Hegan, B.D. 1988 Mohaka River power investigations : report on the engineering geological investigations : M42 (Willowflat) site. [Lower Hutt]: New Zealand Geological Survey. New Zealand Geological Survey report EG 399 41 p.
Abstract: Preliminary engineering geological investigations to assess the feasibility of the proposed power development options at the Willowflat (M42) site on the Mohaka River have been completed. While the dam site itself appears free of geotechnical features that could preclude the future construction of an embankment dam there are major difficulties in siting associated structures because of the known extent of the Murphy Road landslide immediately downstream. A detailed assessment of reservoir stability was not undertaken during this study, although sites of prehistoric natural dams have been located within both the Mohaka and Te Hoe valleys. It is recommended that further investigations should address the siting of the engineering components of the scheme within the geological framework presented in this report. (auth)