Community participation in water supply projects achieves maximum impact when the communities are motivated to participate in a subsequent health-related project. This report describes case studies of two villages in Togo and two in Indonesia where oral rehydration therapy (ORT) activities were introduced after the villagers had participated in the construction, operation, and maintenance of improved water supply systems. Findings indicate that water projects stimulate community participation in subsequent ORT activities when: (1) the health benefits of an improved water supply and the social benefits of community involvement are fully understood; (2) the village development committee (VDC) plays a motivating role in recruiting and influencing participation, rather than an implementing role; (3) the VDC and the village chief have structured reporting mechanisms for supporting and supervising community volunteers; (4) power is not centered in the village chief but shared with subchiefs; (5) ethnic groups receive equal representation in activities and decisions; (6) project workers speak the local dialect; (7) the village population is small; (8) villages are physically accessible for site visits and the delivery of goods and services; and (9) water quality is a problem more of health than of convenience. On the basis of these findings, the report presents recommendations for improving water and health policies and projects.