Sustainable Development Goal 6 (SDG-6) aims to ensure universal and equitable access to clean water and sanitation while improving water resource management worldwide. Although this goal is crucial for achieving a sustainable future, its implementation often focuses on large-scale solutions, overlooking the importance of integrating it into local and educational environments. This chapter presents a case study of “Champagnat” Marist School located in the town of Salamanca (Spain), that it has incorporated the work of the SDGs into its three-year strategic plan. This plan ultimately takes shape through the work on the SDGs in the Curricular Project and in its daily practices. Strategies that have been implemented to promote the SDGs are analyzed, specifically objective number 6, the efficient use of water and sanitation, in all educational stages, from early childhood education to secondary education and high school. The involvement of the school community in the implementation of SDG-6 is described, including raising awareness and educating students, as well as actively engaging parents and school staff in decision-making and sustainable practice implementation. Furthermore, the challenges encountered in implementing SDG-6 in an educational setting are discussed, along with recommendations for getting over them. This case study demonstrates that the implementation of SDG-6 in an educational center is feasible and effective and it can have a significant impact on promoting sustainable practices within the local community. It is concluded that education on SDG-6 is essential for achieving a sustainable future, and that integrating sustainable practices into educational environments is a valuable way to promote change toward a more sustainable world.