Managing natural resources involves reconciling diverging interests that often lead to conflict, which can lead to exploitation, environmental destruction and deteriorating livelihoods. Thus, managing conflicts in a peaceful manner is decisive not only for successful and sustainable resource management but for societal stability in general. Despite this connection, the knowledge and experience gained in the fields of conflict transformation and peace-building in the last decades has not been translated into user-friendly resources that can be easily understood by natural resource managers without prior experience in these fields. This handbook is trying to help fill this gap. It is intended to support participatory sustainable resource and conflict management efforts using the "Collaborating for Resilience" approach and is particularly useful for managing local conflicts over aquatic resources. The approaches and tools described are tailored toward local and community-based conflicts, such as those between different communities, between communities and government agencies, or between communities and commercial actors. The handbook and toolkit targets practitioners with experience in water and aquatic resource management, or natural resource management more broadly, but with little or no conflict management experience.