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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
RK 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

Effective

2021-01-01

Official source: Open ↗

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
+ Show GRI 303-4 sub-elements (LRA working checklist)

How to prepare it

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.
Collect and reconcile the records for: 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.
Apply Disclosure 303-4 when the related topic is material and this disclosure is relevant to the organisation's impacts, or when an applicable GRI Sector Standard identifies it for reporting.
Draft the response using the defined terms shown in the disclosure focus; do not substitute broader internal labels.
Review the final wording against every requirement and the supporting governance or data records before sign-off.

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.

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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.

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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

Using internal destination categories without mapping them to the GRI destinations.
Confusing incidents of non-compliance with occasions on which limits were exceeded.
Using internal labels in place of the defined GRI terms.
Leaving a required preparation field unsupported by traceable evidence.
Treating GRI recommendations as mandatory requirements or mandatory requirements as optional.
Publishing estimates, exclusions or partial scope without methods, assumptions and the applicable reason for omission.
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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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