The provision of water and sanitation services in deprived urban settlements is a challenge faced by many countries in the South. The growth of towns and cities together with the rapid increase in urban populations has meant that peri-urban areas are growing much more quickly than formal urban centres. Low levels of services such as water supply and sanitation are the result. The lack of these services threatens not only the health and the environment of people in peri-urban areas, but also that of people living in formal urban areas.~~This paper, which is an output of a Sida/DFID and DANIDA funded project, provides a basis for better understanding of how to identify and build upon local initiatives that are likely to improve water and sanitation services in low-income neighbourhoods. The paper also describes how a local organisation in Ghana has managed to: scale up successful projects; work collaboratively; finance water and sanitation schemes; and use information systems such as mapping to drive local action and monitor improvements