StreamStats in South Carolina
StreamStats is available for South Carolina on a limited basis. Currently, users can select or enter a stream location, delineate the drainage basin for the selected location, and determine the drainage area and the percentages of the drainage area that is in each of the hydrologic regions of South Carolina, as described in the report:
- Feaster, T.D., Gotvald, A.J., and Weaver, J.C., 2009, Magnitude and frequency of rural floods in the Southeastern United States, 2006—Volume 3, South Carolina: U.S. Geological Survey Scientific Investigations Report 2009–5156, 226 p.
The above report contains regional regression equations for estimating peak-flow estimates at the 50-, 20-, 10, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities at any user selected stream location. These equations are not implemented in StreamStats; however, a spreadsheet program that can be used to insert the drainage area and hydrologic region percentages from StreamStats and obtain the peak-flow estimates is available at http://pubs.usgs.gov/sir/2009/5043/downloads/Application_of_Methods_Tool_version_1_3.xls.
StreamStats for South Carolina is in the development stage. This application was implemented on a temporary basis with limited functionality in response to the urgent need for a simple method for obtaining peak-flow estimates required to design bridges, culverts and other structures that were damaged as a result of the flooding that occurred in that State during October, 2015. Data used to delineate drainage basins for this application were provided by ESRI, Inc., and are a modified version of the NHDPlus version 2 dataset, which was created cooperatively by the U.S. Environmental Protection Agency and the U.S. Geological Survey. The NHDPlus version 2 dataset relies on 1:24,000-scale hydrography and digital elevation data at approximately 30-meter grid spacing. Delineations should be checked carefully for accuracy, particularly in flat areas. The U.S. Geological Survey, in cooperation with the South Carolina Department of Transportation, is working with lidar-based data to prepare datasets for use in StreamStats that promise more accurate delineations than those afforded by this current application. Project completion is expected in 2018.
StreamStats users should refer to the above report by Feaster and others (2009) to obtain the latest approved estimates of peak-flow statistics for streamgaging stations in South Carolina, as the data from that report are not yet available from StreamStats. Also, the USGS has released a report that provides preliminary peak stages and streamflows that occurred during the October 1-5, 2015 flooding at selected USGS streamgaging stations for the South Carolina. Data from this report also are not available from StreamStats. The report is:
- Feaster, T.D., Shelton, J.M., and Robbins, J.C., 2015, Preliminary peak stage and streamflow data at selected USGS streamgaging stations for the South Carolina flood of October 2015: U.S. Geological Survey Open-File Report 2015–1201, 19 p.
StreamStats was developed for South Carolina in cooperation with the South Carolina Department of Transportation.