A $2.5 million grant from the U.S. Department of Energy is helping UNM researchers concentrate on the hydrological health of headwater streams, the small but complex rivulets that knit together to feed rivers. “Headwater stream networks are vital to downstream ecosystems,” said Alex Webster, a UNM assistant professor and principal investigator on the project, which is based in UNM’s Center for the Advancement of Spatial Informatics Research and Education.

The group is concentrating on five very different headwater stream networks spread across the continental U.S. — the Upper Santa Fe River Watershed in New Mexico, which drains into the Santa Fe River; the Dog Creek Watershed in Nevada, which drains into the Truckee River; South Sandy Creek in Alabama, which drains into the Black Warrior River; Richland Creek in Arkansas, which drains into the White River Basin; and the Lamprey River in New Hampshire, which drains into the Great Bay Estuary.

“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. “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.”

The first stage of the project, involving a group of researchers at The University of Oklahoma, will include hydrologic modeling to predict what entire watershed stream networks are doing based on observations of waterflow, precipitation and other factors. The second stage includes understanding the spatial structure of each watershed in terms of how it influences water quality and quantity. The third and final part of the project will look at how all this changes throughout time in response to changing patterns of precipitation and drought.

“As the stream network dries up, we get less water downstream, but the important question is, if something happens in one part of the watershed, is that going to have a bigger impact compared to if it happened in other parts of the watershed? That sort of understanding will be incredibly helpful for water management,” Webster said.

The group of researchers will also work in collaboration with Oak Ridge National Laboratory to compare and contrast watershed findings to one being studied in Tennessee. Researchers say this study will impact future research and will provide essential infrastructure investment that will enable states to better monitor and manage the water quality and quantity that headwater streams export to downstream waters.