Quantifying the Role of National Forest System Lands in Providing Surface Drinking Water Supply for the Southern United States
Forests and water are inextricably linked, and people depend on forested lands for 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. In this analysis, Forest Service scientists used a hydrologic model, Water Supply Stress Index (WaSSI), and a database of surface water intakes to quantify the extent to which people depend on surface water from Forest Service National Forest System (NFS) lands and state and private forest lands in the South. Of the 6,724 public surface water intakes in the South, 1,541 intakes serving 19.0 million people receive some water from all NFS lands in and upstream of the 13 southern states. Of the 1,541 intakes, 427 received more than 20 percent of their water from NFS lands and served 3.2 million people. These results highlight the importance of southern forests in providing clean and dependable water supplies to downstream communities.
Forest Service Partners