Methods for Estimating Magnitude and Frequency of Peak Flows for Natural Streams in Utah

Scientific Investigations Report 2007-5158

Prepared in cooperation with Utah Department of Transportation and the Utah Department of Natural Resources, Divisions of Water Rights and Water Resources
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Estimates of the magnitude and frequency of peak streamflows is critical for the safe and cost-effective design of hydraulic structures and stream crossings, and accurate delineation of flood plains. Engineers, planners, resource managers, and scientists need accurate estimates of peak-flow return frequencies for locations on streams with and without streamflow-gaging stations. The 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence-interval flows were estimated for 344 unregulated U.S. Geological Survey streamflow-gaging stations in Utah and nearby in bordering states. These data along with 23 basin and climatic characteristics computed for each station were used to develop regional peak-flow frequency and magnitude regression equations for 7 geohydrologic regions of Utah. These regression equations can be used to estimate the magnitude and frequency of peak flows for natural streams in Utah within the presented range of predictor variables. Uncertainty, presented as the average standard error of prediction, was computed for each developed equation. Equations developed using data from more than 35 gaging stations had standard errors of prediction that ranged from 35 to 108 percent, and errors for equations developed using data from less than 35 gaging stations ranged from 50 to 357 percent.

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Additional publication details

Publication type:
Publication Subtype:
USGS Numbered Series
Methods for Estimating Magnitude and Frequency of Peak Flows for Natural Streams in Utah
Series title:
Scientific Investigations Report
Series number:
Version 4.0, Revised Mar 2008
Year Published:
Geological Survey (U.S.)
Contributing office(s):
Utah Water Science Center
iv, 28 p.