Abstract
Coastal areas are under the influence of discharges from nearby urban spaces during rainfall events. A multidisciplinary approach that combines hydrology and sociology is essential to take into account the strategies of urban planning in the physical modeling of rainfall-runoff modeling.Semi-structured interviews were carried out in the Montpellier area, with interlocutors chosen to be representative of local stakeholders in water management (elected officials, technical services, state services, associations, scientists), followed a focus group. The 24 interviews were oriented towards the perception and representations of the pollution generated by urban runoff and the interest of measures to reduce the imperviousness of the urban environment. They aimed to understand how local stakeholders seize on these questions and to measure the acceptance of the use of alternative techniques of urban planning. The persistence of heavy technical practices - stormwater basin - against gentle practices – rain garden - has been highlighted and compared to the practices developed in other territories. The effects of local cultures or preconceived ideas have been identified: the question of the quality of rainwater during all rainfall events emerges with difficulty against of the flooding risk in Mediterranean areas. The more targeted interviews and the focus group made it possible to point out the obstacles to the implementation of alternative techniques in the urban area of Montpellier.The results made it possible to propose very conventional urban planning scenarios: installation of pervious coverings on traffic routes (or park lots) or connection of runoff from roofs to permeable areas.