The contents of this publication are the result of study and an effort to systematize the experiences of five successful associations, described here as Sustainability Centers for Community-based Water and Sanitation Organizations (CWSOs) in Honduras, Colombia, Ecuador, Brazil, and the United States, and one case from Tanzania, Africa. Fundación Avina gathered information on these cases and produced this document to serve as a reference for those countries wishing to implement Sustainability Center strategies to support the rural drinking water and sanitation sector.