In the 1960s, in response to new concerns about the impacts of a burgeoning timber industry, researchers Cortland Young, Jr. and Ralph Klaiwitter set up gauged weirs in the Santee’s streams and weather stations on the watersheds draining these streams to study the effects of forest management activities on the soils and waters of the Coastal Plain. Researchers and technicians have recorded data in the Santee—with some significant breaks—since 1964.

The Santee contains four gauged watersheds of different sizes. Young and Klaiwitter began their first longterm hydrologic observations in 1964, using the four watersheds to study soil moisture dynamics and runoff processes, as well as the effects of different types of land management practices such as understory eradication (through prescribed burning), clearcutting, thinnings, and constructing drainage and impoundments.

Though not much was published from data measured between1964 to 1982 on these experimental watersheds, the work of Young and Klaiwitter was fundamental in documenting a hydrology altogether different from mountain watersheds.

“In the mountains, water moves fast down steep slopes, but in coastal areas, water moves in a slow, diffuse way,” says Carl Trettin, team leader for the research unit at Santee. “This means that Coastal Plain rivers carry much less sediment, and the riparian zone is much wider, so much more sediment is captured before it can enter the stream. This also means greater potential for mitigating nutrients such as nitrogen because the water is moving slow enough for the denitrifying bacteria to do their job.”

These differences in waterflow, water balance, and pollutant cycling processes between mountain and coastal landscapes underscore the importance of the long-term data collected from the Santee weirs and rain gauges, especially now, as changing land uses put new pressure on water sources in the Coastal Plain.

After 1982, there were no Forest Service hydrologists around to analyze data from the weirs and rain gauges on the Santee. Fortunately, technicians on the site steadily kept records over the years (except from 1982 until after Hurricane Hugo in 1989) from both weirs and weather stations, storing them in whatever format was available at the time—tape, floppy discs, and often on paper.

The Charleston unit finally got another research hydrologist, Devendra Amatya, in 2002. With urban development fast encroaching on the Francis Marion, pushing water-quality issues to the forefront, Amatya began bringing together a wide range of cooperators interested in using science to ensure water quality and quantity in the Charleston area. In 2004, he started a research initiative focused on the Turkey Creek watershed in the Francis Marion with partners from colleges and universities, private industries, and State and Federal agencies joining SRS scientists in studies of the urbanizing landscape in relation to water quality.

One of the gauged weirs set up more than 40 years ago on the Turkey Creek watershed has been revived to provide the long-term baseline data that will help SRS scientists and regional planners look at the effects of land management and climate on the poorly drained watersheds of the Coastal Plain. The first task of the Turkey Creek initiative was to resume hydrologic monitoring of streamflow and climatic data, followed by waterquality sampling and analysis of historic data. Researchers need to understand more about the cumulative effects of forest management activities such as prescribed fire on wetlands, Amatya says. Turkey Creek, sitting on the edge of the national forest, also presents a unique opportunity as a baseline reference to look at the effects of urbanization on water quantity and quality as development creeps closer and more nearby residents use public lands for recreation.

No matter what happens, the real challenge, Amatya says, is to not let new threats—from population growth to climate change—catch scientists and leaders off guard.

To head off that surprise, Amatya wants to take advantage of technological advances and broader coalitions to address issues that threaten forest health over everincreasing boundaries. Trettin and Amatya are working with JimVose from Coweeta as well as with Steve McNulty and Ge Sun, both with the SRS Southern Global Change Program, to understand more fully what happens to water as it moves from mountain headwaters through the Piedmont regions and into the Coastal Plain. The team is incorporating long-term data and historical hydrologic studies from Coweeta and Santee into computer models designed to help local officials across the South understand how population growth and climate change will affect water availability in the coming years.

“I can’t stress enough the value of data from sustained long-term Forest Service research,” says Trettin. “Now we’re poised to move forward with partners, using our long-term hydrologic data to measure new impacts on water and on the Coastal Plain—and at the same time, develop and test models that planners and managers need to make decisions.”