Waterborne Gradient Self-potential, Temperature, and Conductivity Logging of the Rio Grande from Leasburg Dam State Park, New Mexico to Canutillo, Texas During Bank-Full Conditions, June-July 2020

This data release contains waterborne gradient self-potential (SP), surface-water temperature, and surface-water conductivity data measured continuously along approximately 72 kilometers (km) of the Rio Grande over the Mesilla part of the Hueco-Mesilla Bolson aquifer. The geophysical measurements were made from a kayak between June 26, 2020 and July 2, 2020 during peak releases of surface-water in the range of 54 to 65 cubic meters per second from Elephant Butte and Caballo Dams upstream from the surveyed reach. The full geophysical survey extended between Leasburg Dam in Leasburg Dam State Park, New Mexico, and the Farm to Market (FM) 259 bridge in Canutillo, Texas. For data-collection purposes, the full survey reach was divided into four smaller segments, each approximately 15 to 24 km in length. The first segment began at Leasburg Dam and ended a few meters downstream from the Shalem Colony Trail bridge in Las Cruces, New Mexico. The second segment began a few meters downstream from the Shalem Colony Trail bridge and ended about 160 meters upstream from the Mesilla Diversion Dam in Mesilla, New Mexico. The third segment began a few meters downstream from the Mesilla Diversion Dam and ended a few meters downstream from the New Mexico State Road (NM) 189 bridge in Vado, New Mexico. The fourth segment began a few meters downstream from the NM 189 bridge and ended a few meters downstream from the FM 259 bridge in Canutillo, Texas. Voltage data contained in this data release were continuously logged at a period of 1 second per measurement along each of the four segments using an Agilent U1252B multimeter connected to a 0.5-meter electric dipole consisting of two freshwater-submersible non-polarizing copper-sulfate electrodes. Surface-water temperature and conductivity data were continuously logged along each segment at a period of 2 seconds per measurement. The resulting data sets contained in this data release include more than 44,000 measurements of voltage from profiling and drift tests, 24,000 measurements each of surface-water temperature and conductivity in the Rio Grande, and the geospatial coordinates of each measurement. Two profiles of electric resistivity beneath the Rio Grande riverbed are included. These profiles were produced by helicopter frequency domain electromagnetic surveying. One profile represents resistivity at an average depth of 3.5 meters beneath the riverbed and the second represents resistivity at an average depth of 50 meters beneath the riverbed.