The Monasavu Hydro Electric Project was the first stage of Fiji’s hydroelectric development program and included construction of an 82-metre high embankment dam, a water conductor system and a power station with an initial designed capacity of 40 megawatts which was later extended to 80 megawatts.
The scheme then helped to minimise further expansion of the diesel generating capacity, with corresponding savings in foreign exchange which would have otherwise be required for importing fuel.
Monasavu Dam
The Monasavu Dam is a rock-fill embankment dam on the Nanuku River about 60-kilometres northwest of Nasinu in the Province of Naitasiri Province, in Viti Levu, Fiji. It is located just above the Monasavu Falls and is largest dam, which also withholds the largest reservoir in the country.
The primary purpose of the dam was to produce hydroelectricity power and it supported an 80 megawatts, Wailoa Hydro power station. To offset fossil fuel imports for power production on the island, the Monasavu Hydro Electricity project was authorised by the Fiji Electricity Authority in 1977 and construction began in May 1978. The dam was complete and power station was officially opened on October 20, 1983.
Wailoa Hydro power station
Water from the Monasavu Dam is diverted through nearly 5.4 kilometres of tunnels to the Wailoa Hydro power station to the east of the Wailoa River.
The power station contains four 20 megawatts pelton turbine generators and the drop in elevation between the reservoir and power affords a hydraulic head of about 625 metres.
Wainisavulevu Weir & Wainikasou Power Station
The Wainisavulevu Weir and the Wainikasou Power Station on the upper ridges of Monasavu were developed and included to the Monasavu Hydro Electric Scheme in 2004 increasing water storage and generation capacity.
Water collected at the Wainisavulevu Weir travels through underground tunnels to the Wainikasou Power Station where it generates electricity before it is discharged back into the tunnel and water recollected at the Monasavu Dam to be utilised later at the Wailoa Power Station.
Fiji’s development today can be safely attributed to the Monasavu Hydro Electric Scheme and the fact that it allows for the cheapest cost of electricity in the South Pacific Region then and even today.
Wainisavulevu Weir Raising Project
Further enhancements were undertaken at the Wainisaulevu Weir by raising the height of the weir by an additional 8 metres which was officially opened in November, 2015 for additional water storage and increased generation.
