The Etowah River is a major headwater tributary of the Coosa River system of the Mobile River drainage. Lying entirely within Georgia at the foothills of the Southern Appalachians, it originates in the Blue Ridge physiographic province but also drains Piedmont and Valley & Ridge provinces. Because the mainstem of the Coosa is impounded by reservoirs along most of its length, many species that were originally more widespread are now found only in the Etowah and other headwater tributaries. In fact, the Etowah itself is split by the 4800-hectare Lake Allatoona, and the imperiled mainstem species are only found above the reservoir.
The Etowah Basin lies on the north edge of the Atlanta metropolitan area. The suburban counties that comprise the lower portion of the system have been among the fastest growing counties in the nation over the last decade. In 1998, one of them (Forsyth County) was ranked as the fastest-growing county nationwide. Over the course of the 1990s the Atlanta metropolitan area added more people than any other region in the U.S. except Los Angeles.
Several sensitive small-stream fish species, including the Cherokee darter, appear to be declining. Small-stream habitat in the developed portion of the basin is generally poor, due in large part to upland development. Agricultural lands and forests are being converted to subdivisions, industrial parks, shopping malls, and other developments at a rapid rate. As a result, riparian vegetation necessary for stabilizing stream banks and protecting water quality is being cleared; runoff from upland areas has increased and is of poorer quality; and stream geomorphology is being altered by filling, piping, channelization, altered stream flows and other modifications. These changes in land use frequently cause accelerated erosion that covers streambeds with silt and reduces foraging and spawning success of aquatic species. Additional small-stream habitat has been inundated by water-supply reservoirs built to support the burgeoning human population.
While many of the mainstem aquatic species (such as the Etowah and amber darters) appear to be fairly stable, their range is limited to acceptable habitat in the Upper Etowah due to the presence of Allatoona Dam, a multi-purpose facility that evenly splits the river system. It is likely that unmanaged development along Etowah tributaries will lead to degradation of habitat and water quality in the mainstem and the further imperilment of these species.