Peak-streamflow , Mean-streamflow , and Low-streamflow Equations for Western Colorado

Science Center Objects

Reliable peak-streamflow data are critical to design transportation infrastructure, such as bridges, culverts, dams, and floodplain inundation maps. At gaged sites, where sufficient long-term streamflow data have been collected, statistics can be obtained from available publications, by an analysis of available data in the U.S. Geological Survey (USGS) National Water Information System (NWIS) database, or other sources of flood information. However, streamflow statistics such as peak-, mean-, and low-streamflow also are needed at ungaged sites where no site-specific streamflow data are available. Additional streamflow data, new Geographic Information Systems (GIS) basin and climate characteristics, and innovations in flood-frequency analysis and statistical hydrology may improve the reliability of the regional-regression equations in the Northwest, Southwest, Rio Grande and Mountain hydrologic regions of western Colorado. Engineers and scientists then will be able to incorporate these updated estimates for proper floodplain regulation, dam-safety design, and other uses.


Study area with the streamgages used to develop the peak-, mean-, and low-streamflow equations for western Colorado

Study area with the streamgages used to develop the peak-, mean-, and low-streamflow equations for western Colorado

  1. Compile systematic flood data available at streamgages in western Colorado and adjacent states with a minimum of 10 years of data that have minimal upstream regulation and urbanization and are not redundant with other streamgages,
  2. perform flood-frequency analysis at each streamgage following guidelines outlined in Bulletin 17C and compute the mean- and low-streamflow statistics at each streamgage,
  3. delineate the drainage basin and compute and compile climate and basin characteristics for each streamgage,
  4. perform regionalization analysis for each streamflow statistic and define hydraulic regions,
  5. develop the final regional-regression equations for peak-, mean-, and low-streamflow,
  6. determine prediction errors for the regional peak-, mean- and low-streamflow equations,
  7. publish results and methods in a USGS Scientific Investigations Report, and
  8. Add the new regional-regression peak-, mean- and low-streamflow equations for western Colorado into the USGS StreamStats program.