Multiple decision makers and managers, competing interests and values, scarcity of resources, complex legislative requirements, and vast uncertainties about the future due to a more connected and rapidly changing world and the impacts of climate change, are just some of the issues that impact upon the capacity to carry out effective water planning and management. Throughout the world these issues are becoming increasingly difficult to handle, and there have been calls for more adapted approaches to aid the decision making processes required for water planning and management. Participatory risk management approaches appear appropriate to such situations as they can be designed to increase collaboration and manage conflict, explicit uncertainties, and structure complexity in more understandable forms. This paper will outline some insights and lessons learnt from the design and implementation of two different participatory risk management processes for water planning and management: a values-based method based on the Australian and New Zealand Standard for Risk Management for the development of the Lower Hawkesbury Estuary Management Plan in Australia; and a participatory modelling approach to manage the risks of living with floods and droughts in the Iskar basin in Bulgaria. Both processes were designed and implemented with the aid of researchers, local managers, government representatives at various levels of jurisdiction, community stakeholders and external legislative, scientific or engineering experts. The Australian process was an initiative driven and funded by the Hornsby Shire Council, a peri-urban municipality of Sydney. It consisted of three interactive stakeholder workshops with an average of 20 participants, held over a period of four months, as well as an external scientific and legislative review. The workshops focussed on establishing estuarine values, issues and current management practices; performing a risk assessment based on the stakeholder defined values (assets) and issues (risks); and formulating strategies to treat the highest prioritised risks as input to the estuary management "risk response" plan. The Bulgarian process in the region of Sofia formed part of the European Project "AquaStress", funded by the European Union, and was primarily driven from a research perspective. The participatory process was more elaborate in design than the Australian process with around 60 stakeholders divided into 6 groups taking part in a series of 15 workshops, individual interviews and evaluation exercises over a one year period. The process included cognitive mapping of the current management context and physical system, values, visions and preference elicitation for actions, strategy development and evaluation. Both cases provided rich insights into the value and constraints of participatory risk management approaches in different regulatory and political environments, as well as some important recurrent issues that organising teams of participatory approaches need to appreciate including: impacts of last minute process changes; how to deal with divergent objectives in a multi-institutional organising team; and the unintended ethical issues that can arise when working in "real-world" management situations. Increasing awareness of the value and potential issues associated with participatory risk management approaches should aid their adoption and the subsequent improvement of water planning and management around the world.