Patea Hydro Scheme Case History Environmental Predictions and the Outcome
Author: Peter B. Riley
Presented/Published: Commission Internationale Des Grans Barrages, 1991
Keywords: Patea Dam, environmental predictions.
Abstract:
The Patea Hydro Electric Scheme was the first of the local authority hydro electric schemes to be subjected to full environmental scrutiny. Many environmental planning techniques which are now standard practice were developed during the approval processes for the Patea Scheme. This paper examines the procedures which were followed, the predictions which were made on scheme behaviour, and compares these with the present situation 6 years after the lake has been filled.
In the 1970's the world economy was severely affected by disruption in oil supply from middle east states. A potential world energy crisis was seen which would affect New Zealand badly. A Government policy was formulated encouraging local authority Electric Power Boards to develop hydro resources within their area. Favourable Government finance was offered. Local energy resources were examined, including environmentally sensitive rivers. The Egmont Electric Power Board, a local power supply authority, responded by investigating hydro resources within its own region. Consultants were appointed, with Beca Carter Hollings & Ferner Ltd as lead consultant, and the author as Project Manager. The Patea River was chosen as having the potential to supply a large proportion of the Board's electricity demand.
The chosen scheme had a dam in a remote section of the Patea River 42 km upstream from the mouth. The dam-would raise the water level by 60 m creating a narrow sinuous lake which extended 47 km back through remote bush covered gorges. The power station output of 30 MW would generate directly into the Egmont Electric Power Board supply network. Fig. 1 shows the dam location and catchment area.
