Rachael Messenger-Lehmann receives 2025 John Parish Memorial Graduate Scholarship
The Water Institute is pleased to announce that Rachael Messenger-Lehmann has been awarded the 2025 John Parish Memorial Graduate Scholarship. This prestigious award recognizes outstanding research in fluvial geomorphology—the study of rivers, their processes, and how they influence the landscape.
A passion for rivers
Rachael completed her undergraduate degree in Environmental Engineering with a specialization in Hydrology at the University of Waterloo. While initially exploring various environmental disciplines, she quickly discovered her passion for rivers.
"I knew very quickly that learning and working with water systems—especially rivers—was where I wanted to be," said Rachael. "I took every river and wetlands course I could and sought out any co-op job in fluvial geomorphology and river restoration."
As she approached the end of her degree, Rachael considered graduate studies but was determined to find the right project—one she could truly be passionate about. Just as she was preparing to enter the workforce, Water Institute member Dr. Bruce MacVicar, now her research supervisor, reached out with the perfect opportunity.
Pioneering research in river corridor management
Rachael’s research explores how to maintain and create space for rivers in landscapes affected by human activities. Across the globe, riparian zones—the critical buffers between land and water—are under threat from urbanization, agriculture, and forestry. These natural buffers play a key role in maintaining water quality, ecosystem resilience, and habitat diversity.
"My research focuses on identifying the optimal riparian buffer width needed to preserve a river’s health and natural morphological functions," Rachael explained. "The goal is to influence river management practices and highlight riparian buffers as nature-based solutions for sustainable watershed management."
A groundbreaking experimental approach
A key aspect of Rachael’s research is a laboratory study using a scaled model of the Bow River. The experiment features an innovative flume setup measuring 2 metres wide and 14 metres long, simulating sediment transport and bank erosion under controlled conditions. A novel element of the study is the use of alfalfa as a proxy for floodplain vegetation, mimicking how plant roots stabilize soil and influence river dynamics. This marks one of the first experiments of its kind in Canada, contributing to global advancements in riverine research.
Photo L to R: Sean Ferguson (National Research Council Canada), Ivana Vouk (National Research Council Canada), Rachael, and Violet French (Environmental Engineering Coop student). Rachael describing the observed flow-sediment-vegetation interactions to visitors from the National Research Council (NRC) as part of the experiment in the Sandee River Table in the University of Waterloo Hydraulics Lab. The research is supporting the development and application of Nature-Based Solutions to river restoration in Canada and was funded by NRC’s Climate Resilient Built Environment Initiative, in support of delivering the Government of Canada’s Adaptation Action Plan, towards achieving commitments under the National Adaptation Strategy.
Collaboration and impact
Rachael’s research is a highly collaborative effort involving the City of Calgary, the National Research Council of Canada, and the University of Ottawa. This partnership has helped secure a $150K Alliance Advantage grant, supporting the development of evidence-based floodplain management guidelines.
Reflecting on receiving the John Parish Memorial Graduate Scholarship, Rachael shared:
"Being recognized by the family and friends of John Parish—people who share my passion for rivers—is such an honour. Thanks to their generosity, I’ll be able to share my research at conferences and events to help protect rivers more effectively."
She also spoke about the impact of the award on her academic journey: "Research is a long process, and at times, it’s hard to know if you’re on the right track. Being recognized with this award helps remind me of the importance of my research and inspires me to work even harder!”
Dr. Bruce MacVicar, Rachael’s supervisor, commended her contributions: "Rachael’s work is groundbreaking in its approach to modeling river dynamics in a laboratory setting. I never dreamed we would spend so much time thinking about the growth and root strength of alfalfa, but this is where the research has led us. Her results are surprisingly profound in their implications for the benefits of floodplains for river function. This scholarship is a testament to her outstanding contributions to the field."
We extend our warmest congratulations to Rachael on this well-deserved recognition. Her research has the potential to transform river management practices and contribute valuable insights to sustainable watershed planning. We look forward to seeing the impact of her work in the years to come.
