Abstarct: Damghan dam is an embankment dam (earth dam or rock-fill dam) with impermeable clay core that constructed on the Ali spring’s river with a reservoir’s volume of about 21 Mm3. Right and left abutments of the dam construction are situated on the Erika Triassic limestone and Pleistocene conglomerate and shale, respectively. The exposed of springs in downstream on the right abutment structure is one of the main important issues in Damghan dam site. In this study, the origin of downstream springs and seepages, possible hydraulic connection between the reservoir and downstream springs and also probability potential leakage direction were studied using geological, geotechnical, hydrogeological and hydrogeochemical investigation. Geological conditions, hydraulic data and hydrochemical results indicate that the hydraulic relationship is exist between the dam reservoir and right abutment downstream springs. baxsed on one year water budget calculation, the groundwater balance in the right abutment was negative. So, the limestone formation above the springs can’t provide alone the total downstream spring’s discharge volume. Therefore, some of discharge water from the downstream springs and seepages must be supply from another source, which this potential source could be the dam reservoir. Given the amount of leakage in the downstream, the volume deficit of the reservoir is higher than expected, indicating that the water of reservoir also leak from other paths through the joints and cracks or hidden fault. Geotechnical results indicate the existence of a crashed zone with large fractures and high permeability in the right abutment, which is the main potential leakage zone. Finally, with regard to above results and hydrogeological conditions of Damghan dam site, seepage and leakage of water most probably occurs through fractures on the right abutment and also below the dam foundation.