The original WF method is not based on the carrying capacity
concept. This is a major draw back for its application to planning as
water supply by precipitation as well as groundwater are key
environmental services, varying from region to region. Aligning the
capacity of these services with human use within a given region in
a sustainable way is therefore a major challenge for the organisation
of water consumption as well as water infrastructure planning.
This paper has been inspired by the idea to ground WFs so that land
area once again becomes the methodological basis (as it is for EF)
and is driven by the aim of creating a newplanning tool for regional
or local water supplies. Hence, the new model presented here
converts the WF concept into a measure that takes the carrying
capacity into account. As both precipitation and other natural water
flows are bound to area, the natural carrying capacity with respect
to water consumption is also linked to area, comparable to the EF,
where productive land has to supply the resources for society in
terms of energy and materials. An area based WF, taking regional
supply variations for water into account will become a better
sustainability indicator and a valuable measure for strategic policy.
To avoid confusion with previous efforts, we label our concept
“water supply footprint” (WSF) e a measure bringing together the
amount of water available for a regional settlement based on the
land surface area in that region’s water supply hinterland (catchment-
based) and the way the water is used within a given region or
locale. The WSF targets at translating water planning information
into an intuitive measure that is related to spatial dimensions of
water consumption and can be understood by key actors of and
decision makers who make strategic decisions outside water
planning but have to considerwater issues at an early stage in order
to avoid environmental overshoot.