HISTORIC FLOODING OF THE STONES RIVER – SHARP SPRINGS PARK, SMYRNA, TENNESSEE

In May 2010, the greater Nashville area received upwards of 13 inches of rain over a two-day period, resulting in devastating flooding that also took the lives of 21 individuals. Sharp Springs Park in Smyrna, Tennessee is located along the East Fork of the Stones River and was one natural area inundated by this flooding event. Situated in a carbonate karst bedrock, the park contains four isolated sinkhole lakes with no channelized inflow or outflow. For detrital sediments to reach these closed-basin lakes, floodwaters must travel overland from the Stones River, as was observed in the spring of 2010. With known instances of flooding inundating these lakes, the sediments from this location could record large flood events over the last several hundred to thousand years, providing information to better inform residents of Rutherford County about regional flood recurrence intervals.

As such, short soft-sediment gravity cores were collected in the spring and summer of 2024 for sedimentologic and geochemical characterization to investigate these questions. We hypothesize that the sinkhole lakes at Sharp Springs Park record instances of major flooding of the East Fork of the Stones River and that layers deposited due to historic flooding will be characterized as having larger-grained sediments that exhibit a higher magnetic susceptibility than the sediments that constitute normal fine-grained, organic-rich deposition within these sinkhole lakes. To identify the 2010 flooding event and assess these cores for other historical flood layers, sediment proxy data such as grain size, loss-on-ignition, and magnetic susceptibility were developed. An age-depth model was assigned using ²¹⁰Pb and ¹⁴C ages. This project aims to constrain the known frequency of flooding within this watershed from lacustrine sediment cores, to extend our knowledge of hydroclimate variability in Central Tennessee in the recent past.