Fraser Scheme
The Fraser Scheme is located near Alexandra and consists of two power stations; one a run of the river scheme and the other utilising storage from the Fraser Dam.
Lower Fraser
Lower Fraser Power Station
Commissioned: 1954
Operating Head: 244m
Flow through Station: 1,800 litres per second
Annual Generation: 22 GWh
The Fraser scheme consists of a dam, intake weir, pipeline, penstock and power station. The original, temporary, generating plant was installed in 1948 as a joint venture between the former Otago Central Electric Power Board and the Public Works Department. Plant was sourced from the Nokomai River Scheme, in Southland and Auckland, to hasten the development of generation while awaiting the delivery of what would become the permanent equipment. The temporary plant produced 500kW of energy, which was needed to meet the extra demands created with the Roxburgh Dam construction.
Work began on the present station in 1951 and was completed for commissioning in 1954. The station’s water supply comes from the Fraser Dam, completed in 1937. The dam is a concrete arch type, 35m high, impounding a lake of 46 ha. About 5km downstream is the intake to the pipeline, which is in the form of a 10m high concrete arch weir. From the weir is a concrete low-pressure pipeline 4.5km in length. Pioneer began a ten-year pipeline upgrade programme in 1999 and the control and communication system was replaced in 2001.
The steel pipeline is 4.4km long. The station’s electrical equipment was completely refurbished in 2001 to provide automatic control and monitoring. The dam and weir are remotely controlled. The turbine and generator were replaced in 2015, and a new concrete tilt-panel powerhouse constructed. The Fraser Dam is owned by The Combined Irrigation Companies and outside of the irrigation season Pioneer Energy operates the Fraser Dam discharge for its benefit, in exchange for supplying a set amount of power to irrigation pumping assets, as rent.
Upper Fraser
The Upper Fraser Power Station
Commissioned: 2019
Flow through Station: 2,000 litres per second
Annual Generation: 33 GWh
The Upper Fraser Scheme is a run of the river hydro scheme consisting of an intake weir, pipeline, penstock and power station. Construction began in February 2018 and the scheme was commissioned in July 2019.
During construction, 11.5km of new roads/tracks and 13.5km of upgraded roads and tracks were built and 10.5km of buried 33kV cable, 5.5km of pipeline were installed. The generation unit is one 8MW five jet pelton-wheel turbine built by Andritz Hydro. The intake is at 1115m amsl (above mean sea level). The scheme takes water from the Fraser River at the intake weir and then travels overland via the pipeline and then drops down to the powerhouse and then is returned to the Fraser River at a point just below the powerhouse.
The intake weir and powerhouse have been designed to be operated remotely. The scheme was officially opened on 17 September 2019. The scheme is built on private farmland, 13km West of Alexandra.
The view from the Upper Fraser access road