The Water Footprint Network’s Water Footprint (WF) is an indicator of the volume of freshwater consumed and/or polluted to produce the goods and services consumed by an individual or community or produced by a business. The Water Footprint is a geographically and temporally explicit indicator which can be used to quantify both direct (operations) and indirect (supply chain) water use. Water Footprints (WFs) are intended to allow these entities to better understand their relationship with watersheds, make informed management decisions, and spread awareness of water challenges worldwide.

WFs are divided into three separate components—blue, green, and grey—all of which are expressed in terms of water volume. These components are meant to be considered separately or combined as a total WF. The three WF components are defined as follows:

  • Blue water – the volume of surface or groundwater consumed.
  • Green water – the volume of rainwater (found in soils rather than major bodies of water) consumed through evapotranspiration.
  • Grey water – a measure of the amount of the assimilative capacity of a water body used; the volume of water needed to dilute pollutants discharged to water bodies such that water quality standards are met.

Corporate WFs measure the total volume of water used directly and indirectly to run and support a business. A WF can be scoped to focus at the company-wide or facility level but can also focus on specific products. The corporate water footprint is equal to the sum of the direct and indirect water footprint (i.e., raw material production, manufacturing, and distribution) for all of its products.

The Water Footprint Assessment Tool (WFAT) – released in 2012 – greatly expands the scope and functionality of WFN water footprints.

Application

Water Footprint

Primary Functions
  • Good tool for “big picture” strategic planning purposes
  • Most commonly used for water use assessments, as opposed to water quality
  • Can be an effective public-awareness building tool
Assessing Water-Related Business Risks
  • Identifies “hotspots” linking corporate consumptive water use and source water data
  • Green/blue WF distinction helps shed light on nature of risk
  • Can be used at watershed level to understand proportional share of green/blue/grey WF relative to other water users
Understanding and Responding to Water Use and Quality Impacts
  • WF calculation does not attempt to quantify water-related impacts
  • Green/blue WF distinction illustrates general extent and type of impact
  • Grey WF underdeveloped/underutilized – focuses on primary pollutant and calculates theoretical volume of dilution water needed to reach regulatory standards
  • Water Footprint Assessment Tool assesses the sustainability of WFs (i.e., green/blue/grey WF relative to green/blue/grey water availability)
Conveying Water Information to Stakeholders
  • Easily understood by non-technical audiences
  • Conducive to business engagement with water resource managers
  • Water Footprint accounts and targets can be used in corporate reporting