Low-flow and flow duration of Tennessee streams

Low-flow frequency and duration data are presented to define variations of the low flow of Tennessee streams both in time and place. Analysis has been made of 204 continuous record stations, both regulated and unregulated and 651 partial-record stations operated either by the U.S. Geological Survey or Tennessee Valley Authority through the 1975 water year. Flow duration and frequency data have been tabulated for the continuous record sites using the digital computer and graphical methods. Frequency data only is presented for partial-record sites computed in most cases by comparing several discharge measurements at the site with concurrent daily mean flow for an appropriate gaging station. Flow duration data can be used to define a flow duration curve, with the slope at points on that curve used to establish the dependability of the stream to sustain a particular flow. Low-flow frequency data are presented to predict the probability that a specified flow or lesser flow will recur through time. (USGS)