Turnbull, I.M.; Thomson, R.; Read, S.A.L. 1975 Shotover River catchment. Sediment sources survey, geological report. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 227 16 p.
Abstract: At least one million tonnes of sediment, most of which comes from the Shotover River catchment, is being transported into the Clutha River system and is filling the lake formed behind the Roxburgh hydro-electric dam [location on map on p. 2]. As several further hydro electric dams are proposed on the Clutha River downstream of the Shotover River junction, Ministry of Works and Development (Power Design) has requested an investigation into the sediment coming out of the Shotover River catchment. In the summer of 1974/1975 fieldwork was commenced by the Ministry of Works and Development (Water and Soil Division) and Otago Catchment Board (OCB) personnel, with some assistance from the NZ Geological Survey, in order to identify the sources and types of sediments entering the Shotover River and to classify, measure, document and present these. This report describes the geology of the schists which form geological basement and the superficial deposits overlying basement. The process which control erosion in the catchment and which are providing the Shotover River with sediment are also described. Observations on the importance of the various sediment sources are then given, together with a limited discussion of measures for controlling the erosion and reducing the sediment load in the river. (auth)
