Paterson, B.R. 1972 The threat of volcanic pollutants to the fish of Lake Rotoaira. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 137 11 p.
Abstract: The commissioning of the Western Diversions tunnel, canal and dam system of the Tongariro Power Development commenced in September 1972. When this has been completed, water will be collected from stream catchments on the western flanks of the Tongariro National Park volcanoes, and diverted into Lake Rotoaira. (see plan 100/GEN./5 appended). The question has been raised of the likelihood of volcanic pollutants which could be toxic to fish reaching Lake Rotoaira. It is important to consider this possibility prior to the completion of commissioning as it could be found necessary to instal a warning device to protect the fish in Lake Rotoaira be ensuring that toxic substances be diverted before entering the tunnels. This would eliminate the necessity of draining the whole or parts of the Western Diversions system with the resulting waste of water storage as well as other operational problems. Should it be decided to instal such a warning device this should be operating before the completion of commissioning as the next volcanic eruption could occur at any time. Information for this report has been gleaned from records and internal reports from several Government Departments. Thanks are acknowledged for all personal communications from employees of these departments who have most willingly offered their assistance. (auth)
