Fleet operators turn water savings into ESG data by recording each cleaning event — date, site, cars cleaned and the water method used — and aggregating those records into the water and Scope 3 figures their reports need. A conventional fleet wash uses 100–150 litres of water per car; a waterless valet draws none from the site, and the per-service record is what makes that difference reportable rather than a claim.
How much water does a fleet car wash use?
A conventional pressure-wash or rollover wash uses 100–150 litres of water per car. A waterless valet uses a small volume of pre-treatment applied by hand with microfibre, with no rinse stage and no run-off needing drainage. Across a fleet the difference is material:
| Method | Water per car | 200-car fleet, cleaned fortnightly (5,200 services a year) |
|---|---|---|
| Pressure wash / rollover | 100–150 litres | 520,000–780,000 litres |
| Waterless valet | None drawn from site | None drawn from site |
| Water avoided | 100–150 litres per service | 520–780 m³ a year |
That range is the figure to carry into reporting, with the per-car assumption stated alongside it. A range with its basis written down is auditable; a single rounded number is not.
Where do water savings sit in ESG reporting?
Where the saving lands depends on who was using the water before:
- ESRS E3 (water and marine resources). ESRS E3 asks for total water consumption in cubic metres from the undertaking’s own operations. If cars were washed at the fleet’s own sites from its own supply, that water was part of its consumption, and switching to waterless removes it.
- ESRS E1, Scope 3 Category 1. Outsourced cleaning is a purchased service. DEFRA’s 2026 GHG Conversion Factors for Company Reporting give water supply at 0.1913 kgCO2e/m³ and water treatment at 0.17088 kgCO2e/m³ — together 0.36218 kgCO2e/m³. On the 200-car example, avoiding 520–780 m³ a year corresponds to about 188–283 kgCO2e.
- CDP water security and supplier assessments. Questionnaires that ask for water use and reduction measures carry more weight with documented data behind them than with policy statements.
The structural point is that the fleet operator does not install anything. It chooses a supplier whose method draws no water, and the saving follows from the procurement decision — provided it is recorded.
How does a service record become an auditable data point?
Four fields per service event close the gap between “we use a waterless valeting company” and “here is our documented annual water saving”:
- date of service
- site identifier (outward postcode)
- number of cars cleaned
- water avoided, using a stated per-car assumption
Aggregated by quarter or year, those records map to a water-consumption or purchased-services entry in any reporting tool. The postcode field allows the figure to be split by area, which matters for operators whose sites sit in different water-stress classifications.
MMCC records every visit by date, site and registration, with each car’s 20-point Vehicle Health Check attached. Fleet records export as CSV, and ESG reports are downloadable as PDF through the Fleet Insight Platform, ready to feed into a spreadsheet, a consultant’s template or an ESG data platform.
What do auditors look for in a water-avoidance claim?
An auditor reviewing a water-avoidance figure asks three things of the data behind it:
- Is the per-car assumption documented and applied consistently across all records?
- Can service dates and sites be cross-checked against operational records?
- Is the arithmetic traceable, from each service entry to the quarterly total to the annual figure?
Dated service records with site identifiers and a stated per-car method answer all three. A supplier’s marketing claim pasted into a spreadsheet answers none of them. The same principle runs through our piece on evidenced fleet sustainability claims.
How should water reporting be written into a valeting tender?
Put it in the specification, so every bidder has to answer it before contract award. The language can be short:
Supplier to provide per-service environmental records including date, site postcode, number of cars and water-avoidance figure using a documented per-car method. Records to be supplied quarterly in a structured format suitable for ESG data entry.
That turns a water-saving claim from a marketing point into a deliverable the procurement team can score. The supplier either keeps per-service records or does not.
Why does water reporting matter more in the South East?
The Environment Agency classifies the Thames Water supply area as seriously water-stressed, which covers much of London and Surrey. For fleets operating there, documented water avoidance carries more weight with local planning authorities and in public-sector tenders than it would elsewhere.
Our rounds across the area include mobile car valeting in Kingston upon Thames and mobile car valeting in Guildford, and the reporting modules are set out on our Corporate fleet services page.
Fleet managers can map the water and Scope 3 data their fleet could be reporting through a Fleet Readiness Audit.