Southern Forests Lead to Increased Water Quality and Cost Savings Downstream
Keeping Forests has partnered with the USDA Forest Service Southern Research Station (SRS) and NC State University to answer a key question — what is the value of forests to water quality and quantity?
Across the U.S. South land is being consumed by development. In a region that is facing high pressure for land use conversion, a team of researchers set out to evaluate the relationship between land cover and water quality. The study found that conversion of natural land cover to non-forest uses can degrade water quality and increase treatment costs for Public Water Systems (PWSs).
“Our research team includes economists who will link water quality and water treatment costs," says Dr. Peter Caldwell, researcher with the USDA Forest Service, Southern Research Station. "This line of research could one day inform programs that compensate private forest landowners for the ecosystem services their forested watersheds provide.”
Fig. 1. Aggregated land cover (A), and the 1746 water utility facilities (B) across the South. land cover in (A) based on the 2011 NLCD. Utilities in (B) were designated as surface water source, community water systems, and an intake or reservoir in the EPA SDWIS database and are colored according to whether they occur on a reservoir/ lake/impoundment or are located on a run-of-river based on visual inspection. State abbreviations in (A) are: AL = Alabama, AR = Arkansas, FL = Florida, GA = Georgia, KY = Kentucky, LA = Louisiana, MS = Mississippi, NC = North Carolina, OK = Oklahoma, SC = South Carolina, TN = Tennessee, and VA = Virginia.
Land that has been traditionally agricultural and forested land is being converted at rates never before seen. According to the Southern Forest Futures Report, if the U.S. South continues to develop at its current rate, the region could lose up to 23 million acres of forested land by 2060. Along with losing the trees, the South would lose many co-benefits, also known as ecosystem services, such as clean water and air, wildlife habitat, and green spaces to recreate.
Why Is Water Valuation Needed?
Linking forests to water quality helps to illustrate the benefits of keeping forests as forests in key watersheds across the U.S. South. The team found that upstream land use has a direct impact on the quality of drinking water. They tested this using models that ran four types of land use: forested, agricultural, development and other natural uses. The models show that a watershed with greater forest cover leads to a reduction of costs for downstream water utilities. Approximately half of this region’s citizens rely on surface water – like streams, rivers, lakes, and reservoirs – for their drinking water. It's clear to see why protecting this region’s forestland is so important.
The research demonstrates the impact that a specific tract of forest has on sediment reduction. With less sediment comes clearer water and less turbidity. Public Water Service - PWS for short - use turbidity numbers to determine water quality standards and whether water meets its designated uses. Now that the ecological benefits have been clearly defined, the team is working with Southern water utilities to determine a dollar-value on the forests' ability to provide the ecosystem service of naturally filtering the water.
What Are The Next Steps?
The next step for the team is to combine the ecologic impact data with the economic valuation data to create a web-based, open-sourced application. This application (or Story Map) will enable government, utilities, non-government organizations and private landowners to understand the water-related values of private forests. They will then be able to apply the model to meet their mission-related goals. Ultimately, this work is an essential component to catalyze water markets.
The application is expected to be completed and available by early 2024.
How Do Water Markets Help Keep Forests as Forests?
In the U.S. South, eighty-six percent of the forests are owned by private landowners. These landowners rely on forest markets to get a return on their investment. “Without markets, we won’t be able to keep forests working,” says Scott Phillips, South Carolina’s State Forester. “If there aren’t economic incentives, forest landowners will be forced to convert that land to some other use.”
As the pressure of conversion increases, Keeping Forests and its partners are creating market-based solutions to promote the use and sustainability of southern forests. Outside of the traditional timber markets, a water market would allow a landowner to receive payments throughout the life cycle of forest. This payment for the ecosystem services market would also draw interest from corporations who are striving to achieve environmental, social, and governance (ESG) goals.
Forests are a vital step to clean water in the U.S. South. The work that Keeping Forests and its partners are doing will lay the foundation for Southern forest conservation for decades to come.
