Streamflow gain/loss in the Republican River Basin, Nebraska, October 1998

This arc and point data set contains streamflow-measurement sites and
reaches indicating streamflow gain or loss under base-flow conditions
along the Republican River and tributaries in Nebraska during October
25 to 28, 1998 (Boohar and others, 2000). The streamflow measurements were
made to obtain data on ground-water/surface-water interaction.
Flow was observed visually to be zero, was measured, or was estimated
at 374 sites. The measurements were made on the main stem of the
Republican River and all flowing tributaries that enter the Republican
River between Swanson and Harlan County Reservoirs in the Nebraska part
of the Republican River Basin. Tributaries were followed upstream until
the first road crossing where zero flow was encountered. Measurements also
included estimates of average wastewater discharge during the period when
the flow measurements were made, based upon data obtained from towns
having measureable wastewater discharge. For selected streams, points of
zero flow upstream of the first zero flow site also were checked.

Streamflow gain or loss for each stream reach was calculated by
subtracting the streamflow values measured at the upstream end of
the reach and values for contributing tributaries from the
downstream value. The data obtained reflected base-flow conditions
suitable for estimating streamflow gains and losses for
stream reaches between sites. However, due to fluctuations in streamflow
on the main stem of the Republican River above Swanson Reservoir during the
measurement period, flow measurements on the main stem could not be used
for calculating reach gains and losses. Flows measured on tributaries to
the Republican River above Swanson Reservoir were of suitable quality
to use for streamflow gain/loss calculations. Flows on Sappa Creek did
not reflect base-flow conditions and thus were not suitable for
investigating ground-water/surface-water interaction.

This digital data set was created by manually splitting the lines
from a 1:250,000 hydrography data set (Soenksen and others, 1999) at
every streamflow-measurement site. Each set of stream segments between
measurement sites was assigned a unique reach number.