Streamflow regressions and annual and semimonthly exceedance probability statistics for wild and scenic rivers, Owyhee Canyonlands Wilderness, Idaho

The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, used streamflow measurements at 11 partial-record sites and related them to nearby USGS or Idaho Power Company real-time streamgages (index sites) to provide daily mean streamflow values at ungaged (partial-record) sites within the Wild and Scenic River of the Owyhee Canyonlands Wilderness, Idaho. Daily mean streamflow was estimated by developing a regression relationship between streamflow at each partial-record site and the index site for the period of record of the index site. The regressions are then used to estimate annual and semimonthly 20-, 50-, and 80-percent exceedance probability streamflow statistics at each partial-record site. The streamflow statistics will support the Bureau of Land Management’s effort to develop and file a federal water rights claim for sustaining outstanding remarkable values for rivers designated as “Wild,” “Scenic,” or “Recreational”.