P. M. JAMES and D. J. PAUL write: In their paper, the authors give a useful background appraisal of the Upolo and raise a number of geotechnical issues on the Afulilo scheme. However, the authors base their knowledge on the very preliminary investigations gathered during the feasibility study for the hydro-power scheme, which terminated in 1986. Since that time extensive investigations and new studies have been undertaken for the design of the scheme by Lahmeyer International (Germany) and Kinhill Cameron McNamara (Australia) (Consortium Lahmeyer International & Cameron McNamara 1988). Prior to design and construction the following activities, among others, were performed in the years 1987 and 1988:
12 core drillings totalling 375.7 m,
11 seismic traverses of 3.15 km in length,
8 geological profiles, 459 m long in total,
18 auger drillings, and
40 test pits.
The project is now well into the construction phase and the writers, who were involved in these additional studies, are replying to the authors' paper on behalf of the Consultants' consortium.
In order to answer some of the specific concerns raised by the authors, a brief and updated geological description of the Afulilo Project is given.