Background and Objectives: Water pollution is a significant public health threat, and traditional end-of-pipe solutions are inadequate for addressing diffuse, non-point source pollution. Integrated Watershed Management (IWM) offers a proactive, source-based alternative, but evidence linking IWM to actual health outcomes, rather than just water quality, remains scarce.
Methods: A comprehensive search was conducted across PubMed/Medline, Scopus, Web of Science, and Google Scholar for relevant studies up to 2026, using terms related to watersheds, pollution, and health. Studies were assessed based on design, outcome directness, and confounding controls, specifically targeting those with measured health outcomes and either pathogenic factors or surrogate exposure markers.
Results: Few studies provided direct health evidence, primarily from Asia and Europe. In India, IWM was linked to reduced faecal coliform levels (42% vs. 88%) and fewer diarrhoeal cases (18 out of 663 vs. 42 out of 639). In developing countries, increased upstream tree cover was associated with lower childhood diarrhoea rates, similar to the effects of improved sanitation. European studies found that wastewater contamination led to gastroenteritis outbreaks, and modeling suggested blue-green infrastructure reduced swimmer infection risk. Wider riparian buffers (over 50 meters) were more effective in removing nitrogen, whereas studies in North America, Africa, and South America mainly reported environmental indicators.
Conclusion: Although IWM presents a biologically sound approach, direct evidence of health benefits is limited and geographically uneven. Nonetheless, it is a viable source-protection strategy with potential health advantages. Further long-term, quasi-experimental studies in high-burden regions are needed to validate claims of reduced disease.