Concurrent Session: Wetlands and management in a changing climate
11:00 AM - 12:00 PM Thu
CO-AUTHOR: Jaameson Loesch, Merjent
TITLE: Michigan dam disaster: Evaluating wetland extent on the bottomlands of a drained lake system
ABSTRACT: In May 2020, an unprecedented rainfall event and associated heavy flooding resulted in the complete failure of the Edenville and Sanford Dams in Midland and Gladwin Counties, Michigan. As a result of this natural disaster, a series of four impounded lakes totaling thousands of acres were drained. This has led to the continued draining and degradation of adjacent wetlands due to changed hydrology and the formation of new wetlands on the disturbed lake bottomlands. The amount of wetland present on the current lake bottomlands requires evaluation in order to satisfy regulatory requirements to rebuild the dams and restore the lake system, as required under the current legal lake level order. Merjent, in coordination with state regulators, developed an approach that combined geospatial analysis and field verification techniques to determine an estimate of quantity, quality, and type of wetlands that are currently forming on the bottomlands. This review represents a number of challenges as all three parameters of typical wetland delineation methodology are considered both naturally problematic and significantly disturbed. Merjent reviewed a series of post-flood, drone-captured imagery spanning several months. Using geospatial tools, we classified signature types based on imagery differences. Next, Merjent’s field biologists spot-checked these signatures by collecting soil, vegetation, and hydrology data at a series of monitoring points across the bottomlands. Using data, we revised the classified signatures and developed a detailed wetland and vegetation community type map. This information has since been provided to the regulators for further discussion related to project permitting.
BIO: Robb Roos is a project manager for an environmental consulting firm. He has worked in the fields of wetland and restoration ecology for more than ten years. Robb leads wetland delineation survey field teams on projects throughout the Midwest and co-instructs wetland delineation trainings. He is currently certified as a Wetland Professional by the Society of Wetland Scientists.