Most of streams suffered from anthropogenic pollution, such as untreated wastewater or insufficiently cleaned effluents of wastewater treatment plants (WWTP). The Vistre river (France) is one of these hardly damaged streams. In 2008 the WWTP closed and a new one, equipped with modern techniques and respecting the Europeans standards, was built 1 km downstream. The building of these efficient WWTP resulted in an enhanced purification of wastewater, leading to an improvement of stream water quality. The present study investigated the recovery of the aquatic ecosystem functioning after such modifications. Our objective was to assess the effects of the point source on the structure and functional organization of the macrobenthic community.Invertebrates and environmental parameters were collected upstream and downstream of the old and new point source inputs during the last 3 years (September 2007 to September 2009). Analysis carried out indicates that water quality and invertebrate abundance rapidly increase just after the old WWTP cessation whereas community structure is slower modified. Observed modifications in the functional structure suggest that traits could be useful to assess the effect of restoration management.