The Coal Authority undertakes monitoring of shafts and boreholes across Great Britain’s coalfields. As part of this monitoring geophysical instruments are used to profile shafts and boreholes and the water contained within. This is often undertaken for reasons such as assessing the condition of a monitoring point or identifying different water types prior to the collection of water chemistry samples. Here we present the water temperature and electrical conductivity data collected as part of this geophysical monitoring. The data illustrate changing temperature (ºC) and electrical conductivity (µS/cm) of mine water within flooded mine shafts and boreholes. The parameters are measured on a 1cm resolution throughout the length of the shaft or borehole.