Studies utilizing volunteer stream monitoring data are rare, particularly in in the Atlanta metropolitan area. This study investigated how the macroinvertebrate communities of 20 different stream sites in the south metropolitan Atlanta area were affected by the imperviousness of their surrounding watersheds. These sites were in a diverse landscape which included forests, wetlands, suburban day-use parks, and parking lots. Percentage impervious surface area was measured using Geographical Information System (GIS) analysis. Macroinvertebrates were collected using Georgia Adopt-A-Stream’s volunteer monitoring protocols, and a water quality index (WQI) was calculated from these data. The relationship between WQI and imperviousness was curvilinear and best fit by a quadratic equation. In watersheds having more than 8% imperviousness, WQI clearly decreased.


The author thanks Georgia Adopt-A-Stream, Lake Spivey Rotary Club, Reynolds Nature Preserve, Henry County Storm Water Management Department, City of Griffin Storm Water Management Department, and Clayton State University for their cooperation and support of this study. The author also thanks his many research students, for their help and inspiration, including (in chronological order): Anne Stahley, Brett Williams, Jennifer Webb, Denisse Iacobucci, Kevin Washington, Samantha Ortega, Johnny Ly, Chau Hau, Justin Agan, Crystal Seckendorf, Loc Bui and Vickie Vo. Lastly, several people, including several anonymous reviewers provided very helpful comments that were crucial in the development of this manuscript.