Forests Provide Clean Drinking Water for the South

Report provides new level of detail about water from National Forest System lands

beautiful leaf with drops


For over 19 million people in the South – roughly the population of Florida – clean water begins in the region’s national forests. That’s according to a report by the U.S. Forest Service Southern Research Station published in late 2014. The report provides information at a level not previously available on the amount of surface drinking water national forest lands provide to communities in the South, and features an appendix of maps that show in detail the water flowing from national forests in the South in relation to surface water intakes for nearby cities and towns.

The Forest Service Southern Region and Southern Research Station (SRS) worked together to produce the report’s analysis, tables, and the maps, which not only include detailed data on public water system intakes, but also number of customers served and percent of water originating on National Forest System lands for each of the 33 national forests managed by the Southern Region. The Southern Region manages over 13 million acres of forest land in the South, some 6 percent of total forest land in a region where most forests are privately owned.

“We identified specific communities and populations that depend on water originating from National Forest System lands and provided data quantifying the extent of that dependence,” said Peter Caldwell, research hydrologist at the SRS Coweeta Hydrologic Laboratory. “In all, National Forest System lands in the South contribute 8 trillion gallons per year to the total water supply of these communities.”

The report illustrates the extent to which people in the South depend on forested lands to provide them with clean reliable sources of drinking water. A combination of federal, state, and private forests cover over 30 percent of the region’s total land area and provide 36 percent of total water yield. More than 2100 individual communities rely directly on national forest land for drinking water, including large population areas such as Houston, Atlanta, Knoxville, and Birmingham.

Maintaining forest cover is an important way to protect water quality and regulate water flow. Most of the forest lands in the South are privately owned and are vulnerable to conversion to urban and other uses that result in costly tradeoffs including increased water treatment costs, increased frequency and severity of flood events, and degraded aquatic ecosystems.

The detailed maps in the report appendix can aid the partnerships needed to ensure the future availability of quality drinking water from forested lands in a region already experiencing water stress in some areas.  Partnerships among state, federal, and nongovernmental organizations are essential to ensure clean and dependable water supply in the future by keeping forest land in forests.

Access the full text of the report.

For more information, email Pete Caldwell at

Access the latest publications by SRS scientists.