The focus of this publication is efficient water use in urban and domestic environments and decision-making about sustainable development of human settlements. The book is written as a Sourcebook, highlighting essential questions that will have different answers in different situations. By looking at water use efficiency within the context of sustainable water use, the emphasis is on the means for maximizing and optimizing between safe and sufficient supply and demand of water, and on articulating a key role for Environmentally Sound Technologies (ESTs). The Sourcebook entitled Every Drop Counts, -Environmentally Sound Technologies for Urban and Domestic Water Use Efficiency is meant for those involved in the public sector and experts as well as health and spatial planning departments, water board and water utilities/water works/drinking water company officials, NGOs and local communities dealing with water management. The Sourcebook gives a comprehensive overview on available ESTs and features for water use efficiency in the urban and domestic environment. It aims to enable the target audience in making plans for the identification and application of ESTs and to influence water use policy in the public sector through the application of ESTs. Based on the concept of Integrated Water Resource Management (IWRM) the sourcebook highlights political strategies and instruments that create conditions for the capacity building and awareness raising of actors on all levels (from local to city to country) and from all fields (from private to commercial to public).