GRI 303: Water and Effluents·Disclosure GRI 303-4
Water discharge
Practical guidance for preparing this disclosure. Use this card to identify the information to prepare, verify claims and organise supporting evidence. For exact requirements, always refer to the official Global Reporting Initiative source.
Legal status
GRI 303: Water and Effluents 2018 remains the applicable GRI Topic Standard for water-related reporting and is effective for reports or other materials published on or after 1 January 2021.
Published passport
Last reviewed 2026-08-01
Reviewed by
Dr Ross KurinkoLinkedIn
Strategic ESG Advisor · IFRS S1 & S2 / GRI / ESRS expert
GRI Certified Global Trainer · PhD, University of Cambridge · ESG-AI expert
15+ years on FTSE 100 & Fortune Global 500 disclosures
Canary Wharf, London
LRA educational guidance · Not issued or endorsed by Global Reporting Initiative
Standard
GRI 303: Water and Effluents
Disclosure GRI 303-4 · 2018
Last reviewed
2026-08-01
LRA educational guidance · Not issued or endorsed by Global Reporting Initiative
Disclosure focus
Disclosure 303-4 requires an organization to report total water discharge to all areas in megaliters and break this total down by destination: surface water, groundwater, seawater and third-party water. Where any third-party water is sent to other organizations for use, that volume is included in total third-party water and reported separately as a subset.
The organization also reports total water discharge by water quality. For all areas and for all areas with water stress, it reports freshwater, defined as water with total dissolved solids of 1 000 mg/L or less, and other water, defined as water with total dissolved solids above 1 000 mg/L.
Areas with water stress are identified using publicly available and credible tools or methodologies. The organization explains the tool, geographic resolution, threshold, assessment date and assumptions used.
The organization reports the priority substances of concern for which discharges are treated, explains how those substances were defined and identifies any international standard, authoritative list or criteria used. It also explains how discharge limits were set and reports the number of incidents of non-compliance with those limits.
The number of incidents of non-compliance is distinct from the recommended number of occasions on which limits were exceeded. Where both are reported, the counting methodologies should be explained.
GRI additionally recommends reporting discharge by level of treatment and the percentage of suppliers with significant water-discharge impacts that have established minimum effluent-quality standards beyond regulatory requirements.
This LRA educational guidance supports disclosure preparation. For the exact requirements, always refer to the official Global Reporting Initiative source.
Before you start
Before you start
A quick mental checklist before you prepare this disclosure — tick each as you settle it.
Preparation
Key information to prepare
| Preparation field | What to capture | Evidence hint | Owner |
|---|---|---|---|
| Reporting period | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting reporting period. | Sustainability Reporting / data owner |
| Organizational scope | Required contextual information. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting organizational scope. | Sustainability Reporting / data owner |
| Total discharge in ML | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting total discharge in ml. | Environment / Water / Sustainability Reporting |
| Surface-water discharge | Required where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting surface-water discharge. | Environment / Water / Sustainability Reporting |
| Groundwater discharge | Required where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting groundwater discharge. | Environment / Water / Sustainability Reporting |
| Seawater discharge | Required where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting seawater discharge. | Environment / Water / Sustainability Reporting |
| Third-party water discharge | Required where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting third-party water discharge. | Environment / Water / Sustainability Reporting |
| Municipal sewer mapped to third-party water | Required methodological control. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting municipal sewer mapped to third-party water. | Environment / Water / Sustainability Reporting |
| Third-party water sent for use | Required where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting third-party water sent for use. | Environment / Water / Sustainability Reporting |
| Reuse volume treated as subset | Required control. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting reuse volume treated as subset. | Sustainability Reporting / data owner |
| Freshwater ≤1 000 mg/L TDS — all areas | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting freshwater ≤1 000 mg/l tds — all areas. | Environment / Water / Sustainability Reporting |
| Other water >1 000 mg/L TDS — all areas | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting other water >1 000 mg/l tds — all areas. | Environment / Water / Sustainability Reporting |
| Total discharge in stressed areas | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting total discharge in stressed areas. | Environment / Water / Sustainability Reporting |
| Freshwater — stressed areas | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting freshwater — stressed areas. | Environment / Water / Sustainability Reporting |
| Other water — stressed areas | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting other water — stressed areas. | Environment / Water / Sustainability Reporting |
| Credible public water-stress methodology | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting credible public water-stress methodology. | Environment / Water / Sustainability Reporting |
| Catchment-level assessment | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting catchment-level assessment. | Environment / Water / Sustainability Reporting |
| Priority substances treated | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting priority substances treated. | Sustainability Reporting / data owner |
| Definition criteria | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting definition criteria. | Sustainability Reporting / data owner |
| International standard or authoritative list | Required where used. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting international standard or authoritative list. | Sustainability Reporting / data owner |
| Limit-setting approach | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting limit-setting approach. | Sustainability Reporting / data owner |
| Incidents of non-compliance | Required. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting incidents of non-compliance. | Legal / Compliance / Sustainability Reporting |
| Occasions of exceedance | Recommended. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting occasions of exceedance. | Sustainability Reporting / data owner |
| Treatment-level breakdown | Recommended. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting treatment-level breakdown. | Sustainability Reporting / data owner |
| Basis for treatment levels | Recommended. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting basis for treatment levels. | Sustainability Reporting / data owner |
| Supplier minimum-standard percentage | Recommended. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting supplier minimum-standard percentage. | Procurement / Finance / Sustainability Reporting |
| Measured and estimated data separated | Required where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting measured and estimated data separated. | Sustainability Reporting / data owner |
| Destination reconciliation | Required assurance control. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting destination reconciliation. | Sustainability Reporting / data owner |
| TDS reconciliation | Required assurance control. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting tds reconciliation. | Sustainability Reporting / data owner |
| Stressed-area subset reconciliation | Required assurance control. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting stressed-area subset reconciliation. | Sustainability Reporting / data owner |
| Link to GRI 3-3 | Required contextual control. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting link to gri 3-3. | Sustainability Reporting / data owner |
| Links to GRI 303-1, 303-2, 303-3 and 303-5 | Necessary for consistency. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting links to gri 303-1, 303-2, 303-3 and 303-5. | Sustainability Reporting / data owner |
| Reason for omission | Required in GRI content index where applicable. Capture and reconcile this item using the scope, defined terms and calculation basis in the reviewed Disclosure focus. | Approved source records, calculation files, reconciliations and review evidence supporting reason for omission. | Sustainability Reporting / data owner |
How to prepare it
Request the data
Request the disclosure evidence
Translate the disclosure into an internal business question — then adapt it to your organisation's own language.
Provide the reporting-period records and reconciliations for Disclosure 303-4: Reporting period; Organizational scope; Total discharge in ML; Surface-water discharge; Groundwater discharge; Seawater discharge; Third-party water discharge; Municipal sewer mapped to third-party water; Third-party water sent for use; Reuse volume treated as subset; Freshwater ≤1 000 mg/L TDS — all areas; Other water >1 000 mg/L TDS — all areas; Total discharge in stressed areas; Freshwater — stressed areas; Other water — stressed areas; Credible public water-stress methodology; Catchment-level assessment; Priority substances treated; Definition criteria; International standard or authoritative list; Limit-setting approach; Incidents of non-compliance; Occasions of exceedance; Treatment-level breakdown; Basis for treatment levels; Supplier minimum-standard percentage; Measured and estimated data separated; Destination reconciliation; TDS reconciliation; Stressed-area subset reconciliation; Link to GRI 3-3; Links to GRI 303-1, 303-2, 303-3 and 303-5; Reason for omission. Include scope, definitions, methods, assumptions, limitations, owners and approvals.
Use the organisation's own role and document names, but preserve the defined GRI terms and the scope described above.
Better request
Provide the reporting-period records and reconciliations for Disclosure 303-4: Reporting period; Organizational scope; Total discharge in ML; Surface-water discharge; Groundwater discharge; Seawater discharge; Third-party water discharge; Municipal sewer mapped to third-party water; Third-party water sent for use; Reuse volume treated as subset; Freshwater ≤1 000 mg/L TDS — all areas; Other water >1 000 mg/L TDS — all areas; Total discharge in stressed areas; Freshwater — stressed areas; Other water — stressed areas; Credible public water-stress methodology; Catchment-level assessment; Priority substances treated; Definition criteria; International standard or authoritative list; Limit-setting approach; Incidents of non-compliance; Occasions of exceedance; Treatment-level breakdown; Basis for treatment levels; Supplier minimum-standard percentage; Measured and estimated data separated; Destination reconciliation; TDS reconciliation; Stressed-area subset reconciliation; Link to GRI 3-3; Links to GRI 303-1, 303-2, 303-3 and 303-5; Reason for omission. Include scope, definitions, methods, assumptions, limitations, owners and approvals.
Draft your disclosure
Notes that turn data into a disclosure
LRA training templates — adapt them to your organisation, and check the official source before sign-off.
Method note
GRI additionally recommends reporting discharge by level of treatment and the percentage of suppliers with significant water-discharge impacts that have established minimum effluent-quality standards beyond regulatory requirements.
Context note
Keep mandatory Requirements, GRI recommendations and additional LRA preparation controls clearly distinguished. Use a GRI 1 reason for omission where an applicable requirement cannot be reported.
Download Centre
Preparation tools & forms
Professional preparation tools for GRI 303-4 — free with an LRA Community membership. Register once (it's free) and every download unlocks, together with the Disclosure Library, templates and the LRA AI Assistant.
Assurance readiness
For each claim, check the evidence
| Claim | Risk | Evidence to check |
|---|---|---|
| Reporting period is reported accurately and completely. | The response omits, misclassifies or overstates reporting period. | Approved source records, calculation files, reconciliations and review evidence supporting reporting period. |
| Organizational scope is reported accurately and completely. | The response omits, misclassifies or overstates organizational scope. | Approved source records, calculation files, reconciliations and review evidence supporting organizational scope. |
| Total discharge in ML is reported accurately and completely. | The response omits, misclassifies or overstates total discharge in ml. | Approved source records, calculation files, reconciliations and review evidence supporting total discharge in ml. |
| Surface-water discharge is reported accurately and completely. | The response omits, misclassifies or overstates surface-water discharge. | Approved source records, calculation files, reconciliations and review evidence supporting surface-water discharge. |
| Groundwater discharge is reported accurately and completely. | The response omits, misclassifies or overstates groundwater discharge. | Approved source records, calculation files, reconciliations and review evidence supporting groundwater discharge. |
| Seawater discharge is reported accurately and completely. | The response omits, misclassifies or overstates seawater discharge. | Approved source records, calculation files, reconciliations and review evidence supporting seawater discharge. |
| Third-party water discharge is reported accurately and completely. | The response omits, misclassifies or overstates third-party water discharge. | Approved source records, calculation files, reconciliations and review evidence supporting third-party water discharge. |
| Municipal sewer mapped to third-party water is reported accurately and completely. | The response omits, misclassifies or overstates municipal sewer mapped to third-party water. | Approved source records, calculation files, reconciliations and review evidence supporting municipal sewer mapped to third-party water. |
| Third-party water sent for use is reported accurately and completely. | The response omits, misclassifies or overstates third-party water sent for use. | Approved source records, calculation files, reconciliations and review evidence supporting third-party water sent for use. |
| Reuse volume treated as subset is reported accurately and completely. | The response omits, misclassifies or overstates reuse volume treated as subset. | Approved source records, calculation files, reconciliations and review evidence supporting reuse volume treated as subset. |
| Freshwater ≤1 000 mg/L TDS — all areas is reported accurately and completely. | The response omits, misclassifies or overstates freshwater ≤1 000 mg/l tds — all areas. | Approved source records, calculation files, reconciliations and review evidence supporting freshwater ≤1 000 mg/l tds — all areas. |
| Other water >1 000 mg/L TDS — all areas is reported accurately and completely. | The response omits, misclassifies or overstates other water >1 000 mg/l tds — all areas. | Approved source records, calculation files, reconciliations and review evidence supporting other water >1 000 mg/l tds — all areas. |
| Total discharge in stressed areas is reported accurately and completely. | The response omits, misclassifies or overstates total discharge in stressed areas. | Approved source records, calculation files, reconciliations and review evidence supporting total discharge in stressed areas. |
| Freshwater — stressed areas is reported accurately and completely. | The response omits, misclassifies or overstates freshwater — stressed areas. | Approved source records, calculation files, reconciliations and review evidence supporting freshwater — stressed areas. |
| Other water — stressed areas is reported accurately and completely. | The response omits, misclassifies or overstates other water — stressed areas. | Approved source records, calculation files, reconciliations and review evidence supporting other water — stressed areas. |
| Credible public water-stress methodology is reported accurately and completely. | The response omits, misclassifies or overstates credible public water-stress methodology. | Approved source records, calculation files, reconciliations and review evidence supporting credible public water-stress methodology. |
| Catchment-level assessment is reported accurately and completely. | The response omits, misclassifies or overstates catchment-level assessment. | Approved source records, calculation files, reconciliations and review evidence supporting catchment-level assessment. |
| Priority substances treated is reported accurately and completely. | The response omits, misclassifies or overstates priority substances treated. | Approved source records, calculation files, reconciliations and review evidence supporting priority substances treated. |
| Definition criteria is reported accurately and completely. | The response omits, misclassifies or overstates definition criteria. | Approved source records, calculation files, reconciliations and review evidence supporting definition criteria. |
| International standard or authoritative list is reported accurately and completely. | The response omits, misclassifies or overstates international standard or authoritative list. | Approved source records, calculation files, reconciliations and review evidence supporting international standard or authoritative list. |
| Limit-setting approach is reported accurately and completely. | The response omits, misclassifies or overstates limit-setting approach. | Approved source records, calculation files, reconciliations and review evidence supporting limit-setting approach. |
| Incidents of non-compliance is reported accurately and completely. | The response omits, misclassifies or overstates incidents of non-compliance. | Approved source records, calculation files, reconciliations and review evidence supporting incidents of non-compliance. |
| Occasions of exceedance is reported accurately and completely. | The response omits, misclassifies or overstates occasions of exceedance. | Approved source records, calculation files, reconciliations and review evidence supporting occasions of exceedance. |
| Treatment-level breakdown is reported accurately and completely. | The response omits, misclassifies or overstates treatment-level breakdown. | Approved source records, calculation files, reconciliations and review evidence supporting treatment-level breakdown. |
| Basis for treatment levels is reported accurately and completely. | The response omits, misclassifies or overstates basis for treatment levels. | Approved source records, calculation files, reconciliations and review evidence supporting basis for treatment levels. |
| Supplier minimum-standard percentage is reported accurately and completely. | The response omits, misclassifies or overstates supplier minimum-standard percentage. | Approved source records, calculation files, reconciliations and review evidence supporting supplier minimum-standard percentage. |
| Measured and estimated data separated is reported accurately and completely. | The response omits, misclassifies or overstates measured and estimated data separated. | Approved source records, calculation files, reconciliations and review evidence supporting measured and estimated data separated. |
| Destination reconciliation is reported accurately and completely. | The response omits, misclassifies or overstates destination reconciliation. | Approved source records, calculation files, reconciliations and review evidence supporting destination reconciliation. |
| TDS reconciliation is reported accurately and completely. | The response omits, misclassifies or overstates tds reconciliation. | Approved source records, calculation files, reconciliations and review evidence supporting tds reconciliation. |
| Stressed-area subset reconciliation is reported accurately and completely. | The response omits, misclassifies or overstates stressed-area subset reconciliation. | Approved source records, calculation files, reconciliations and review evidence supporting stressed-area subset reconciliation. |
| Link to GRI 3-3 is reported accurately and completely. | The response omits, misclassifies or overstates link to gri 3-3. | Approved source records, calculation files, reconciliations and review evidence supporting link to gri 3-3. |
| Links to GRI 303-1, 303-2, 303-3 and 303-5 is reported accurately and completely. | The response omits, misclassifies or overstates links to gri 303-1, 303-2, 303-3 and 303-5. | Approved source records, calculation files, reconciliations and review evidence supporting links to gri 303-1, 303-2, 303-3 and 303-5. |
| Reason for omission is reported accurately and completely. | The response omits, misclassifies or overstates reason for omission. | Approved source records, calculation files, reconciliations and review evidence supporting reason for omission. |
Evidence pack to prepare
Common reporting gaps
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Framework references
Relevant GRI requirements and related disclosures
Available framework references and nearby disclosures relevant to preparing this requirement.
GRI
GRI 303-4
within GRI 303: Water and Effluents
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