StreamStats for California was developed in cooperation with the Federal Emergency Management Agency, the U.S. Army Corps of Engineers, and the U.S. Forest Service.
California StreamStats provides peak-flow statistics with annual exceedance probabilities of 50, 20, 10, 4, 2, 1, 0.5, and 0.2 percent. These peak flows have recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year floods. Two reports document the regression equations used in StreamStats for estimating peak flows. The report by Gotvald and others (2012) presents equations applicable throughout California except for the southern desert region. Equations from the report by Thomas and others (1997) are available for southern desert region of California. These reports present the regression equations used to estimate peak flows, document the errors associated with the estimates, and describe the methods used to develop the equations and to measure the basin characteristics used in the equations.
- Gotvald, A.J., Barth, N.A., Veilleux, A.G., and Parrett, Charles, 2012, Methods for determining magnitude and frequency of floods in California, based on data through water year 2006: U.S. Geological Survey Scientific Investigations Report 2012–5113, 38 p., 1 pl.
- Thomas, B.E., Hjalmarson, H.W., and Waltemeyer, S.D., 1997, Methods for Estimating Magnitude and Frequency of Floods in the Southwestern United States: U.S. Geological Survey Water-Supply Paper 2433, 195 p.
Thomas and others (1997) did not develop a regression equation for the 0.2 percent probability peak flow. In areas where these equations are used, the 0.2 percent probability peak flow is determined by extrapolating the frequency curve based on a method described on page 14 in the report:
Click on this link to obtain general information on the California application, as well as specific sources and computation methods for basin characteristics.
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Methods for determining magnitude and frequency of floods in California, based on data through water year 2006
The National Streamflow Statistics Program: A Computer Program for Estimating Streamflow Statistics for Ungaged Sites
Methods for estimating magnitude and frequency of floods in the southwestern United States
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- Publications
Methods for determining magnitude and frequency of floods in California, based on data through water year 2006
Methods for estimating the magnitude and frequency of floods in California that are not substantially affected by regulation or diversions have been updated. Annual peak-flow data through water year 2006 were analyzed for 771 streamflow-gaging stations (streamgages) in California having 10 or more years of data. Flood-frequency estimates were computed for the streamgages by using the expected momeAuthorsAnthony J. Gotvald, Nancy A. Barth, Andrea G. Veilleux, Charles ParrettThe National Streamflow Statistics Program: A Computer Program for Estimating Streamflow Statistics for Ungaged Sites
The National Streamflow Statistics (NSS) Program is a computer program that should be useful to engineers, hydrologists, and others for planning, management, and design applications. NSS compiles all current U.S. Geological Survey (USGS) regional regression equations for estimating streamflow statistics at ungaged sites in an easy-to-use interface that operates on computers with Microsoft WindowsAuthorsKernell G. Ries(compiler), J. B. With sections by Atkins, P.R. Hummel, Matthew J. Gray, R. Dusenbury, M.E. Jennings, W.H. Kirby, H. C. Riggs, V.B. Sauer, W.O. ThomasMethods for estimating magnitude and frequency of floods in the southwestern United States
Methods were developed for estimating magnitude and frequency of floods at gaged and ungaged sites in the Southwestern United States. Estimating equations for ungaged sites were developed by transferring information from gaged to ungaged sites using multiple regression and a hybrid method developed during this study. The methods and analysis are described, and information from more than 1,300 gageAuthorsBlakemore E. Thomas, H. W. Hjalmarson, Scott D. Waltemeyer - Partners