Tracer tests were conducted as part of decameter-scale in-situ hydraulic stimulation experiments at the Grimsel Test Site to investigate the hydraulic properties of a stimulated crystalline rock volume and to study the stimulation-induced hydrodynamic changes. Temporal moment analysis yielded an increase in tracer swept pore volume with prominent flow channeling. Post-stimulation tomographic inversion of the hydraulic conductivity, K, distribution indicated an increase in the geometric mean of logK and a decrease in the Dykstra-Parsons heterogeneity index. These results indicate that new flow path connections were created by the stimulation programs, enabling the tracers to sweep larger volumes, while accessing flow paths with larger hydraulic conductivities.