Skip Links

USGS - science for a changing world

Open-File Report 2010–1305

Prepared in cooperation with the South Carolina Department of Health and Environmental Control

Low-Flow Frequency and Flow Duration of Selected South Carolina Streams in the Broad River Basin through March 2008

By Wladmir B. Guimaraes and Toby D. Feaster

Thumbnail image of report cover


In 2008, the U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, initiated a study to update low-flow statistics at continuous-record streamgaging stations operated by the U.S. Geological Survey in South Carolina. This report presents the low-flow statistics for 23 selected streamgaging stations in the Broad River basin in South Carolina, and includes flow durations of 5-, 10-, 25-, 50-, 75-, 90-, and 95-percent probability of exceedance and the annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day mean flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years, depending on the length of record available at the streamgaging station. The low-flow statistics were computed from records available through March 31, 2008. In addition, flow duration information is presented for one streamgaging station 021556525, Pacolet River below Lake Blalock near Cowpens, SC, where recurrence interval computations were not appropriate.

Of the 23 streamgaging stations for which recurrence interval computations were made, 14 had low-flow statistics that were published in previous U.S. Geological Survey reports. A comparison of the low-flow statistics for the minimum mean flow for a 7-consecutive-day period with a 10-year recurrence interval (7Q10) from this study with the most recently published values indicated that 8 of the 14 streamgaging stations had values that were within plus or minus 25 percent of the previous value. Ten of the 14 streamgaging stations had negative percent differences indicating the low-flow statistic had decreased since the previous study, and 4 streamgaging stations had positive percent differences indicating that the low-flow statistic had increased since the previous study. The low-flow statistics are influenced by length of record, hydrologic regime under which the record was collected, techniques used to do the analysis, and other changes, such as urbanization, diversions, and so on, that may have occurred in the basin.

First posted December 20, 2010

For additional information contact:
USGS South Carolina Water Science Center
Stephenson Center,Suite 129
720 Gracern Road
Columbia, SC 29210–7651
phone: 803–750–6100

Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Guimaraes, W.B., and Feaster, T.D., 2010, Low-flow frequency and flow duration of selected South Carolina streams in the Broad River basin through March 2008: U.S. Geological Survey Open-File Report 2010–1305, 47 p.




Purpose and Scope

Previous Studies

Description of the Study Area

Low-Flow Statistics

Analytical Approach

Quality Assurance and Quality Control


Frequency Analysis

Record-Extension Technique

Partial-Record Type Analysis

Flow-Duration Analysis

Considerations for Accuracy of Low-Flow Statistics

Comparison with Previously Published Low-Flow Statistics


Selected References

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: USGS Publications Team
Page Last Modified: Wednesday, 07-Dec-2016 23:00:50 EST