North Georgia experienced winter and spring rainfall amounts in 2007 that were approximately 30% lower than the long term average.  Annual measurements of riverweed (Podostemum ceratophyllum; a rheophilic macrophyte) occurrence from 2004-2007 at 11 sites in the Etowah River enabled us to evaluate the impact of drought on this species.  Riverweed occurrence significantly increased as both precipitation and stream flow decreased, with occurrence 6-13% higher in 2007 than in previous years.  Although the likelihood of riverweed presence on rocks increased significantly as rock size increased, the strength of this effect depended on precipitation levels.  Because riverweed is an important habitat component for several rare and endemic fishes and insects, changes in the occurrence of riverweed is likely to have repercussions for the river ecosystem. The reduction in precipitation experienced in 2007 is of similar magnitude to that predicted for 2040-2060 in two climate models.  Assessing the response of this species to drought may provide insights into potential ecosystem changes under future climate conditions.