Integrated geophysical investigations using 2D electrical imaging, vertical electrical sounding andrnmagnetic methods have been conducted for engineering site characterization of a dam foundationrnlocated at Hizaeti Afras near Wukro town, Tigray Regional State, North Ethiopia. The mainrnobjective of the study was to examine the suitability of the subsurface geological formations andrnstructures for foundation of the proposed dam project.rnFrom the results of the survey, it has been possible to map the stratification of the subsurfacernlayers, their vertical and lateral extent, and hence the depth to the sound bedrock suitable for damrnfoundation is determined. It has also been possible to map areas of weakness in the subsurface thatrncould be detrimental to the life of the dam.rnAccording to the interpretation of the geophysical results, the near surface geology of the studyrnarea includes three layers. The first layer which is the top soil has considerably varying thicknessrn(2m-9m) over the area. The second layer is interpreted as a weathered and fractured limestonernwith shale intercalation. And it extends to depth of about 27m on the western and 33m on thernnorthern part of the survey area. However, its depth extent on the eastern and southern part isrnabout 17m to 21m. The third layer which is characterized by higher apparent resistivity response isrninterpreted as black limestone which could be considered as the bed rock in the area. This layerrnhas undulating nature and the depth to this bed rock surface is deeper in the western and northernrnportions and become shallow towards the eastern and southern portions of the survey area.rnBased on the pseudo-depth and sliced-stacked depth maps the study area can be divided in to threerndistinct zones. The first zone which is characterized by very low apparent resistivity valuesrnincludes the western and northeastern portions of the study area. This is interpreted to be thernresponse of the water saturated weathered and fractured limestone. The second zone that exhibitsrnintermediate apparent resistivity values comprises of the central part of the study area with arnnarrow strip in the central-east. This area is interpreted to be covered by weathered and fracturedrnlimestone with shale intercalation. The third zone which is characterized by very high apparentrnresistivity response comprises of the southeastern part of the area and it is interpreted as a blackrnlimestone formation.rnFrom a combined interpretation of the geophysical data, four weak zones have been identifiedrnover the survey area which are oriented in N-S, NE-SW, NW-SE and E-W direction. The N-Srnrunning major weak zone is in the region (about 100m -110m from the western side of the damrnaxis) where an earlier dam built on the site has broken through.rnAs a further conclusion from the work, it is suggested that the dam axis has to be relocatedrntowards the downstream side by about 150m from the intended location. This relocated dam axisrnwill get the sound foundation at shallower depth and has a reduced risk from the weak zonesrntrending NE-SW and NW-SE. In addition special attention should be given to the western andrnnortheastern part of the study area and the weak zones in designing and implementation of the damrnfoundation.