The New Zealand Water and Wastes Association published the original New Zealand Inflow and Infiltration (I/I) Control Manual in 1996. As part of its renewed focus to provide its membership with improved access to the latest technical knowledge and skills, Water New Zealand has recently developed and published the Inflow and Infiltration Control Manual 2nd edition (The Manual) to provide new information, methods, and technologies related to the management and reduction of wastewater system I/I The Manual is intended for wastewater managers, planners, engineers, and operations and maintenance staff who are currently undertaking I/I management, or who are interested in doing so in the future. By drawing upon current good practices and project experience from sources around the world, the Manual is considered the single source of current global best practice. By providing prediction tools and good practice methodologies, the Manual facilitates the reduction of risk and uncertainty in I/I projects and programmes. As a document that includes information applicable to both asset managers and practitioners, it is a comprehensive guide for I/I management in New Zealand.