**1. Introduction**

Water Footprint (WF) as a metric of water consumption and pollution along the production chain of a good or a service [1] has evolved during the last two decades into a popular environmental indicator and a valuable tool for water managemen<sup>t</sup> schemes' development at many levels. Since its first introduction in 2002, numerous WF assessments have been carried out [2,3], providing a large database of product, process and service water footprints. Its application in agriculture, a major water user, provides a clear indication of global crop water consumption and pollution patterns.

Despite its popularity among scientists and policy makers, slower uptake has been noticed at the farmers' and consumers' levels [4], probably due to the significant spatiotemporal variability of WF values that affect its comparability. At the field level, WF computation and further analysis of its components is valuable for farmers, since it provides an explicit insight into the general water managemen<sup>t</sup> pattern followed, such as the degree of rainwater exploitation as a means of fresh water saving or the degree of water pollution caused by irrational agronomic practices related to fertilization and plant protection. The question that usually arises after computing the WF of a crop is the actual meaning of the WF value as far as further action and response formulation are concerned. Mekonnen and Hoekstra [5] proposed the comparison of a WF of a crop with reference levels of WF and for that reason they have developed global WF benchmark values for crop production. However, although global benchmarks are significant tools for the design and implementation of global policies, at the farmers' level they do not offer practical normalized information since site-specific climatic conditions, soil nutrients and plant health status affect applied agronomic practices depicted in WF computations, and thus the results are not fairly comparable.

Communication of WF to the wider public is a core issue in the growing global market of green products. Water footprint labeling as proposed by Hoekstra et al. [1] can either

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**Citation:** Fotia, K.; Tsirogiannis, I. Water Footprint Score: A Practical Method for Wider Communication and Assessment of Water Footprint Performance. *Environ. Sci. Proc.* **2023**,*25*, 71. https://doi.org/10.3390/ ECWS-7-14311

Academic Editor: Athanasios Loukas

Published: 3 April 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

include the total WF of the product and/or the specification of its components, the degree of environmental sustainability achieved or the volume of water consumption compared to a reference year. The above either offer little or incomplete information regarding applied cultivation practices, require further analysis in order to be comprehensive, or lack comparability. Consumers need to be provided with complete and comprehensive information in order to "reward" farmers' actions towards sustainable water management.

The objective of the present study was to develop a simple and practical method for assessing and communicating in a single score WF performance of an agricultural product at the field level. We introduce the concept of "Water Footprint Score", a comprehensive and comparable indicator of farmers' water resources managemen<sup>t</sup> performance, which can be easily incorporated into agricultural products' labels.
