Streamflow Estimates in Selected Wisconsin Streams

The Wisconsin Department of natural Resources needs streamflow information in lake basins where lake-rehabilitation programs are implemented but where long-term stream-gaging stations are not justified. The U.S. Geological Survey provided streamflow estimates for 24 streams in Wisconsin. The estimates were made by the use of (1) midmonthly measurements, (2) basin characteristics, and (3) drainage-area-discharge relations. The midmonthly measurement technique probably provides the best estimtes of streamflow in streams that may be affected by storage in lakes. However, it is costly, requires 1 year of measurements, and results cannot be obtained until streamflow data from gaging stations in the area have been processed. The basin-characteristics technique is quicker and provides good estimates, but defining the basin parameters is difficult. The drainage-area-discharge technique also provides good streamflow estimates, and it is quick, convenient, and inexpensive. However , the streamflow estimates obtained from drainage-area-discharge relations may be biased because the technique is based on gaging-station records for large steams that do not have the variability of smaller streams and that typically do not reflect the influence of lake storage.