The Town of Lyndon, Vermont, is situated at the confluence of the multiple branches of the Passumpsic River and Millers Run. Significant development has occurred in the floodplain, both reducing floodplain function and increasing risk to infrastructure. Today, flooding occurs routinely in Lyndon, covering major intersections and roadways, and, in the worst cases, damaging homes and businesses. The community hired water resource engineers SLR Consulting to examine possible solutions to reduce flood damage and develop flood mitigation strategies. Whiteout Solutions was contracted by SLR Consulting to collect topobathymetric data to support the hydraulic river model used to test mitigation solutions.

Objective: Generate high-resolution topographic and bathymetric maps of the river corridor and floodplain in Lyndon, Vermont. SLR Consulting is using the data to a develop high-resolution 2D hydraulic model, to test and validate the effectiveness of various flood mitigation strategies.

Challenge: High-resolution bathymetric data is crucial for developing accurate models, but most engineering firms rely on traditional wet surveys, remote-controlled boats with sonar, or publicly available bathymetric data. These methods can create dangerous or high-risk survey conditions, require more resources and longer project time frames, and typically result in lower-resolution models with less confidence in the final designs. Publicly available data typically does not extend below the water surface.