Hegan, B.D. 1976 Engineering geology of the Rangipo tailrace tunnel. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 253 61 p.
Abstract: This report presents the results of surface and subsurface geological investigations for the tailrace tunnel of the Rangipo Power Project will divert most of the waters of the Waikato River above the Waihohonu Stream confluence through the headrace tunnel sited along the western flanks of the Kaimanawa Mountains. An underground powerhouse is to be sited beneath the lower reaches of the Waikoko Stream and water will be led away from the powerhouse through a tailrace tunnel and discharged into the Tongariro River at Beggs Pool. The tailrace tunnel will be approximately 2900 metres long and will have a final concrete lined diameter of 4.5 metres. Plan 100/R/26 is appended to this report. Copies of the drill hole logs together with C E Ingham's geophysical survey report are available on request from the office of project engineer, T.P.D. (auth)