GRI 303 Water & Effluents
GRI 303 covers water withdrawal, consumption, and discharge — the foundational water disclosure in the GRI framework. For water-intensive industries, water risk is increasingly material. The 2018 update significantly expanded requirements beyond simple withdrawal volumes.
GRI 303 covers water withdrawal, consumption, and discharge — the foundational water disclosure in the GRI framework. The 2018 GRI 303 revision was a substantial overhaul.
What the 2018 revision added
The 2018 GRI 303 revision was a substantial overhaul. Key additions: water stress context (data must now be broken down by whether sources are in water-stressed areas); distinction between withdrawal and consumption (consumption = withdrawal minus discharge); and effluent quality disclosure.
303-1 Interactions with water as a shared resource: Qualitative description of how the organisation interacts with water — dependencies, impacts, and how the business model affects water availability.
303-2 Management of water discharge-related impacts: Approach to preventing and mitigating significant discharges.
303-3 Water withdrawal: Total by source (surface water, groundwater, seawater, produced water, third-party water), broken down by water-stressed and non-stressed areas.
303-4 Water discharge: Total by destination and quality.
303-5 Water consumption: Withdrawal minus discharge — the net water used.
Identifying water-stressed areas
GRI 303 requires data split by water-stressed areas. The standard tool for this is the WRI Aqueduct Water Risk Atlas — a free online tool that maps baseline water stress, drought risk, and groundwater depletion by location.
For each of your operational sites, run the location through Aqueduct. Sites in 'High' or 'Extremely High' baseline water stress require separate disclosure of withdrawal and consumption volumes.
For ESRS E3 (CSRD), the same geographic screening is required. Running the Aqueduct screening once satisfies both GRI 303 and ESRS E3 location requirements.
Water consumption vs withdrawal — why it matters
Water withdrawal is the total water taken from any source. Water consumption is the portion that is not returned to the source — it is evaporated, incorporated into products, or discharged to a different catchment.
For most office-based businesses, consumption equals withdrawal (water goes to sewerage and is treated, not returned to the original source). For manufacturing with cooling water returned to rivers, consumption can be a fraction of withdrawal.
Investors and water risk frameworks focus on consumption — it is the metric that represents the actual depletion of water resources in a catchment.
Frequently asked questions
Do we need to report GRI 303 if we only use municipal water?
Yes — municipal (third-party) water is a withdrawal source under 303-3. You must still report volumes and disclose whether the municipal source is in a water-stressed area. Many municipal supplies draw from water-stressed catchments.
What is the unit for GRI 303 water disclosures?
Megalitres (ML) or cubic metres (m³). Both are acceptable — declare your unit and use it consistently. 1 ML = 1,000 m³.
Is GRI 303 applicable to office-only businesses?
GRI 303 applies but typically results in low materiality for pure office businesses. Water consumption from office sanitation, catering and cooling towers is usually immaterial relative to business impacts. A brief explanation of low materiality is sufficient.