Increasing Flood Frequency and Alluvial Fan Management: Case Studies from Vermont
Evan Fitzgerald, CPESC, CFM
Fitzgerald Environmental Associates
Colchester, Vermont
Over the last several decades, the northeastern United States has experienced increased total precipitation, rainfall intensity, and frequency of moderate and large floods. In particular, the State of Vermont has been hit by several large floods, including Tropical Storm Irene in 2011, the Halloween Flood of 2019, and the Great Flood of 2023. Increased frequency of moderate and large floods has reactivated sediment-dominated geomorphic landforms, including wandering and braided systems, and alluvial fans. Active management has become increasingly necessary in these geomorphic landforms to mitigate conflicts around infrastructure, and stream and floodplain restoration professionals are being called on to design sediment management solutions to satisfy landowners and state and federal regulatory staff.
In this talk we present several case studies of alluvial fan management in Vermont. Mitigation measures explored in these projects include FEMA buyouts, removal and relocation of berms, floodplain, and flood chute restoration, and the development of long-term sediment management plans. Alluvial fan management and restoration in developed areas is an especially challenging task for river management professionals, and the messaging to landowners in these settings should reflect the reality of our changing climate and the need to create more space for water, sediment, and wood.
About Evan Fiztgerald, CPESC, CFM
Evan Fitzgerald is founder and Principal Hydrologist/Geomorphologist at Fitzgerald Environmental Associates. He has over 20 years of experience in the fields of applied hydrology and geomorphology, including extensive experience with the development of watershed and river corridor based restoration plans. He is deeply involved in flood recovery and flood resilience efforts on behalf of state and municipal clients throughout the Northeast. Evan is a Certified Professional in Erosion and Sediment Control (CPESC) and a Certified Floodplain Manager (CFM).