A study conducted by researchers at North Carolina State University highlights the potential risks to water quality from converting forests into urban or agricultural land near streams. The research, published in PLOS Water, uses the Soil and Water Assessment Tool to evaluate current and future impacts of land-use changes on 15 water intake locations across the Middle Chattahoochee watershed in Georgia and Alabama.
Katherine Martin, an associate professor at NC State University and co-author of the study, explained that when forest cover is replaced with other land uses, water quality declines. “In terms of aspects of water quality that we have long-term data on, two of the biggest are nitrogen levels and the amount of sediment in the water. Looking at those two, in places where we’re losing forest cover, we see both of those increasing,” she stated. “Those are both detrimental to the quality of drinking water, and they require more filtration.”
The study indicates that increased fertilizer use in agriculture and impermeable surfaces from urban development contribute to higher sediment levels in waterways. This can lead to increased costs for water treatment facilities, particularly affecting smaller communities.
Martin emphasized that while agriculture and urban development have benefits, there are trade-offs when forest cover is lost. “What we are seeing is that there are tradeoffs when we lose forest cover, and we need to open up the conversation about those,” she said.
The research was supported by the U.S. Department of Agriculture Forest Service Southern Research Station. Co-authors include Elly T. Gay from NC State’s Department of Forestry and Natural Resources and Peter V. Caldwell from the Center for Integrated Forest Science.
The findings underscore the importance of considering forest conservation as a strategy for protecting water resources amid ongoing development pressures.
