<p>This study presents a bioassessment of lowland streams in the Shivalik Himalayas, utilizing benthic macroinvertebrates as bioindicators to evaluate the ecological health of the streams. Lowland streams of Shivalik Himalayas were assessed to analyze the diversity and distribution of macroinvertebrate communities in relation to various physicochemical parameters and anthropogenic influences. The results revealed significant variations in water quality across the sites, with key parameters such as pH, dissolved oxygen, conductivity, and nutrient levels influencing the assemblage patterns of macroinvertebrates. The water quality at different locations based on macro-invertebrate available taxa has also been validated using WAWQI (Weighted Arithmetic Water Quality Index). The study identified 25 families of benthic macroinvertebrates, encompassing 11 taxonomic groups, with notable variations in abundance and diversity among sites. Three biotic indices—BMWP/ASPT (Biological Monitoring Working Party/Average Score Per Taxon), FBI (Family Biotic Index), and HKHBIOS (Hindu Kush Himalayan Biotic Score) were used to evaluate the water quality, showing moderate to good ecological conditions at less disturbed sites and indicating pollution and degradation at sites with higher anthropogenic activities. Statistical analysis by using ANOVA showed significant differences among the biotic indices applied. The findings highlight the utility of benthic macroinvertebrates as reliable bioindicators for assessing stream health and underscore the need for integrated management strategies to mitigate anthropogenic impacts on freshwater ecosystems in the Himalayan region.</p>