Water Footprint
Definition
Water footprint
A water footprint refers to the total volume of freshwater used to produce goods and services consumed by an individual, community, or nation.
- A water footprint quantifies the amount of water consumed, polluted, or evaporated during the production or use of goods and services.
- It helps identify where water use is unsustainable, and informs decision-making for water management and policy.
- The footprint can be applied to individuals, industries, products, or countries to understand consumption impacts.
Introduced in 2002, the concept shifted attention from production-based to consumption-based water use, helping track the hidden water flows in global trade.
Components of the Water Footprint
1. Blue Water Footprint
- Water drawn from surface and groundwater sources (rivers, lakes, aquifers).
- Used for irrigation, industry, and domestic supply.
2. Green Water Footprint
- Rainwater absorbed by plants and stored in soil.
- Vital for agriculture and natural vegetation.
3. Grey Water Footprint
- Volume of water required to dilute pollutants and maintain acceptable water quality standards.
- Includes wastewater from households, agriculture, and industry.
- The global average water footprint per person is about 1,385 m³ per year, but this varies widely:
- USA: ~2,842 m³/person/year (due to high meat and industrial consumption).
- India: ~1,089 m³/person/year (due to large population and agriculture).
Blue = extraction, Green = rainfall absorption, Grey = pollution load.
Internal vs. External Water Footprints
- Internal Water Footprint: Water used within a country to produce goods consumed domestically.
- External Water Footprint: Water used in other countries to produce imported goods and services.
The UK’s external water footprint is large because it imports water-intensive goods like cotton, beef, and coffee produced elsewhere.
Global Patterns in Water Footprints
- The average global water footprint per person is about 1,385 m³/year.
- India has the largest total footprint (987 billion m³/year), while the USA has the highest per capita footprint (≈ 2,842 m³/person/year).
- Water footprints vary by:
- Dietary habits: Meat-based diets use more water than plant-based ones.
- Climate: Dry regions require more irrigation.
- Economic development: Industrialized nations use more “virtual water” through imports and manufacturing.
Producing 1 kg of beef requires over 15,000 liters of water, while 1 kg of potatoes needs only 287 liters. Shifting diets can drastically reduce national water footprints.
Analogy- A country’s water footprint is like its “hydrological signature".
- It shows how much water is used locally and imported through trade.
