1 This document specifies requirements and contains guidance for its use in establishing, implementing and maintaining a water efficiency management system. It is applicable to organizations of all types and sizes that use water. It is focused on end-use consumers.This document is applicable to any organization that wishes to: a) achieve the efficient use of water through the ‘reduce, replace or reuse’ approach; b) establish, implement and maintain water efficiency; c) continually improve water efficiency. This document specifies requirements and contains guidance for its use regarding organizational water use. It includes monitoring, measurement, documentation, reporting, design and procurement practices for equipment, systems, processes and personnel training that contribute to water efficiency management. NOTE1 ‘Reduce’ includes the use of water-efficient fittings and equipment and, for example, putting in place a proper monitoring system for usage and leak detection. NOTE2 ‘Replace’ includes substitution of drinking water with reclaimed water, sea water and rainwater wherever feasible. NOTE3 ‘Reuse’ includes recycling of, for example, process water or grey water. For utilizing water reuse systems, ISO/TC 282 documents can be referred to as guidelines. NOTE4 Guidance in the annexes provides additional practical information to support implementation. AnnexA provides guidance on the use of this document and AnnexB gives examples of scenarios in water efficiency.