Hegan, B.D. 1978 Impact of the closure of G4 metal-winning site on the Waipakihi River. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 318 11 p..
Abstract: This report has been prepared at the request of Mr Amos Glass, Ministry of Works and Development, Wanganui, who has been asked by the Rangipo Environmental Committee to recommend restoration measures to be implemented at the closure of the G4 metal-winning site in the Waipakihi River. The report reviews the impact that the closure of the G4 metal-winning site will have on the various geological and hydrological processes operating in the lower Waipakihi Valley. Three proposals are examined in the report but no attempt has been made to favour any particular proposal as this task lies with the Rangipo Environmental Committee.