Freshwater Use (Planetary Boundary)

Freshwater availability is fundamental to human civilization and ecosystem health. While global freshwater use remains below planetary boundaries at the aggregate level, regional water stress is severe in many areas, affecting over 2 billion people. The planetary boundary framework distinguishes between "blue water" (surface and groundwater) and "green water" (soil moisture from precipitation), with blue water consumption being the primary control variable.

Understanding the Freshwater Boundary

The planetary boundary for freshwater use is set at 4,000 km³/year of blue water consumption globally, with current use estimated at approximately 2,600 km³/year. However, this global figure masks critical regional variations. The boundary has been transgressed in several major river basins, including the Indus, Ganges, Yellow River, and Murray-Darling, where water withdrawals exceed sustainable limits.

Blue Water vs. Green Water:

• Blue water: Liquid water in rivers, lakes, reservoirs, and aquifers that can be withdrawn for human use
• Green water: Soil moisture from precipitation that supports rainfed agriculture and natural ecosystems

The distinction matters because blue water withdrawal can directly impact river flows, groundwater levels, and aquatic ecosystems, while green water use (primarily rainfed agriculture) has different environmental implications.

Why Freshwater Matters for ESG

Water scarcity poses significant risks to business operations, supply chains, and communities. Industries such as agriculture (70% of global water use), energy (15%), and manufacturing (12%) are particularly water-intensive. Companies face multiple water-related risks:

Physical Risks: Water scarcity limiting operations, droughts affecting supply chains, flooding damaging facilities

Regulatory Risks: Water allocation restrictions, discharge limits, pricing increases, license revocations

Reputational Risks: Community conflicts over water access, negative media coverage, investor scrutiny

Financial Risks: Increased operating costs, stranded assets in water-scarce regions, reduced access to capital

The CDP Water Security questionnaire has become a standard for corporate water disclosure, with over 4,000 companies reporting annually on water risks, management strategies, and performance.

Key Metrics & KPIs for Companies

Water Quantity Metrics

• Total water withdrawal (megaliters): By source (surface, ground, sea, third-party)
• Water withdrawal in water-stressed areas (megaliters or %): Using WRI Aqueduct or similar tools
• Water consumption (megaliters): Withdrawal minus discharge (water not returned to source)
• Water intensity (m³ per unit): Per revenue, per product, or per employee
• Water recycling rate (%): Volume recycled/reused as percentage of total withdrawal

Water Risk Metrics

• Facilities in water-stressed areas (number or %): Based on standardized risk assessment
• Water-related operational disruptions: Number and duration of incidents
• Groundwater depletion risk: Facilities relying on overexploited aquifers
• Flood exposure: Assets in high-risk flood zones

Water Quality Metrics

• Effluent discharge volume (megaliters): By destination and quality
• Pollutant concentrations: BOD, COD, TSS, heavy metals, nutrients
• Compliance rate (%): Percentage of discharge permits in compliance
• Ecosystem health: Monitoring of receiving water body conditions

Water Governance Metrics

• Water management plan: Presence and scope of formal water strategy
• Water-related capital expenditure: Investments in efficiency and treatment
• Stakeholder engagement: Participation in watershed initiatives
• Water-related targets: Commitments to reduce use or improve efficiency

WRI Aqueduct Water Risk Atlas

The World Resources Institute's Aqueduct tool is the leading platform for assessing water risks globally. Aqueduct 4.0 (released 2023) evaluates water risk across 13 indicators grouped into three categories:

Physical Risk Quantity (8 indicators):

1. Baseline water stress
2. Interannual variability
3. Seasonal variability
4. Groundwater table decline
5. Riverine flood risk
6. Coastal flood risk
7. Drought risk
8. Water depletion

Physical Risk Quality (2 indicators): 9. Untreated connected wastewater 10. Coastal eutrophication potential

Regulatory & Reputational Risk (3 indicators): 11. Unimproved/no drinking water 12. Unimproved/no sanitation 13. Peak RepRisk ESG risk index

Companies can use Aqueduct to identify high-risk facilities, prioritize water stewardship investments, and report water risks to investors and stakeholders.

Corporate Water Stewardship

Effective water stewardship goes beyond operational efficiency to encompass watershed-level collaboration and community engagement. The Alliance for Water Stewardship (AWS) Standard provides a comprehensive framework across five steps:

1. Gather & Understand: Assess water context and stakeholder perspectives
2. Commit & Plan: Develop water stewardship plan with targets
3. Implement: Execute actions to improve water management
4. Evaluate: Monitor performance and adapt strategies
5. Communicate & Disclose: Share progress transparently

AWS certification demonstrates credible commitment to responsible water use and has been adopted by major companies including Diageo, Olam, and Nestlé.

Regional Water Challenges

Middle East & North Africa

The MENA region faces the world's most severe water scarcity, with 17 countries experiencing extremely high baseline water stress. Groundwater depletion, population growth, and climate change are exacerbating challenges.

South Asia

The Indus and Ganges basins support over 1 billion people but face severe overextraction. Groundwater depletion in India and Pakistan threatens agricultural productivity and food security.

Western United States

The Colorado River basin, supporting 40 million people and 5.5 million acres of agriculture, has experienced 23 years of drought, with reservoir levels at historic lows.

China

Northern China faces severe water scarcity, with per capita water availability one-quarter of the global average. The South-to-North Water Diversion Project transfers water from the Yangtze to northern regions.

Related Pages

• Environmental Hub
• Water Resources & Stewardship — Corporate water management
• Climate Change — Impacts on water cycle
• GRI 303 — Water disclosure standard
• SDG 6: Clean Water and Sanitation