Geophysical data were collected on January 13, 2022, from a reach of East Fork Poplar Creek in Oak Ridge, Tennessee to gain a better understanding of surface water/groundwater exchanges. This data release contains the following types of data: waterborne self-potential (WaSP), and surface -water temperature and conductivity data collected by the U.S. Geological Survey (USGS) from 220-meter (m) long survey reach, stream specific conductance data calculated from surface-water temperature and conductivity, and electric resistivity tomography (ERT) data collected along four linear profiles on the floodplain adjacent to the WaSP survey reach. The ERT data were measured by hydroGEOPHYSICS, Inc. The WaSP logging data were measured by the USGS in the stream from an instrumented kayak by floating the kayak downstream along the west bank of the survey reach. Two repeated profiles of WaSP data were acquired along the west bank. Prior to data collection, an electrode-drift test was performed in an eddy at the upgradient end of the survey reach to record the transient drift characteristics of the WaSP electrodes. During data collection, the WaSP voltages were continuously logged, plotted, and monitored in real-time at a period of 1 second per measurement using an Agilent U1252B data-logging multimeter connected to an onboard laptop computer and a 0.55-m long electric dipole comprised of two freshwater-submersible, non-polarizing copper-sulfate electrodes that were suspended approximately 15 centimeters into the stream beneath the kayak keel. Surface-water temperature and conductivity data were continuously logged at a period of 1 second per measurement by an Onset HOBO conductivity and temperature logger that was suspended in the stream beneath the kayak keel at approximately the same depth as the WaSP electrodes. The geospatial coordinates of each measurement were recorded into the onboard laptop computer during data collection by logging output from a Trimble DSM232 differential global positioning system (GPS) receiver at a period of 0.2 seconds per measurement. However, the GPS signal was rather poor in many locations along the survey reach and numerous WaSP measurements and surface-water conductivity and temperature measurements did not receive corresponding geospatial coordinates. The missing geospatial coordinates were interpolated along the survey reach by drawing a survey path-line through the measurement coordinates that were obtained, and then applying a cubic-spline interpolant to the path-line. ERT data included with this data release were measured on March 7–11, 2022, along four linear survey profiles on the floodplain that were oriented adjacent and approximately parallel to the WaSP survey reach. One ERT profile, surveyed on the east floodplain, was 228-m long and consisted of 77 stainless steel electrodes separated by 3-m intervals. Three ERT profiles, surveyed on the west floodplain, were 249-m long and consisted of 84 stainless steel electrodes separated by 3-m intervals. All ERT data were measured with an Advanced Geosciences Incorporated SuperSting R8 resistivity meter with accompanying 56-electrode and 28-electrode switch boxes, using the standard Wenner electrode array configuration (Zodhy and others, 1974 ) augmented by gradient array measurements (Cubbage and others, 2017). Horizontal GPS coordinates of the ERT electrodes were recorded by the Trimble DSM232 differential GPS receiver used in the WaSP survey and vertical coordinates of the ERT electrodes were acquired from a 2-m digital elevation model provided by the Oak Ridge National Laboratory.