Extension of streamflow and dissolved-solids records at selected sites in the Colorado River basin, Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming, 1940-83

Monthly streamflow and dissolved-solids concentration were estimated for periods prior to the initiation of data collection at selected sites in the Colorado River basin. Techniques used for this record extension included simple and weighted least-squares regression. Streamflow records were extended at 5 sites and dissolved-solids records were extended at 13 sites. Records were extended back through 1941 to provide a completely concurrent data set for all sites. Standard errors were 5 to 74% for monthly streamflow and 3 to 27% for monthly, flow-weighted dissolved-solids concentration. The extended records at all sites were consistent with records from the historical period. (USGS)