Developed in collaboration with United Nations agencies, civil society and other organisations, the United Nations challenge badges are intended to raise awareness, educate and motivate young people to change their behaviour and be active agents of change in their local communities. The challenge badge series can be used by teachers in school classes and by youth leaders, and especially Guide or Scout groups. This booklet includes basic background information on water, the water cycle and how water sustains life, as well as outlining why humans need clean water and sanitation to stay healthy. The badge looks at the different factors which affect our water supply (such as over-use, pollution, natural hazards and climate change) and considers how water can be conserved and used more efficiently. The second part of the booklet contains the badge curriculum: a range of activities and ideas to stimulate learning and motivate children and young people to save water and engage in efforts to increase equitable access to clean water.