The macroinvertebrate community structures of three Michigan streams were examined through an annual cycle. Study sites were located above and below known sources of human disturbance on each stream. Taxonomic composition, standing crops, and diversity of both numbers of individuals and biomass were used in an attempt to describe the effects of cultural development on the streams. Macroinvertebrate diversity indices calculated using numbers of individuals found to be more sensitive than other indicators of human perturbation, particularly when comparing sections of any given stream. The city of Grayling's sewage treatment plant's conversion to land disposal resulted in increased diversity of the lower Au Sable River from an earlier study. (Modified author abstract)