Groundwater leaking from tunnel face is an important factor of face evaluation for rock stability assessment such as use of the Rock Mass Rating system (RMR). Currently, engineers are visually observing tunnel faces, but this method may lead to variation of results by different engineers. In addition, the number of skilled engineers is decreasing in the world, and young engineers need to be educated at the same level as skilled engineers. This research focus on groundwater and propose a method to measure the quantity of groundwater on the face using image analysis. The area where the groundwater flows was determined by using an image analysis, frame subtraction method which is based on images taken by spectral cameras. Also, the velocity of water flow was determined by Space Time Image Velocimetry (STIV) image analysis. The results indicate the possibility of measuring the extent of the flowing groundwater on face and the velocity of the flow by image analysis.