Kermode, L.O.; Thompson, B.N. 1972 Arapuni dam diversion tunnel, geological report on drillhole investigations. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 128 9 p.
Abstract: During an inspection of the concrete lining of the diversion tunnel, cracks in the ceiling somewhat parallel to the tunnel centre line were noticed extending downstream for some 20 ft from the downstream gate. Routine maintenance work on the tunnel gates provided the opportunity to investigate the surrounding rock. Ministry of Works has core-drilled four holes in the eastern abutment of the dam to determine if there is any geological reason for the cracking of the concrete lining. Geological information derived from these holes is contained in this report. (auth)