Abstract

This report contains analyses of low-flow data and tabulations of computed low-flow frequency for all stream sites in Georgia where suitable flow records have been collected. These include 134 continuous-record gaging stations and 102 partial-record gaging stations. Frequency records for gaging stations with short records have been adjusted where possible to more closely represent results that would have been obtained from longer records.

Variations in time and place of low-flow characteristics, per unit of drainage area, are demonstrated. Low flows for 7 consecutive days with a 10-year recurrence interval vary from 0 to more than 1.0 cubic feet per second per square mile [(ft³/s)/mi²)]. In the Blue Ridge province in the northern part of the State, unit low flows range from 0.3 to 0.8 (ft³/s)/mi²; in the Valley and Ridge province in the northwest they range from 0.05 to 0.4 (ft³/s)/mi²; and in the Piedmont province they range from 0.1 to 1.1 (ft³/s)/mi².

There is a contrast in unit rates of low flow between the upper zone of the Coastal Plain where most flows are high, and the lower zone where most flows are low. Flows in the upper zone are in the range of 0.1 to 1.1 (ft³/s)/mi², but in the lower zone only the largest streams have appreciable flow during low-flow periods.

First posted December 7, 2010