This is a point feature class of high-frequency specific conductance and water temperature measurements at specific points in the South Delta. Specific conductance data was collected for the Department’s involvement in the South Delta Salinity Monitoring Special Study required by the State Water Boards 2018 amendment to the Bay-Delta Water Quality Control Plan (Bay-Delta Plan). The candidate dataset includes all data collected for the High-Speed Salinity Mapping component of the study between September 2021 and December 2023. The dataset contains specific conductance measurements collected at fixed time intervals while traversing channel reaches by boat. The dataset is comprised of date/time, run name, channel name, Lat/Long, speed over ground, course over ground, specific conductance (µS/cm), and temperature (C°). Sample water was pumped through a flow-cell, housing a YSI EXO2 sonde and conductivity/temperature sensor. Water quality measurements were collected at frequencies between 1-5 seconds and spatially located using a WAAS-enabled GPS receiver (Garmin GPS 16x). Transect routes encompass all reaches in the southern Delta identified, in the Bay-Delta Plan, as locations for future segment-based salinity compliance. The salinity transects were performed as a method to validate model outcomes, validate stationary, continuous water quality monitoring sites, inform understanding of tidal dispersion in hydrologically complex regions of the study area, and inform the development of protocols for segment- based salinity compliance.