Rwizi river, a major contributor to the waters of L. Victoria, is an important freshwater reserve and supports a large and rapidly growing population in Western Uganda. Though it is referred to as a life-line river, it is greatly disturbed by human activities but scanty information exists on extent of damage the river faces. A comprehensive study was made using biological and and physico-chemical aspects of the water to assess water quality along the river system. These data are for benthic macroinvertebrates of the Rwizi system from 21 sites sampled for six months, three in the wet season and three in the dry season. The data sheet contains the date of data collection, site name, season (wet or dry), macroinvertebrate orders and abundances under each macroinvertebrate family collected using the kick-sampling method. This data was used to compute diversity indices and to assess impact of human activity on water quality in urban, peri-urban and rural areas. The Bioassessment used was The Tanzania River Scoring System (TARISS) and classification of taxa was to the require level of classification (Baetidae and hydropsychidae further classification is not included here)
