Author's description: A RPG called KatAware was developed within a project based on an approach called Companion Modelling to reproduce the functioning of a real catchment, the Kat River, and allow local stakeholders (members of a Water User Association) to play around water management in order to: Understand the complexity of the system; Understand the relations between agents; Understand the impact of different water allocation strategies on the water flows, the profits, employment, and domestic users' satisfaction; Build up a catchment strategy within the Water User Association