This report was prepared to provide background information for participants in a workshop convened to develop science-based flow recommendations for Thurmond Dam that will enhance ecological conditions in ecosystems of the Savannah River below the dam. In the report we explore the extent of hydrologic alteration and the ecosystem flow requirements for the following reaches of the river: Augusta Shoals, Savannah River and floodplain below Augusta, and the estuary. Flow is clearly not the only regulator of ecosystem condition in these reaches; hence we have attempted to put flows into the context of other anthropogenic factors influencing ecosystem condition.