A method and system for characterizing subsurface hydraulic fractures, specifically the effective permeability thereof, are disclosed. One method includes transmitting electromagnetic signals from an electromagnetic source toward a subsurface hydraulic fracture location, capturing electromagnetic signal measurements of a subsurface hydraulic fracture on the Earth's surface above the subsurface hydraulic fracture location at a plurality of electromagnetic receivers, and associating characteristic hydraulic flow parameters with the electromagnetic signal measurements to determine one or more fracture zones. The method further includes determining an effective permeability of the one or more fracture zones, thereby determining an effectiveness of hydraulic fracturing in the subsurface hydraulic fracture location.