Groundwater flow velocities near drinking water extraction wells in coastal regions with unconsolidated sediments are crucial for managing water resources. Different methods like environmental tracers and hydrogeophysical measurements have limitations, but active-heating distributed temperature sensing (AH-DTS) can directly measure high groundwater flow velocities near wells. Combining geoelectrical measurements with AH-DTS can provide a 3D view of groundwater flow towards drinking water extraction wells.