The Muddy Side of Science: Meet Christy Leonard

By Lael Gilbert | October 21, 2022
Christy Leonard headshot
Christy Leonard, Post-doctoral researcher

Welcome to the Desert

Christy Leonard started her career on the muddy side of science. She had just completed an undergraduate degree in geology from the University of Vermont, and drove cross country to California for a position with the Army Corps of Engineers to work on flood protection projects in California’s Central Valley. She was surprised, in that state, by the vast stretches of desert, the excellent tacos, and by the cultural contrast of water management from what she had known growing up in the Midwest.

“The network of levees and dams in California’s Central Valley was unlike anything I had ever seen in Indiana. I couldn’t believe the massive amount of infrastructure needed for people to grow food, have water for their homes, and safely live in flood prone communities,” she said.

Christy Leonard working on the Yampa River.

Working for the first time for a major water resource agency in the arid west exposed her to the challenges and complexities of western water resource development. Growing up in a rural community in the Midwest, she was acutely aware of agricultural practices and norms, but water for irrigation in her home state of Indiana primarily came from the sky.

The experience changed the focus of her career … from geology to fluvial geomorphology, and from the geologic perspective of millions of years to more applied management questions that unfold over the relatively quick arc of decades. In 2015, she received a Masters Degree in Geography/Water Resources from the University of Wyoming, and continued to work for the Army Corps of Engineers until 2017, when she started her Ph.D. program at Utah State University.  Leonard realized the deep implications of water management decisions in the west, the complexity of the issues, and the importance of backing up solutions with science.

“I realized pretty quickly that if I wanted to have a voice in the solution, I needed an advanced degree … one that would allow me to develop critical thinking skills to break down the components of these intricate challenges and figure out which questions are important and worth pursuing, even if those questions have not been the traditional focus of managers.”

Faculty Advisor: Dr. Jack Schmidt
Research Area: Quantifying the magnitude of a sediment mass imbalance necessary to cause channel adjustment: What constitutes a big number?

Leonard's doctoral research was in the field of fluvial geomorphology---the study of river form and process---which is concerned with understanding a river's shape and behavior, especially as it relates to the movement of water and sediment. The shape of river channels and their floodplains is largely determined by how streamflow interacts with sediment as it is pushed through. The size and shape of the sediment, the flow of the water, management of dams, changes in nearby land, and natural disturbance like floods and storms can all change a river’s streamflow and the type of sediment that reaches the river. Predicting how a river channel will respond to changes is complex because all of these factors can magnify or level out each other.  Leonard's research helped to determine specific circumstances when a change in streamflow or sediment supply is likely to cause a change in the channel and floodplain.

Leonard’s research provided managers a framework to predict how changes in reservoir releases would impact endangered fish habitat and other river ecosystem resources. She worked with a system of sediment gages on the Green and Yampa Rivers in Dinosaur National Monument, Utah downstream of Flaming Gorge Dam. These gages project sound waves to measure the amount of sediment moving into and out of a river reach every 15-minutes, producing a mountain of data that managers use to determine whether sediment is being stored or eroded from the river, and what kind of dam operations cause those movements. Christy helped to link these data to changes in reservoir releases and endangered fish habitat. 

The questions she asked included – Is the sediment being measured as stored in the river causing the river channel to narrow? When should managers be concerned that the amount of sediment at the gages are a signal for damage to endangered fish habitat? How could they change reservoir releases to stop this from happening? Her work closed a research gap by directly connecting the measured change in sediment storage to on-the-ground changes in the river’s shape and form. She explored how much sediment storage or erosion needed to happen before detrimental changes in aquatic habitat actually took place in real life. 

Her Work at CCRS

Working with the Center for Colorado River Studies has lots of advantages, said Leonard. It gives her the space to work to think outside the box, to find unconventional solutions to applied problems. Although she has resources for mentoring, she doesn’t have anyone directly dictating the questions that need answers, or how the results should fit in a neatly tied package.

“It’s a hard prospect not to be instructed on a direct deliverable to a question that has already been proposed, but it is ultimately an advantage,” she said. “It forces me to consider which questions are important and understand how answering those questions will inform innovative solutions to applied problems.”

Her experience at CCRS has also allowed her remarkable opportunities for networking and building partnerships. She has worked with the USGS Grand Canyon Monitoring and Research Center, the Upper Colorado River Endangered Fish Recovery Program, the National Park Service, the Bureau of Reclamation, and others to stay engaged in management applications of her research.