Read, S.A.L. 1974 Ohau A power project: Ohau A powerhouse, slope debris on penstock slope. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 192 8 p.
Abstract: The excavation of the Ohau A powerhouse site down to R.L. 468m has been completed. The material excavated was Mt John Outwash Gravel except for some slope debris on the penstock slope. This report outlines the extent of the slope debris remaining on the penstock slope and discusses its engineering significance. Data for the report was obtained from logging of exposure on the penstock slope as the excavation progressed and a te st cut dug after the excavation was completed (geological log of the cut is Fig 1). A plan showing the extent of the slope debris on the penstock slope is also included in the report (Fig 2). together with a geological cross-section along the powerhouse centre line (Fig 3). No detailed logging of the Mt John Outwash Gravel in the rest of the excavation has been done. (auth)