274-5 Impacts of Hurricane Helene on Southern Appalachian Mountain Wetlands

Session: Advances in Ecohydrogeology

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Abstract:

In September 2024, Hurricane Helene—and a precursor rain event (PRE)—brought up to 30 inches of rain over three days, wind gusts over 100 mph, more than 2000 landslides, and record flooding across Western North Carolina. Several “priority” wetland sites (identified as such by the Mountain Bogs National Wildlife Refuge) were in the path of Helene’s destruction and have also been part of a long-term hydrologic monitoring program. This presentation will include hydrologic data (stormwater depths and durations) from six wetlands in Henderson County (NC), photos taken in the days and weeks following the storm, and observations over the past year as the sites recover.

Southern Appalachian wetlands are home to a variety of federally- and state-listed species. They are fed by groundwater (fens), but are often located at the base of slopes and/or along the edges of rivers and streams and subject to flooding from above or below. Four of the six Henderson County sites began flooding from upstream inlets during the precursor rain event (PRE), while two of the sites weren’t inundated until their outflows were backed up following Helene. One site had two distinct stormwater peaks for the PRE and Helene rainfalls. Peak flooding depths ranged from 0.48ft (0.15m) to 10.3ft (3.1m), and the time for water levels to recede to baseflow conditions ranged from 19 hours to 8 days.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10276

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