+94 81 495 0687 office.mc@ceb.lk

Randenigala Power Station

The Randenigala Project, the fourth major multi-purpose project and the largest reservoir under the Accelerated Mahaweli Development Programme. Randenigala project is located about 26 km. below the Victoria Head works and 6 km. upstream of Minipe anicut from where the main Right Bank and Left Bank canals will divert the Mahaweli waters for irrigation. It is also the reservoir with the largest storage capacity having gross storage of 860 million cubic meters (697,000 acre ft.) at full supply level. The project is expected to generate about 525 GWh of electrical energy which amounts to 20% of the island’s present demand. It will serve as the most important base reservoir for water management in System ‘A’, ‘B’ and ‘C’.

Project Features

The project chiefly consists of the construction of a 94 m.(308 ft) high, 485 m.(1590 ft.) long Rock-fill dam across Mahaweli, created a reservoir of 860 million cu.m. (697,000 ac.ft.). The Power House on the Left bank immediately downstream of the dam has an installed capacity of 126 MW. A steel lined tunnel 6.2 m. diameter, 270 m. long, convey water to the Power House to run the turbines. The triple gated chute spillway is 48 M. wide, about 232m. long and is capable of discharging the probable maximum flood of 8085 cu.mecs.


The total cost of these Headworks is approximately Rs. 4898 million of which Rs. 1207 million is the local component and Dautsche Marks 410 million is the foreign component in 1985. The Federal Republic of Germany first granted a loan for a value of about DM 240 million (Rs.2160 million) and has extended a loan to the value of DM 400 million on favorable terms for Randenigala Project. (Rs. 2,528,455 as at the balance sheet 2004) (Rs.’000)

Consultancy services

The consultants for the Project is Joint Venture Randenigala (JVR), a firms, Salzgitter Consult GmbH, Agrar-Und Hydro-technik GmbH and Electrowatt Engineering Services Ltd along with the Engineers of the Central Engineering Consultancy Bureau. (CECB)
Construction work commenced in 1982. The reservoir was impounded in March 1986, construction of the rockfill dam, spillway and power station were completed in 1986, according to schedule. The two turbine generator units were commissioned in August and September 1986.


A dam at Randenigala site with power station and other appurtenant structures together with a lower dam at Rantembe (immediately below the confluence of the Uma Oya with the Mahaweli ganga), and power station.

  • Installed capacity 61 MW X 2
  • Expected annual average energy
    300 GWh
  • Commissioned in 1988
  • Main contractors
    • Civil – JV Randenigala
    • Electromechanical – BBC
    • Hydro mechanical – Sulzer Escher Wyss
  • Located 60 km south-east of Kandy
  • Reservoir
    • Catchment area : 2330 km2
    • Usable water volume : 565 MCM
    • Maximum level : 232 m above MSL
    • Minimum level : 203 m above MSL
  • Headrace – No
  • Penstock
    • Steel circular, 6.2 m diameter, 270 m length
  • Tailrace
    • Length : 12 m ; Maximum level : 153 m above MSL;
      Minimum level : 148 m above MSL
  • Generator (ABB)
    • Conventional vertical
    • 81000 kVA, 0.85 PF, 12.5 kV, 3741 A
    • 50 Hz, 30 poles, 200 rev/min
    • Exciter : 236 V, 1435 A
  • Turbine (Sulzer Escher Wyss)
    • Vertical Francis
    • Output : 63.59 MW @ 77.75 m effective head (Rated),
      71.78 MW @ 84 m effective head (Maximum)
    • Rated discharge : 90 m3/sec
    • 200 rev/min