At a Glance
Paerau and Patearoa Power Stations generally use ‘run of river flows’ to generate electricity during the winter months. In summer, Paerau Station generates from available water (irrigation and excess water), while Patearoa Station only operates if excess water is available.
The scheme takes water from the Taieri River at Paerau Weir while a residual flow is maintained in the river. Floodwater in excess of the storage and scheme capacity is passed through floodgates and down the Taieri River. The water is diverted through a 1.3 kilometre (km) long tunnel and along an aqueduct before it enters the penstock of Paerau Station, where twin turbines can generate up to 10 MW.
Paerau discharges the water into a ponding area which forms the beginning of a 35 km long irrigation distribution canal system. Patearoa Station draws from the east side irrigation canal and uses the water to generate with twin turbines driving a single induction generator which produces up to 2.3 MW, before it releases the water back to the Taieri River.
In summer at times of low flows the Maniototo Irrigation Company releases water from the Loganburn Reservoir to maintain minimum flows in the Taieri River and to cover their irrigation demand.
Resource Consents for the Paerau and Patearoa Scheme were approved in 1999, for a 35 year term. These consents are due for renewal in 2034.