The determination of geotechnical charactertiscs of waste rock is essential for addressing issues of in situ hydrology and the stability of steep and high-standing dumps. Based on laboratory investigations and numerical modeling, this paper gives the geotechnical properties of a selected waste rock under saturated and unsaturated conditions. Results indicated that the engineering behavior of the investigated waste rock is similar to granular soils and governed by the “well-graded” and “very angular” nature of the materials. The samples exhibited low air entry values (0.2 and 0.8 kPa) and low water storage (0.44) along with a high saturated hydraulic conductivity (1 × 10⁻⁵ m/s). The hydraulic conductivity dropped sharpely beyond the air entry value by up to eight orders of magnitude at 200 kPa. The shear strength was identical to loose coarse materials and was primarily derived from the angle of internal friction that measured 37° to 39°, similar to the angle of repose. Additional strength can be availabe in the form of effective cohesion due to clays and cementation and apparent cohesion due to matric suction.