Book excerpt: Forests and water are inextricably linked, and people are dependent on forested lands to provide clean, reliable water supplies for drinking and to support local economies. These water supplies are at risk of degradation from a growing population, continued conversion of forests to other land uses, and climate change. Given the variety of threats to surface water, it is important for forest managers to know how much of the drinking water supply originates in forests they manage and what populations and communities are served by that water. The objective of this analysis was to address this need by 1) estimating how much fresh surface water supply in the South originates from NFS lands and State and private forest lands, and 2) estimating how many people and which communities in the South depend on this fresh surface water supply. Of the 6,188 intakes, 3,143 received more than 20 percent of their water from State and private forest lands and served 29.0 million people. These results highlight the importance of southern forests in providing clean and dependable water supplies to downstream communities.