Low-flow frequency data for 161 continuous-record gaging stations having eight or more complete years of record are presented for 1-, 7-, 14-, 30-, 60-, 90-, 120-, 183-, and 365-day low flows for frequencies ranging from once in 2 years to once in 100 years. In addition, 8,146 low-flow measurements at 1,515 sites are given. Included are measurements at 623 partial-record stations where correlations with nearby continuous-record gaging stations eventually will be completed, and at 892 miscellaneous measurement sites where only a few measurements were made. Examples are given for determining low-flow characteristics at partial-record stations and miscellaneous-measurement sites. Where the number of measurements are adequate to develop a relation line, they alone are related to concurrent daily flows at a continuous-record gaging station. Where the number of measurements are too few to define a relation with flows at nearby gaging stations, an equal-yield line can be helpful for estimating a relation line. The relation line may be used to transfer low-flow characteristics from a continuous-record gaging station to a site where only discharge measurements are available. Specific conductance of streams, where available, is listed with the discharge measurements at partial-record stations and miscellaneous-measurement sites. Observed conductivity values range from less than 50 micromhos per centimeter at 25° Celsius in the northeast to greater than 1,000 for parts of west-central Minnesota.
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U.S. Geological Survey
Minnesota Water Research Digital Library