What is Water Footprint Assessment ?
Water Footprint Assessment is a four-phase process that quantifies and maps green, blue and grey water
footprints, assesses the sustainability, efficiency and equitability of water use and identifies which
strategic actions should be prioritised in order to make a footprint sustainable.
Water Footprint Assessment is versatile and can inform a broad range of strategic actions and policies from environmental, social and economic perspectives.
These are the four phases of Water Footprint Assessment:
Goals and Scope
A Water Footprint Assessment begins with setting the goals and scope of the water footprint study. Water Footprint Assessment can be undertaken for diverse purposes.
For example, it can be undertaken to:
- Support a specific business on achieving sustainable water management within their direct operations and supply chain
- Support governments and regulatory agencies on national/regional sustainable water allocations and management
- Define benchmarks for water consumption and water pollution for a specific sector of activity or production of a specific product
- Raise awareness on water sustainability issues related to water use
A Water Footprint Assessment can be tailored to meet the goals and scope of the study. The goal of the
Water Footprint Assessment clarifies what you will do in the subsequent steps: accounting,
sustainability assessment and response formulation. The scope of the assessment defines the spatial and
temporal scale of the study, for example whether the focus will be global or within a single catchment,
whether it will span one year or multiple years, whether it will include some or all of the value chain,
address one product or a facility or an entire company.
Together, the goal and scope indicate which data will be used, how each subsequent step of the assessment will be approached and the level of detail required to achieve the desired results.
Once the goal and scope of the Water Footprint Assessment have been defined, the data are collected to calculate the footprint of the relevant processes for the study.
These may come from global databases, such as WaterStat, or collected locally. The calculations for the green, blue and grey water footprint follow the methodology described in the Water Footprint Assessment Manual.
Water Footprint Assessment is used to assess whether water use is environmentally sustainable, resource efficient and equitably allocated.
In the sustainability assessment step, we are assessing whether water use is balancing the needs of people and nature, if our limited water resources are being used to the greatest benefit and how fairly we are sharing the waters we use.
When we consider the environmental sustainability of water use from the perspective of water quality, we compare the grey water footprint with the available assimilation capacity to measure the water pollution level. If the grey water footprint exceeds the assimilation capacity water quality standards are violated and the quality of the water will not meet socially agreed upon purposes.
Both of these, blue water scarcity and water pollution levels, are assessing the cumulative impact of all water uses of the freshwater resource. This can be done for sub-catchment or a local aquifer all the way up to large river basins and regional groundwater reserves.
Using the information gained in the accounting and sustainability assessment steps of Water Footprint Assessment, response strategies that reduce the water footprint and improve its sustainability can be prioritised for implementation.
Response strategies can range from investing in better metering to enable improved water management, to changes in practices or investments in technology that will reduce the water footprint at any step along the value chain. It may also be important to take action collectively with others to improve the long-term sustainability of water use at the catchment or river basin level. Water stewardship and integrated river basin management engage a range of stakeholders in finding solutions which reduce wasteful water use and implement good water governance.