Environmental systems are usually extremely difficult to be undertaken by traditional software systems. This is due to the complexity of the environmental domain. Particularly, river catchment systems are very intricate to manage in order to achieve a good quality and quantity of water at the river. Multi-Agent systems (MAS) are able to cope with this complexity by integrating all the water systems involved at catchment scale through several agents who model real environmental situations. This work presents the development of our MAS prototype made in the agent platform Jadex. The design was made using the methodology Prometheus. The aim of our prototype is to provide feasible solutions at catchment scale throughout modelling and simulation of different scenarios in a river basin system.