Objective of the three-year monitoring study on the Peugue, which started in 1996, was to understand the effects of wet weather flows and runoff pollutants on the Peugue ecosystem from upstream to downstream, in order to design an optimal management program for flood protection while maintaining protection for the Peugue ecosystem, and then to develop a transposable general methodology for measuring the effects of stormwater on the aquatic ecosystem. During rainfall events, the Peugue river is used as a separate stormwater sewer system. The basin drains a 676-ha semi-urban area. In the upstream part of this catchment, the residential development is new and sparse with many wooded areas. Housing becomes more and more dense in the downstream part. The descriptive linear approach of the Peugue stream allowed the highlighting of various basic elements relative to the functioning of this system. On a hydrological level, the inertia of the flow related to the rain is weak. The flow variations (measured at Le Burck) are significant and sudden, able to pass in one hour from a few tens of l/s to more than one m3/s. From the whole of the analytical results obtained, the physicochemical quality of the Peugue water arises strongly degrading from upstream to downstream. The metal contents of the sediments are in the same order of magnitude as those measured on surface corings carried out in the laying-up of Bourgailh basin. Macrophyte index results are in good coherence with the results of physicochemical quality of water. This is particularly well illustrated between Peugue and its affluent. More generally, a good correlation between the various biological (macrophytes, diatoms) and physico-chemical parameters and the various discharges indexed is registered
