Up to 35% of headwater streams, which make up the vast majority of global river miles, are intermittent, yet the importance of these systems is not well understood due to the recurring wetting and drying cycles. 

Arkansas researcher Shannon Speir is part of a multi-state team working to learn more about how these small streams can affect lakes and reservoirs that supply our drinking water. The research may have implications for guidance on Clean Water Act regulations and monitoring the primary source of drinking water in Northwest Arkansas in response to climate change.

Speir is an assistant professor of water quality in the Crop, Soil and Environmental Sciences Department for the Dale Bumpers College of Agricultural, Food and Life Sciences at the U of A and the Arkansas Agricultural Experiment Station, the research arm of the U of A System Division of Agriculture. 

With her team of student researchers, they will study the movement of nutrients, such as nitrogen and phosphorus, in Brush Creek, a tributary of the Beaver Lake watershed. It is part of a larger study across many states that is funded by the U.S. Department of Energy to learn more about the impact headwater streams have on major bodies of surface water.

"We are looking at when the tiny streams go dry at the top and then rewet, and dry and rewet, how that affects nutrient transport downstream," Speir said. 

Speir said there is potential for headwaters to be major transporters of nutrients and sediments throughout the year. Intermittent headwater streams tend to flow after heavy rains and carry nutrients downstream. An overabundance of nutrients like nitrogen and phosphorus, Speir said, can cause eutrophication, which increases the amount of plant and algae growth and decreases the amount of available oxygen for fish.

She is teaming up with water quality scientists in five other states to expand the knowledge of how these intermittent stream networks that dry up and fill back up after storms can determine the amount and quality of water that ends up downstream.

"If we can understand how conservation in one part of the watershed might affect the signal downstream, we can start to understand how much conservation we need to make changes downstream," Speir said. "This grant provides an underlying foundational science backbone supporting more applied work."

Headwaters Researchers

The two-year research project begins this month and is supported by a $2.5 million grant awarded by the Department of Energy through its Established Program to Stimulate Competitive Research, or EPSCoR, program. Speir's lab will receive about $330,000 to purchase new water quality sensors and conduct research on Brush Creek in the Beaver Lake watershed. She said sensors will be "nested" in public access areas of the creek.

The grant proposal was submitted through the University of New Mexico's Center for Advancement of Spatial Informatics Research and Education. The award is part of a $33 million Department of Energy effort that supports 14 research projects covering a range of research topics, from fundamental science topics to efforts in fusion energy, climate and ecosystem modeling, grid integration, wind energy and sensors for energy conversion.

Alex Webster, assistant professor in the University of New Mexico's Biology Department, is the principal investigator on the project. Her team in New Mexico will study the headwaters of the Santa Fe River and serve as the hub for project data analyses.

"Historically, we treated these headwater watersheds like black boxes. We tend to care about how much water comes out of them and the quality of that water, but not so much about the reasons why," Webster said in a University of New Mexico news release. "There is a lot going on in them; they are changing very quickly because they are very sensitive to climate change, including to changes in snowpack and because that's where streams tend to dry up first."

Co-principal investigators and research areas include:

• Arial Shogren, University of Alabama Biological Sciences Department; headwaters of the Black Warrior River
• Joanna Blaszczak, University of Nevada, Reno's Natural Resources and Environmental Science Department; headwaters of the Truckee River
• Adam Wymore, University of New Hampshire's College of Life Sciences and Agriculture; headwaters of the Great Bay Estuary
• Yang Hong, University of Oklahoma's College of Engineering; hydrologic modeling

Speir said hydrologic modeling, using computer simulations of watershed reactions, will be the first stage of the study, and this is a specialty of Hong's team at the University of Oklahoma. The first stage of the study calls for simulating the processes of entire watershed stream networks based on observations of water flow, precipitation and other factors. 

The second stage includes understanding each watershed's "spatial structure," or how it influences water quality and quantity. The third phase will look at changes over time in response to changing precipitation and drought patterns. Project researchers will also collaborate with the Department of Energy's Oak Ridge National Laboratory to compare findings to a Tennessee watershed.

With more knowledge of headwater processes, the study could help states better monitor and manage water quality, water quantity and ecosystem responses to a changing climate, Speir said. For example, it could help water treatment facilities better predict what's coming into the system and adjust their process accordingly.

Speir's team on the project includes Kathleen Cutting, a water quality science master's degree student, and program associate Alana Strauss, both with the Crop, Soil and Environmental Sciences Department. Her team will conduct "synoptic sampling campaigns," where they take a snapshot sampling in one day of 20 sites across the watershed. 

To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. 

About the Division of Agriculture: The University of Arkansas System Division of Agriculture's mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation's historic land grant education system. The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on five system campuses. The University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.