Background The Lambro river is an important water basin located in the Lombardy region of northern Italy. It has been seriously affected, over the past two centuries, by industry-related pollution. Although the implementation of purification systems and other mitigating measures has decreased pollution levels, river quality has dramatically and severely plummeted following an ecological disaster that occurred in February 2010, when, as a result of criminal sabotage, 2 600 m3 of oil spilled into the river, causing a major ecological disaster for the water basin. The malfunction of the sewage network and episodes of illegal discharge of pollutants into the river have added to the critical conditions. The river’s middle course, around Merone (the main target of this project) is particularly polluted. The fish community is almost absent, macrobenthos (organisms living on or in the bottom of bodies of water) are scarce, and the Extended Biotic Index (i.e., measure of water quality) generally low. There is a need for a reduction in water risk and pollution, as well as habitat restoration and information and awareness-raising among the local population in order to stop the overall degradation of the river ecosystem. Objectives The project’s main objectives are: To develop an agreed, joint strategy for practical actions to address the water risk/ pollution problems and to devise a model for similar future interventions in the Lambro river basin: This agreement will ensure the maximum level of involvement of all stakeholders; and To improve the quality of surface water; To improve the habitat of the river and river basin areas; and To increase the biological connectivity between surrounding nature areas to help preserve and increase the natural habitats and species by improving the ecological regional corridors of the Lambro river. Specific actions to improve surface water quality will include: The creation of filter ecosystems, based on water phytopurification techniques that would be used, in first instance, for treating the water coming out of purifiers located in Merone and Nibionno; Removal of pollution sources in the three minor ‘affluent’ watercourses in Inverigo; Creation of filter ecosystems in the three minor affluent watercourses in Inverigo; and The creation of a permanent wet area between Inverigo and Nibionno. Expected results The main expected results include: The involvement of all stakeholders (over 200 technicians, civil servants, cultural and environmental specialists and a significant number of members of the general public) in the decision-making processes; Quality improvements in the effluent from the Merone and Nibionno treatment plants, including reducing total nitrogen and phosphorus levels by some 25-30%; and more closely matching the effluent temperature to the temperature of the water in the receptor; Quality improvements in the water of the three affluent watercourses in the Inverigo territory. Including: a 20% decrease in total nitrogen and phosphorus levels; and an increase in dissolved oxygen and subsequent decrease of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) by some 20%; Quality improvements in the habitats of the target river section – i.e. overall increased biodiversity supporting more birds and fish; and The establishment of new environments characterised by different plant systems typical of transition bands (reeds, shrubs and trees) enabling the establishment of new habitats for possible colonisation by other animal and plant species.