Why Water Use in Agriculture is a Critical Business Risk
Water use in agriculture accounts for approximately 70% of global freshwater usage, making it the largest consumer of water resources worldwide. As climate change intensifies droughts, floods and rainfall variability, water availability is becoming increasingly unpredictable, and directly impacting global food systems and agricultural supply chains.
For businesses, agricultural water use is no longer just an environmental concern. It is a supply chain risk, financial risk and regulatory compliance issue.
Water scarcity, pollution and regional water stress are now key considerations in frameworks such as CDP Water Disclosure, GRI Standards, TNFD and ISO 14046 Water Footprint Assessment. All of which require organisations to better understand and manage water dependencies across their value chains.
Global Agricultural Water Use and Water Stress Hotspots
Agricultural water consumption varies significantly across regions due to climate conditions, infrastructure and economic development.
In many parts of Africa and Asia, agriculture accounts for more than 80% of total freshwater withdrawals, driven by irrigation dependence and water scarcity. In contrast, Western Europe uses significantly less freshwater for agriculture, often around 5% of total withdrawals, due to more efficient systems and differing agricultural structures.
For organisations sourcing agricultural commodities globally, this creates uneven exposure to:
- drought risk in arid regions
- irrigation dependency in water-stressed basins
- regulatory restrictions on abstraction
- long-term resource scarcity
Source: Food and Agriculture Organization of the United Nations
How is Water Used Across Agricultural Supply Chains
Water use in agriculture extends far beyond irrigation. It is embedded across the entire food production lifecycle, creating both direct and indirect water impacts.
1. Irrigation of crops:
This is the most common and water-intensive process in agriculture. It includes surface irrigation (flooding), sprinkler systems and more efficient methods like drip irrigation. The type of irrigation used greatly impacts water consumption and efficiency.
2. Livestock drinking water and cleaning:
Water is required to keep animals hydrated, clean and healthy. Facilities that raise animals for meat, dairy or eggs must maintain hygiene through frequent washing and sanitation, all of which consume substantial amounts of water.
3. Post-harvest processing:
Once crops are harvested, water is often used to wash, sort and package produce. This step is essential for food safety and shelf life but can be water-intensive without efficient systems in place.
4. Cooling and climate control in greenhouses:
In controlled environments like greenhouses, water is also used to cool the environment and maintain optimal humidity levels. Evaporative cooling systems, for instance, are major contributors to water use.
5. Pesticide and fertiliser application:
Water is often used as a carrier for agrochemicals, ensuring even distribution across fields. This practice, however, contributes to runoff and increases the grey water footprint due to contamination.
Types of Water in Agriculture (ISO 14046 Framework)
Water footprinting categorises agricultural water use into three key components under internationally recognised methodologies such as ISO 14046. These categories make it easier to track different water sources and their effects on the environment. Farmers and policymakers can use this knowledge to create better water management strategies that work in different climate conditions.
Green Water (rainwater stored in soil)
Green water refers to rainfall that infiltrates the soil and is used directly by plants through evapotranspiration. It accounts for approximately 78% of the global crop water footprint and is critical for rain-fed agriculture.
Because if does not involve abstraction from freshwater sources, green water is generally considered the most sustainable form of agricultural water use. However, it is highly sensitive to:
- land use change
- deforestation
- climate variability
Blue Water (surface and groundwater)
Blue water is freshwater sourced from surface bodies such as rivers and lakes, or groundwater such as aquifers, used for irrigation or livestock. Blue water is typically accessed through irrigation systems, wells, canals and reservoirs. It supports intensive agriculture, particularly in arid and semi-arid zones where rainfall is insufficient. The rapid growth of irrigated farming puts huge pressure on the environment, and groundwater pumping for irrigation now leads all other groundwater uses globally. Overuse of blue water can lead to aquifer depletion, reduced river flows and cause ecological degradation. Sustainable use requires monitoring withdrawal rates against recharge capacities.
Grey Water (pollution impact)
Grey water in farming refers to freshwater that gets polluted by agricultural activities. It refers to the volume of freshwater required to dilute pollutants (e.g. nitrates, phosphates) to meet water quality standards. Grey water is a metric of the environmental impact of farming practices on water quality. High grey water volumes indicate inefficient input use and pollution. Managing grey water is essential for protecting downstream water bodies. Strategies such as precision fertilisation and constructed wetlands can help reduce this footprint. Grey water can also be sent to water treatment facilities for purification.
Bertie Bott's Every Flavour Water: Understanding Water Footprinting
In this whitepaper written by Dr Gareth Davies, Senior Scientist and Carbon Co-Lead at Tunley Environmental, he discusses Water Footprint Assessments in details to help you gain a good understanding of them.
We are going to explain simply; the common terminology used in water footprinting assessments. When it comes down to it, we need water to live. It is a simple as that. Water footprinting assessments enable us to make sure that there is enough water for us in the future. By understanding these common terminologies, you shall be able to take actionable steps towards preserving that future.
Water Footprint Assessment in Agriculture
A Water Footprint Assessment (WFA) is a scientifically grounded method of evaluating the volume and impact of water used across agricultural supply chains. It helps companies in measuring and managing their water footprint inline with the international water footprinting standard ISO 14046.
The assessment considers:
Direct water use:
This includes all on-farm water uses, such as irrigation, animal care, and processing. It helps quantify operational efficiency and reveals opportunities for saving water.
Indirect water use:
Refers to water embedded in inputs like feed, seeds, fertilisers and pesticides. Understanding this "virtual water" footprint is essential for full supply chain transparency.
Water pollution and waste discharge:
The assessment calculates how much water is required to assimilate pollutants, providing insight into environmental degradation and compliance risks.
Water footprint assessments help businesses:
Identify hotspots of water overuse:
Pinpointing where in the production cycle water demand is highest allows for targeted interventions.
Understand dependencies on water-stressed regions:
Mapping water use against geographical risk helps businesses manage exposure to droughts, regulation and supply chain disruption.
Improve resource efficiency:
By optimising irrigation and input application, farms can reduce waste, costs and their environmental footprint.
Enhance supply chain sustainability:
Demonstrating responsible water use supports customer expectations and retailer procurement policies.
Support regulatory compliance:
Standards like ISO 14046 and frameworks like the Science Based Targets for Nature increasingly require robust water accounting.
The Importance of Monitoring Water Use in Agriculture
Improving water efficiency is a strategic business move for sustainability in the agricultural sector. Key benefits include:
Enhanced resilience to climate variability: Better planning in water use makes operations more adaptable to extreme weather events.
Improved stakeholder and investor confidence: Transparent water reporting demonstrates proactive ESG management, attracting values-driven partners.
Compliance with sustainability frameworks: Aligning with initiatives like CDP Water, GRI Standards and the UN SDGs supports procurement requirements and brand reputation.
Support for ESG and Net Zero targets: Water efficiency often correlates with energy savings, helping to meet broader climate goals.
Tunley Environmental Water Footprint Assessment Services
Tunley Environmental supports organisations in understanding and managing water-related risks across agricultural and supply chains through ISO 14046-aligned assessments with a Water Footprint Assessment (WFA).
Our services include:
- Measurement of the total water footprint of company, product or process
- Identifying opportunities to mitigate water usage, consumption and withdrawal as well as minimise wastewater through:
- process optimisation
- water recycling & reuse
- leak detection & prevention
- equipment & technology upgrades
- water catchment
- Water usage analysis which will
- quantify and analyse water consumption and water withdrawal drivers
- provide detailed insights into water usage volumes
Building Water Resilience in Agriculture
Agricultural water use is under increasing pressure from climate change, population growth and environmental degradation. Understanding how water is used and where the greatest risks lie is essential for building resilient, future-proof supply chains.
Organisations that measure and manage water footprints today will be better positioned to; reduce operational risk, meet regulatory requirements, improve sustainability performance and strengthen long-term resilience. Water footprinting is no longer optional, it is a core component of modern environmental and supply chain strategy.