Evaluation of Flood Control and Treatment of Total Suspended Solids by Dry Detention Basins in Greenville, NC

Abstract

Urban development has increased the total impervious area in human settlements, which has disrupted natural hydrology resulting in increased nuisance flooding and water quality degradation from storms. Over the past several decades, stormwater management has become an integral component of urban planning to mitigate damage through use of stormwater control measures (SCMs). Dry detention basins (DDBs) are a commonly used SCM designed to mitigate peak flow volumes by capturing and storing runoff that is slowly released into the existing stormwater infrastructure. The goal of this study was to characterize functionality and evaluate flood control and treatment of total suspended solids (TSS) by 4 DDBs located in Greenville, NC. Of the 4 DDBs, 2 are within potentially underserved communities according to NC DEQ designation. Onset HOBO pressure transducers were installed in the Winter of 2023 to measure water levels during storms. Water level data will be used to evaluate storm hydrology to assess flood control by DDBs. Additionally, samples were collected from the inlet and outlet of DDBs for a total of three storms to assess the reduction of TSS concentration. Discharge entering and exiting were also measured during the storms to estimate mass inputs and exports of TSS.