Drill cores from six holes drilled by the South Australian Engineering and Water Supply Department at the site of the proposed Little Para Dam Water Treatment Works were logged, paying particular attention to core loss, rock defects and intensity of weathering. Core samples from two of these drillholes were forwarded to Coffey and Partners Pty Ltd (Consulting Engineers) for rock shear box tests. The drill core lithology is a moderately weathered to highly weathered dolomitic siltstone, with numerous vuggy quartz veins. Only 30% of the drill core is in pieces greater than 100 mm long (i.e. the average R.Q.D. is 30). The residual angle of friction for core samples from 2 drillholes (DH34 and DH35) using the Hoek Shear Box test ranges from 20º to 44º. The holes DH30-DH34 were water pressure - tested using a double packer. Lugeon values range from nil to greater than 1500. Average values are approximately 50-200 lugeons. On the basis of the results of testing and the weathered nature of the rock, some movement of bedrock during the anchor pullout tests is to be expected.