The area of the Venice Lagoon plain is easily subject to eutrophication because of the agricultural activities located in the area. This case study aims to investigate how nature-based solutions (NBS) may contribute to reduce water pollution (main benefits) at sub-basin scale by retaining and processing diffuse pollutants generated by farming practices (Nitrogen, Phosphorus, sediments and pesticides) while delivering, at the same time, other benefits (Side Benefits) beyond water pollution control, such as shelters for biodiversity, amenity and recreational opportunities. 4 NBS have been investigated in this study: two wetlands (the Scolo Rusteghin site and the Salzano site), one buffer strip (Scandolara site), one woody buffer (NICOLAS site). The aim is to obtain the information necessary to upscale and estimate their environmental, social and economic benefits and costs on a sub-basin scale. The outcomes of the study showed that: NBS are effective in removing the nutrients and contaminants from diffuse pollution, displaying efficiencies in line with the scientific literature; NBS provide a high added value for the community every year; NBS need reasonable construction and O&M costs while providing several important benefits.