In a rapidly urbanizing world, population densities no longer allow for unlimited access to safe water. Competition for water, often associated with competition for the access to land, tends to be exacerbated in peri-urban areas. The objective of this paper is to propose a multiagent model prototype to represent the relationships between urbanization dynamics and land and water management in a peri-urban catchment area. A spatially explicit pilot model was developed using the Cormas platform. This prototype deals with a catchment that is the main drinking water reservoir and spring of a metropolitan area, and is subjected to high urban pressure and problems of pollution connected to land use and rain. The combined use of cellular automata, spatialized passive entities and communicating agents allows the articulation of the connections between hydrological processes (water cycle, pollution), land-use changes and urbanization. However, the representation is based on simplified dynamics and further work is needed to develop a simulation model that could be used as a discussion tool for land and water management at the urban edge.