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Arizona StreamStats

StreamStats was developed for Arizona in cooperation with the Bureau of Reclamation, the Flood Control District of Maricopa County, Greenlee County, the Flood Control District of Mohave County, the U.S. Forest Service, the Pima County Regional Flood Control District, Pinal County, Cochise County, Navajo County, the Yavapai County Flood Control District, and the Salt River Project.

New regression equations were made available state-wide in Arizona on June 15, 2017 in StreamStats beta version 4. The new equations can be used for estimating the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual peak-flow exceedance probabilities (2-, 5-, 10, 25-, 50-, 100-, 200-, and 500-year recurrence intervals, respectively), and also the 1-, 3-, 7-, 15-, and 30-day flood-duration flows at the same exceedance probabilities for user-selected ungaged sites. Version 3 is no longer available for Arizona, as a unique method for computing contributing drainage areas for user-selected sites in Arizona sometimes causes delineated basins to appear incorrectly in the version 3 interface.

The reports below document the regression equations available in StreamStats for Arizona, the methods used to develop the equations and to measure the basin characteristics used as explanatory variables in the equations, references to GIS data layers used in the analysis, and the errors associated with the estimates obtained from the equations. Users should familiarize themselves with the reports before using StreamStats to obtain estimates of streamflow statistics for ungaged sites.

Click on this link to obtain general information on the Arizona application, as well as specific sources and computation methods for basin characteristics.