Last week, N-EWN researcher Dr. Rod Lammers presented his research as part of the N-EWN initiative at the 20th Annual Meeting of the American Ecological Engineering Society. His presentation featured work by himself, Dr. Matthew Chambers, Dr. Matthew V. Bilskie and Dr. Brian P. Bledsoe, and was titled “Engineering With Nature: Using levee setbacks to reduce flood stage.”
To learn more about his presentation, read the abstract below:
The Network for Engineering with Nature (N-EWN) is a community of researchers, practitioners, and educators who are developing ecological engineering practices to address today’s infrastructure challenges and deliver economic, environmental, and social benefits. One aim of N-EWN is to explore nature-based solutions to address riverine and coastal flooding issues. This presentation will describe one such solution: using levee setbacks to reconnect rivers with their floodplains, thereby reducing flood stage and risk. Levees are built to protect development in floodplains from inundation. However, levees constrict rivers, reduce natural channel-floodplain interaction, and can increase flood risk up and downstream. We use hydraulic modeling of several theoretical rivers to explore how different sizes and configurations of levee setbacks can reduce flood stage throughout the river system by allowing for natural flood attenuation on floodplains. Results show that levee setbacks can significantly reduce flood stages for a variety of flood sizes. Stage reductions are greatest within the region of the levee setback, but also extend significantly up and downstream. Benefits generally increase with more reconnected floodplain area; however, the spatial configuration of levee setbacks affects the location and size of the flood stage reductions. These results can help guide the prioritization of levee setbacks and serve as an initial step in creating design guidelines for optimizing the hydraulic benefits of these projects.