Continuous resistivity profiling (CRP) in the Similkameen River above Enloe Dam, Okanogan County, Washington

A continuous resistivity profiling (CRP) survey was conducted in a 1.2-mile reach of the Similkameen River upstream of Enloe Dam in December 2021 in Washington State. The survey was performed to characterize the resistivity of the water column and subbottom materials using the CRP method. The survey consisted of eight longitudinal profiles roughly equivalent in length and conducted in the right, left and center of the channel. In this survey, a 100-m cable with 11 electrodes spaced 10 m apart and outfitted with floatation aids was towed behind a boat at speeds of 1-1.5 m/s and data were collected using the dipole-dipole array type. In this configuration, two electrodes nearest the boat transmitted electric current into the water and subbottom materials, and eight electrical potential measurements were made every 1 s using the trailing nine electrodes. The boat speed and measurement rate allowed for complete measurements every 1-2 m along the profile. In general, the depth of measurement increases with the spacing between electrodes and is limited to 10-20 m depending on conditions. Bulk resistivity at specific depths in the vertical profile is determined through a process of inversion. This data release contains the raw CRP data in text file format that can be used in the inversion process, as well as the inverted files used in the calculation of sediment above bedrock impounded by Enloe dam.