| This study measured the ability of a stormwater detention basin and associated floodplain to remove sediment from stormwater runoff. Primary constituents measured were: flow, total suspended solids (TSS), the inorganic fraction of TSS, fine particle concentration (FSP) for particles ≤16 µm, and turbidity. Fine particles are the primary pollutant of concern for the Lake Tahoe basin because they decrease the optical clarity of the lake. The study was performed at Cattlemans detention basin, a constructed stormwater facility, in South Lake Tahoe, CA. Samples were taken at three points: the inflow and overflow of the basin, and the bottom of the portion of the floodplain that the basin overflows into. Eight storm and snowmelt events were sampled during 2011 and 2012. The basin showed significant reductions, for a level of significance α = 0.05, for concentrations of TSS, FSP and turbidity. The floodplain often acts as a load source and did not significantly reduce concentrations for any constituents. Median inflow, basin outflow and floodplain event mean concentrations were: TSS (mg/L): 54.4, 9.27, 21.6; FSP (... |
