The hydraulic properties of the subsurface system created in the course of the Γ-Project, Tohoku University, are presented. Furthermore, for a subsurface system consisting of an artificial crack and two wells for geothermal heat extraction, methods are proposed for predicting the flow impedance and for estimating the area of effective heat exchange surface from tracer test. First, water flow in a penny shaped crack with an inlet and an outlet was analyzed. Based on this analysis, a method was constructed for predicting the flow impedance of this subsurface system just stated. The method was then applied to the subsurface system of the Γ-Project. The predictions agreed well with the field experimental results. The velocity field of the flow in a penny shaped crack was also applied to the simulation of the outlet tracer response profile. The results of the simulation were compared with those of the tracer test performed during the Γ-Project to obtain the effective heat exchange surface.