GRI Water Reporting Ecosystem

GRI 303, ESRS E3, and CDP Water — the comparison

Three water disclosure frameworks are in active use — and their content overlaps significantly, making integrated data collection achievable.

GRI 303 (Water and Effluents 2018): The foundational voluntary standard covering water withdrawal (303-3), discharge (303-4), and consumption (303-5) — all broken down by water-stressed and non-stressed areas. Also covers qualitative disclosures on water interactions (303-1) and discharge impact management (303-2).

ESRS E3 (2023): The mandatory CSRD water standard. Substantially aligned with GRI 303 for quantitative metrics — withdrawal, consumption, recycled water, and discharge quality. Adds financial effects quantification (E3-5) absent from GRI 303. Slightly more prescriptive on stress area disclosure methodology.

CDP Water Security questionnaire (annual): CDP's voluntary water disclosure platform. Covers water risks, strategy, targets, governance, and performance data. The quantitative water metrics in CDP W6 (water accounting) align closely with GRI 303 metrics. CDP Water additionally covers supply chain water risks (W8) and water-related financial risks in more depth than GRI 303.

For dual reporters: GRI 303 data satisfies CDP Water quantitative metrics with minimal reformatting. ESRS E3 data satisfies GRI 303 with the addition of financial effects. A single water data collection programme serves all three frameworks — CDP adds the narrative risk assessment layer beyond raw metrics.

Water data collection — the integrated approach

A single water data collection programme can serve GRI 303, ESRS E3, and CDP Water simultaneously — reducing duplication and improving data quality through consolidated effort.

Step 1 — Site inventory: List all operational locations. For each, record: municipality/region and country; primary water source (municipal, surface, groundwater, rainwater); water metering availability (fully metered, partially estimated, estimated).

Step 2 — Stress area screening: Run all site locations through WRI Aqueduct Water Risk Atlas. Classify each site as water-stressed (High or Extremely High baseline water stress) or non-stressed. Record the Aqueduct stress score for each site — used in all three frameworks for stress area disclosure.

Step 3 — Water withdrawal data: Extract annual water volumes from utility invoices (municipal water), meter readings (private well or surface water abstraction), and water authority permits (abstraction licences showing actual vs permitted volumes). Aggregate by source type and by stressed/non-stressed designation.

Step 4 — Discharge data: Obtain wastewater discharge volumes from: municipal sewer discharge records; industrial effluent discharge monitoring reports; and environmental permit compliance data. Record discharge destination (municipal sewer, surface water, groundwater injection) and quality parameters (BOD, nitrogen, phosphorus, heavy metals).

Step 5 — Consumption calculation: Withdrawal minus discharge to same catchment = consumption. For companies discharging entirely to municipal sewer (treated off-site), consumption equals withdrawal unless water is incorporated into products or significantly evaporated.

Water risk and financial effects — the frontier disclosure

Water quantity and quality metrics (GRI 303, ESRS E3) are the established layer of water disclosure. The frontier — increasingly expected by investors — is water risk financial quantification.

ESRS E3-5 financial effects: Requires disclosure of anticipated financial effects from material water-related risks — operational disruption costs from water scarcity, regulatory costs from discharge permit tightening, capital costs of water treatment upgrades, and stranded asset risk in water-stressed locations. This is the most demanding element of ESRS E3 — few companies have mature water financial risk quantification.

CDP Water financial risk disclosure: CDP W5 requires disclosure of water-related financial risks that have or could have a substantive financial or strategic impact — including quantification of potential financial impact where possible. CDP's water risk framework (physical risk, regulatory risk, reputational risk) maps closely to ESRS E3-5.

Approach for water financial risk quantification: Start with physical water risk screening (WRI Aqueduct stress scores for operational sites). For high-stress sites, assess: production disruption risk if water availability is restricted (revenue at risk); cost of securing alternative water sources; capital expenditure required for water recycling infrastructure; and insurance cost trajectory for water-related business interruption. Range-based quantification (€X–€Y million) is sufficient for initial E3-5 disclosure.

For food and beverage companies: water-stressed agricultural supply chain is often the most material water risk — not direct operational water use. CDP Water W8 supply chain water risk and ESRS E3 value chain water impact disclosure both require this supply chain perspective. Commodity-level water risk assessment (Aqueduct Food tool for agricultural commodities) provides the screening methodology.

Frequently asked questions