freeing 170-500 liters per second (14.7-43.2 million liters daily) in the Maipo and Aconcagua basins returns water to ecosystems and communities simultaneously³. Santiago’s six million residents depending on these glacial-fed rivers gain enhanced water security as mining demand drops.

Phase 2’s water swap amplifies impact exponentially: providing 500 l/s of desalinated water for human consumption while receiving treated wastewater for mining could secure drinking water for one million people before 2030³—lifting roughly 5% of Chile’s population above the social foundation threshold in a single industrial transaction.

Measurable health improvements

Health outcomes improve measurably with water access. The WHO calculates that 1.4 million deaths and 74 million DALYs are preventable annually through improved water, sanitation, and hygiene globally⁴.

For Los Bronces’ 20,000-40,000 direct beneficiaries, applying the WHO’s prevention rates suggests:

• Approximately 14-28 deaths averted yearly⁴
• 740-1,480 DALYs prevented⁴
• Diarrheal disease drops 34%⁴
• Respiratory infections decline 25-30% through improved hand hygiene⁴
• Economic gains total $8 for every dollar invested in water infrastructure⁴

Entering the safe and just space

The “safe and just space” concept makes the transformation visible.

Communities moved from below the social foundation to within the safe space:

Before: <20 LPCD, water truck dependency, >30 minutes collection time

After: 50-100 LPCD, on-premises or nearby access, <30 minutes, affordable at <3-5% of household income⁴

Simultaneously, basins moved away from the ecological ceiling as water stress declined below 100% and environmental flow requirements approached the 37% annual average and 60% low-flow targets⁴.

Los Bronces demonstrates that the “safe and just space” expands when industrial users exit freshwater entirely rather than merely improving efficiency.

Industry-wide momentum builds toward 2030 targets

Major mining companies set ambitious targets

Los Bronces sits within a broader sectoral transformation as water scarcity forces mining companies toward ambitious freshwater reduction commitments.

Key industry commitments:

• Anglo American: 50% reduction in water-scarce regions by 2030 (applies across 83% of operations globally)³²
• BHP: Achieved 17% reduction by 2020 (two years early), targets 50% of water needs from desalination by 2030²
• Codelco (Chile’s state-owned): 60% reduction in inland water consumption by 2030²
• Antofagasta Minerals: 66% desalination by 2031²
• SQM (lithium): 65% water use reduction by 2040, 50% brine extraction reduction by 2028²

Industry frameworks drive standardization

The International Council on Mining and Metals (ICMM), representing approximately one-third of the global industry, mandates water stewardship across member companies through its 2017 Position Statement and 2023 Maturity Framework².

Requirements include:

• Transparent reporting
• Catchment-level collaboration
• Efficiency improvements through recycling
• Context-based target setting aligned with local water stress levels²

Glencore implements approximately 49 site-level water targets at assets in water-stressed regions, while Newmont operates basin-wide integrated approaches². The framework represents a shift from volumetric targets alone to understanding catchment contexts, ecosystem needs, and community water security holistically.

Technology adoption accelerates unevenly

Chile leads desalination deployment with 12 operational plants and 15 planned, driving 230% growth in seawater use over the next decade⁶.

Proven technologies at scale:

• BHP’s Escondida: Operates entirely on desalinated seawater powered by 100% renewables²
• Tailings filtration: BHP and Rio Tinto collaborate on technology recovering up to 80% of process water²⁶
• Water recycling: Industry average of 75%, best-in-class at 85-90%⁶
• El Soldado facility: 80% tailings water recovery through hydraulic dewatering²⁶

Dry processing remains limited to specific ores. Vale processes 70% of iron ore production with minimal water through dry magnetic separation, but no commercial dry alternatives to flotation exist for most minerals⁶.

Barriers persist despite momentum

Permitting delays reach up to six years in Chile, strangling project timelines and creating regulatory uncertainty⁶.

Key challenges:

• High capital costs: $1-4 billion for major desalination projects⁶
• Energy costs: Represent 50-70% of operating expenses⁶
• Brine disposal: Lacks clear environmental standards in Chile, creating marine ecosystem risks⁶
• Social acceptance: Communities weigh desalination benefits against environmental impacts and trust deficits⁶

Yet the direction is unmistakable: by 2034, 66% of Chilean copper production will use seawater, fundamentally restructuring the industry’s relationship with freshwater¹.

Environmental restoration potential grows measurably

Quantifiable water returns to ecosystems

Ceasing freshwater withdrawals creates quantifiable environmental recovery opportunities.

Los Bronces frees 170-500 liters per second in the Maipo and Aconcagua basins—between 5.4 and 15.8 million cubic meters annually³. This volume represents movement toward the scientifically recommended 37% of mean renewable freshwater reserved for ecosystems, with critical seasonal protections of 60% during low-flow periods when aquatic life faces greatest stress⁴.

Chile’s Maipo basin, which reached Water Stress Index levels exceeding 100% during 2010-2020 (meaning withdrawals exceeded renewable resources), can begin recovering toward the <30% “environmentally safe” threshold¹.

Groundwater recovery: A multi-decade timeline

Groundwater restoration timelines extend over decades.

Central Chile’s aquifers, depleted by an 17.8-fold increase in withdrawals since 1970, face recovery periods of approximately 50 years even under best-case scenarios of reduced pumping and increased recharge¹.

The challenge is substantial:

• 50-meter water table declines over recent decades represent storage losses requiring sustained recharge to reverse¹
• Aquifer systems already overexploited by 65% beyond what drought alone explains¹
• Los Bronces’ cessation eliminates one industrial user from these stressed systems¹

While a single mine cannot restore regional groundwater, each withdrawal eliminated moves systems incrementally toward hydrological balance.

Ecosystem benefits beyond volume

Ecosystem benefits extend beyond volumetric flows.

25% of the world’s river basins currently dry up before reaching oceans due to excessive freshwater use⁴. Maintaining environmental flows sustains:

• Aquatic biodiversity
• Sediment transport
• Floodplain connectivity
• Estuarine salinity gradients essential for fisheries

The WHO identifies water-related ecosystems—rivers, wetlands, aquifers, glaciers—as degrading “unabated” globally despite SDG 6.6 targets to protect and restore them by 2020⁴.

Mining cessations in headwater regions like Los Bronces offer disproportionate downstream benefits as restored flows propagate through entire river systems to benefit hundreds of kilometers of aquatic habitat.

Protecting Chile’s disappearing glaciers

Glacier protection represents an urgent co-benefit.

Chilean glaciers have shrunk 98% this century, losing 8.54-15.14 gigatons—equivalent to 14 years of Chile’s total water needs¹.

Los Bronces operates near Olivares glaciers feeding the Maipo River, with mining dust darkening glacier surfaces, reducing albedo, and accelerating melting¹.

Ceasing local freshwater withdrawals reduces operational intensity near glacier zones while demonstrating industry recognition of glacial water’s irreplaceable value for 70% of Chile’s population depending on glacial-fed supplies¹.

Replicability depends on specific regional conditions

The critical variable: Coastal proximity

The Los Bronces model’s global applicability varies dramatically by geological, economic, and regulatory contexts.

16% of critical mineral mines globally already operate in high or extremely high water-stress areas, projected to reach 20% by 2050²—these represent prime candidates for freshwater cessation strategies.

Coastal proximity emerges as the critical variable:

• Desalination becomes economically viable within approximately 200 kilometers of ocean⁶
• Beyond this distance, pumping costs escalate ($1-4/m³ delivered vs. $0.50-2/m³ at plant)⁶
• Energy requirements (70% of pipeline operating costs) become prohibitive⁶

Ideal conditions: Chile, Peru, and coastal Australia

These regions present ideal conditions for replication:

• Arid climates
• Coastal mining concentrations
• Severe water stress
• High-value mineral deposits justifying capital investment
• Regulatory frameworks increasingly mandating seawater use⁶

Chile’s approach of nearly $17 billion cumulative investment through 2030 with shared infrastructure between mines demonstrates the economic scale required⁶.

Proven success stories: BHP’s Escondida and Spence mines both operate entirely on desalinated seawater, with Escondida running on 100% renewable power since 2022—proving technical and economic feasibility at world-class operations².

Inland alternatives: Water recycling strategies

South Africa’s platinum mines illustrate alternative approaches for inland operations where desalination is impractical.

Water recycling in the platinum sector increased from 30% to 60% over the past decade, with leading operations achieving 85-90% reuse through:

• Thickeners
• Filter presses
• Closed-loop concentrator circuits²⁶

Anglo American’s El Soldado facility recovers 80% of tailings water through hydraulic dewatering, while BHP and Rio Tinto’s collaboration on large-volume filter technology removes 80% of water from tailings for reuse²⁶.

These recycling approaches apply universally but cannot eliminate freshwater intake entirely due to evaporation, brine concentration, and process losses.

Dry processing: Limited but promising

Dry processing remains highly ore-specific.

Vale’s success: Processes 70% of iron ore production through dry methods in Brazil’s Carajás mines where ore grades exceed 65% iron, requiring only crushing and screening⁶.

Rio Tinto’s Iron Bridge project in Australia employs dry magnetic separation achieving:

• 30% energy reduction
• 43% emissions cuts⁶

However, no commercial dry alternatives to flotation exist for copper, gold, or most other minerals, limiting widespread applicability⁶. The technology’s long-term potential is substantial, but near-term replication remains confined to specific high-grade iron ore and coal applications.

Economic barriers fall as water scarcity rises

The shifting cost equation

The cost equation for freshwater cessation has shifted fundamentally as water scarcity intensifies.

Desalination at $0.50-2.00/m³ at the plant and $1.00-4.00/m³ delivered remains 10 times more expensive than groundwater at baseline⁶.

Yet operational disruptions from water shortages now exceed these premiums:

• Los Bronces’ 44% throughput reduction in 2023 due to water constraints¹
• Water costs reaching $5/m³ for remote mines competing with communities⁶

BHP’s $4 billion investment in Escondida’s desalination over 15 years reflects calculations that water security justifies premium costs when alternatives include production losses and social license failures².

Capital requirements and shared infrastructure

Capital requirements remain substantial:

• Los Bronces’ $1.65 billion for Phase 1 (desalination plant and pipeline infrastructure)³
• Chilean mining’s collective $17 billion through 2030⁶

Shared infrastructure reduces individual mine costs: multiple operations can contract capacity from single desalination plants, spreading CAPEX across users and improving project economics⁶.

Modular containerized systems offer lower-cost alternatives for smaller operations, with construction timelines of months rather than 2-3 years required for traditional plants⁶.

Energy economics: The dominant factor

Energy represents 50% of total desalination costs, with pipeline pumping consuming 70% of transportation expenses⁶.

Modern efficiency gains:

• 1970s: 20-30 kWh/m³
• Modern reverse osmosis: 3.0-5.5 kWh/m³
• Theoretical minimum: 1 kWh/m³⁶

Renewable energy integration transforms the equation: BHP’s Escondida desalination runs on 100% renewable power, eliminating fossil fuel price volatility and reducing carbon footprints². Chile’s abundant solar resources in the Atacama Desert offer competitive renewable electricity that continuously lowers desalination operating costs.

Water recycling: Immediate returns at lower cost

Treatment for recycling runs $0.21-1.00/m³—far below desalination—with industry achieving 75% average recycling rates and best performers at 85-90%⁶.

Key metrics:

• Anglo American reports 66% of total water needs through closed-loop systems while targeting higher rates²
• Filter press systems cost one-sixth of belt presses or centrifuges to operate while recovering up to 90% of process water⁶
• The WHO calculates $8 return for every $1 invested in water and sanitation infrastructure⁴

Recycling cannot eliminate freshwater intake entirely but maximizes efficiency at costs accessible to all mines regardless of coastal proximity.

Governance gaps slow implementation despite urgency

Regulatory barriers: The primary constraint

Regulatory barriers emerge as the primary constraint on freshwater cessation despite technical feasibility and economic drivers.

Chile’s permitting processes extend up to six years for major water infrastructure projects—a timeline that discourages investment and delays environmental benefits⁶.

Key regulatory challenges:

• Regulatory uncertainty around mandatory seawater use, brine disposal standards, and environmental discharge limits⁶
• Investment risks that inflate capital costs and defer project approvals⁶
• Mining Code amendments (Bulletin 9.185-08) remain pending, leaving ambiguity around future freshwater access⁶

Chile’s 2022 Water Code reform

The reform addresses structural issues but implementation lags.

Key provisions:

• Declares water a “national asset for public use” rather than private property¹
• Recognizes the human right to water and sanitation¹
• Converts water rights from perpetual ownership to 30-year renewable concessions¹
• Concessions can be revoked for non-use or unsustainability¹
• Prohibits new water rights in glaciers, protected areas, and northern wetlands¹
• Empowers water authorities to reduce underground extractions threatening aquifer sustainability¹

Yet enforcement capacity remains limited, and reconciling existing rights with new frameworks creates transition complexity¹.

Industry self-regulation through ICMM

The ICMM’s Water Stewardship Framework offers industry self-regulation where government mandates lag.

Requirements include:

• Proactive stakeholder engagement
• Transparent reporting of water use and risks
• Catchment-level collaboration to mitigate shared water challenges
• Increasing water use efficiency through recycling and reuse²

The 2023 Water Stewardship Maturity Framework provides self-assessment tools across five elements:

1. Governance/strategy
2. Context/risk understanding
3. Business planning integration
4. Performance measurement
5. Transparency/reporting

Three progressive stages: basic, advanced, leading²

Approximately one-third of global mining falls under ICMM member commitments, creating industry norms that shape expectations even for non-members².

Social license challenges

Community trust deficits in water management stem from historical extraction patterns where 90% of Chile’s freshwater came under private control following the 1981 Water Code¹.

Key challenges:

• Indigenous communities—particularly Chile’s Lickanantay—face disproportionate impacts from lithium and copper extraction in ancestral territories⁶
• Stakeholder disagreement on desalination environmental impacts, particularly brine disposal’s marine ecosystem effects⁶
• Opposition even to projects reducing freshwater competition⁶

Emerging best practice: Anglo American’s approach of dedicating 25% of desalinated water to communities and implementing transparent monitoring³.

The path to regenerative mining practices

The “waterless mine” concept

Los Bronces illuminates principles for mining that operates within planetary boundaries while supporting social foundations.

The “waterless mine” concept—eliminating freshwater from industrial processes entirely—becomes technically and economically achievable for coastal operations in water-stressed regions through desalination powered by renewables³².

Phase 2’s water swap innovation takes the model further: industry provides desalinated water for human consumption and receives treated wastewater, converting mining from water competitor to water provider while securing supply and social license simultaneously³.

Shared infrastructure: Lower costs, faster deployment

Chile’s approach of 12 operational and 15 planned large-scale desalination plants serving multiple mining operations distributes CAPEX while building collective capacity⁶.

BHP, Codelco, and Antofagasta Minerals all pursue shared desalination facilities rather than duplicative single-mine plants².

Co-benefits: Pipeline networks delivering water along routes enable rural communities to access supplies, generating social co-benefits that strengthen project approvals and community support³.

The model suggests that industry consortia, potentially with government co-investment, can build regional water infrastructure more efficiently than individual operations.

Critical technology integration

Los Bronces combines 90-94% water recycling with desalination rather than treating them as alternatives³⁵.

The integrated approach:

• Maximize recycling first: Minimizes desalinated volumes required, lowering costs and energy consumption
• Renewable energy integration: Following BHP Escondida’s 100% renewable desalination model²
• Tailings water recovery: Hydraulic dewatering, filter presses, and closed-loop concentrator circuits extract maximum value from each liter²⁶
• Reduce environmental risks: Less wet tailings storage²⁶

Catchment-level collaboration is essential

The ICMM framework’s emphasis on understanding all water users’ needs, engaging stakeholders proactively, and collaborating to mitigate shared water risks recognizes that mine-level efficiency gains prove insufficient when basins exceed sustainable withdrawal rates².

Los Bronces’ commitment within the UN SDG partnership framework to eliminate withdrawals entirely by 2030 represents catchment-scale thinking: recognizing that Santiago’s six million residents, downstream agriculture, and aquatic ecosystems all depend on the same Maipo and Aconcagua basins³⁷.

Industry water cessations must align with:

• Regional water management plans
• Environmental flow requirements (37% of renewable freshwater for ecosystems annually, 60% during low-flow periods)⁴
• Community water security targets (50-100 LPCD safely managed access)⁴

Conclusion

A proven model for mining within planetary boundaries

Los Bronces’ transformation from water competitor to potential water provider demonstrates that mining within planetary boundaries while meeting social foundations is technically feasible, economically viable under water scarcity conditions, and replicable in specific regional contexts.

The commitment to eliminate 14.7-43.2 million liters of daily freshwater withdrawals by 2030, combined with the potential to provide drinking water security for one million people through innovative water swaps, illustrates the “safe and just space” concept in practice.

Simultaneously achieved:

• Moving communities above the social foundation (50-100 LPCD safely managed water access)
• Moving river basins below the ecological ceiling (water stress <25%, environmental flows >37% annually)

Global applicability and industry momentum

The model’s applicability extends to the 16% of critical mineral mines in water-stressed areas globally, particularly coastal operations within 200 kilometers of oceans in arid regions like Chile, Peru, and Australia where desalination economics prove favorable.

Industry-wide momentum toward 2030 freshwater reduction targets signals sectoral recognition that water scarcity now constrains production more than ore grades or metal prices:

• Anglo American: 50% cut
• BHP: 50% desalination
• Codelco: 60% reduction

Three critical gaps to address

Regulatory barriers: Six-year permitting delays

Energy costs: 50% of desalination expenses

Social license: Requiring transparent governance and equitable benefit-sharing

The potential impact

Addressing these gaps through streamlined approvals, renewable energy integration, and community water provision models can unlock:

• $17 billion in Chilean mining desalination investment
• Health benefits: 1.4 million preventable deaths globally from improved water access
• Ecosystem restoration: Returning flows toward 37% environmental allocation
• Economic returns: $8 per dollar invested in water infrastructure

A pathway to regenerative mining

Los Bronces offers a replicable pathway where industrial water cessation in stressed regions simultaneously restores ecosystems and enhances community resilience—regenerative mining that respects planetary boundaries while meeting human needs within the safe and just space between social foundations and ecological ceilings.

References