DS-777 Spatial Location of Gages with Total Flow and estimated Base Flow, for the Predevelopment Simulation Period for the Northern High Plains Groundwater-Flow Model in Parts of Colorado, Kansas, Nebraska, South Dakota, and Wyoming

Baseflow is the portion of streamflow derived from groundwater flow. It is an important
component of the groundwater budget, and can be estimated using known total streamflow
at given points through time. Daily streamflow data was collected from 25 streamflow gaging
stations across the northern High Plains Groundwater Availability Study (NHPGAS) area from
the National Water Information System (NWIS) and the Nebraska Department of Natural
Resources Stream Gaging Data Bank. The data from each site was processed using the
BFI program, version 4.15 (Wahl and Wahl, 2007) to determine the baseflow component
of total streamflow at each site. The average daily baseflow was computed for the year of
1940. The resulting baseflow values were applied as calibration targets to the end of the
predevelopment model.