Effects of Upstream River Flow Regulation on the Annual Low Flow Magnitude in the Savannah River at Augusta, Georgia, USA

摘要

The present paper investigates the effects of flow regulation on low flow conditionsin the Savannah River at Augusta, GA before and after the construction of majordams and reservoirs. The Savannah River flow upstream of Augusta, GA is regulatedby the operation of three large federal multipurpose projects: Hartwell Dam, RichardB. Russell Dam, and J. Strom Thurmond (also known as Clarks Hill) Dam. Duringlow-flow periods, the operation of the dams is controlled by the drought contingencyplan of the Savannah River basin. Analyses of low flow statistics at the Augustawater level gauge indicate that trends in the low flow volumes and frequencies aresignificantly modified after the construction of the dams. Although water level datacollected before and after the construction of the dams show homogeneous properties,the data show considerable heterogeneity because of flow regulation when the fulldata record is considered. Low flow statistics for the period after the construction ofall three dams show the Log Pearson Type 3 distribution to be the most suitable. Flowdistribution also shows a considerable increase in annual minimum daily-mean flowrate compared to that prior to the construction of the dams.