As climate change fuels more intense and frequent storms, strengthening flood mitigation strategies has become a top priority. Lives, agriculture, and critical infrastructure are at increasing risk, particularly in downstream communities where effective flood resilience is essential. A new study from the University of Vermont (UVM) sheds light on a powerful yet underutilized natural ally in this fight: floodplains.
Floodplains the low-lying land flanking rivers and streams act as nature’s shock absorbers. By temporarily storing excess water during floods, they reduce flood peaks, slow water velocity, and limit erosion in a process called attenuation. But not all floodplains work the same way. The latest research published in the Journal of Geophysical Research: Earth Surface introduces an innovative method to identify and classify floodplains based on how effectively they can reduce flood impacts.
Dr. Rebecca Diehl, the study’s lead author and a research associate professor at UVM “This approach allows us to understand how different floodplain types can slow floodwaters and reduce damage It fills a major gap in current flood prediction and watershed management models, which often overlook floodplain function.”
How Terrain Shapes Flood Mitigation
The study relies on widely available topographic data to detect landscape features along rivers that are likely to slow floodwaters. These features are then grouped by their shape and size to reveal how they influence flood behaviour. Researchers tested the method across Vermont’s Lake Champlain Basin a diverse area ranging from mountain terrain to low-lying valleys and identified six distinct floodplain types, each with different abilities to store and decelerate floodwaters.
This new Hydraulic Floodplain Classification system provides a scalable tool that can be applied well beyond Vermont, helping water managers in different regions make more informed decisions about where and how to manage flood risks.
Real-World Impact on Watershed Management and Planning
By pinpointing which floodplains offer the greatest potential to reduce flooding, the study equips decision-makers with critical insights for restoration projects. For example, it can help prioritize where to reconnect floodplains, remove outdated infrastructure, or reintroduce native vegetation to maximize natural flood defences.
Importantly, the classification system also serves as a clear communication tool. “This helps bridge the gap between science and policy,” Diehl noted. “It gives communities and planners a data-backed way to evaluate whether actions like upstream watershed restoration will truly help reduce flood risks.”
Better Data, Better Forecasts, Safer Communities
The study’s implications go beyond restoration. It also calls for a rethinking of how flood forecasting models represent the landscape. Many large-scale models currently lack detailed information about river-floodplain interactions, leading to inaccurate flood warnings that leave communities vulnerable.
By incorporating the Hydraulic Floodplain Classification into forecasting systems, water managers can improve flood modelling and enhance early warning capabilities. This is especially crucial as extreme weather events become more unpredictable and severe.
The findings also highlight the broader environmental benefits of protecting natural floodplains. In addition to slowing floodwaters, floodplains filter out sediments and pollutants, improve water quality, and support ecosystem health.
As the planet warms and flood threats mount, this research offers a hopeful path forward. With better data and a renewed focus on nature-based solutions, communities can build resilience not just to the next storm but to a changing climate.