Water Consumption Tracking for Sustainability Reporting: A Practical Guide

Water consumption has become a critical metric in ESG reporting, particularly for suppliers in manufacturing, food processing, and other water-intensive industries. If you've received a customer ESG questionnaire asking about water usage, you're not alone. Understanding how to measure and report this data accurately can make the difference between a quick response and weeks of confusion.

Why Customers Ask About Water Consumption

Your customers need your water data for two main reasons: their own sustainability reporting requirements and supply chain risk assessment. Companies reporting to CDP Water Security, GRI standards, or pursuing SBTi targets must account for water use throughout their value chain. Additionally, they're assessing whether suppliers in water-stressed regions pose operational risks.

How to Measure Water Consumption

Reading Water Meters

The most accurate method is direct meter readings. Most facilities have water meters installed by utility providers, though larger sites may have sub-meters for specific processes. Record your meter reading monthly on the same date, note the units (usually cubic meters or gallons), and calculate the difference between readings.

If your meter displays in gallons, convert to cubic meters by dividing by 264.17. For example, 132,085 gallons ÷ 264.17 = 500 m³. Most international reporting standards require metric units.

Using Utility Bills

For facilities without accessible meters, utility bills provide consumption data. Look for the "usage" or "consumption" line item, not the cost. Bills typically show monthly consumption in m³ or kL (kiloliters, which equal m³). Keep 12 months of bills to calculate annual totals and identify seasonal patterns.

Be aware that some bills combine water supply and wastewater charges. You need the supply volume, which represents what you consumed. If your operation recycles water, you may need additional metering to capture total withdrawal versus discharge.

Calculating Water Intensity Metrics

Absolute consumption numbers matter, but questionnaires increasingly ask for water intensity, which relates water use to business output. Common denominators include:

• Per revenue: Total m³ ÷ annual revenue (example: 5,000 m³ ÷ $2M = 2.5 m³ per $1,000 revenue)
• Per production unit: Total m³ ÷ units produced (example: 5,000 m³ ÷ 50,000 units = 0.1 m³ per unit)
• Per employee: Total m³ ÷ employee count (example: 5,000 m³ ÷ 100 employees = 50 m³ per employee)

Water intensity allows year-over-year comparison even as your business grows. A 10% increase in absolute consumption paired with 20% revenue growth actually represents improved efficiency.

What ESG Questionnaires Typically Ask

Common questions include total annual water withdrawal (m³), withdrawal by source (municipal, groundwater, surface water), water discharge volume, whether facilities operate in water-stressed areas, and water recycling rates. Tools like ESG Passport help map these data points to various questionnaire formats so you're not answering the same question differently each time.

Questionnaires may ask about water stress using the WRI Aqueduct tool classification. Check your facility locations at wri.org/aqueduct to determine if you're in high or extremely high baseline water stress areas. Operations in these regions face additional scrutiny and may need to demonstrate mitigation strategies.

Building a Tracking System

Start simple: create a spreadsheet with columns for month, meter reading or bill date, consumption (m³), source type, and any notes about anomalies. Track each facility separately if you operate multiple sites. Set calendar reminders for monthly data collection.

As your reporting needs grow, consider whether you need automated tracking. If you're responding to more than four or five ESG questionnaires annually, the time savings from a centralized system become significant.

Water Quality and Discharge

Some advanced questionnaires ask about water quality parameters or discharge locations. While small suppliers rarely need this level of detail, be prepared to note if you discharge to municipal sewers (most common), surface water bodies (requires permits), or if you're in a zero-liquid discharge facility.

Moving Forward

Accurate water tracking starts with knowing where your meters are, establishing a collection routine, and understanding the units you're working with. The data you collect once can answer questions across multiple customer questionnaires, reducing the burden of ESG reporting. Focus on consistency and documentation, even if your current consumption seems modest. Baseline data from 2026 will prove valuable when customers ask for trend data in future years.