Operation start 1956

Power plant: Rock-cut

Altitude above the sea level: 1,236 m

Pressure (h): 118 m

Installed capacity: 70.56 MW

Turbines: 3 x 23.52 MW

Average annual production: 62.4 GWh

Open diversion canals: 3,891.25 m

Diversion tunnels: 4,133.82 m

Operation regime: The whole year


The Arzni HPP is the fourth stage of the Sevan-Hrazdan Cascade. The structure of the power plant is the only rock-cut structure in Armenia. It is located on the right bank of the Hrazdan river.

Diversion is of mixed type. The estimated consumption is 70 cubic meters per second, the time of water to reach the place by diversion is 45 minutes. The estimated water consumption is 23.2 cubic meters per second. The idle flow rate is 2.3 cubic meters per second.

The plant diversion is supplied by the Argel Reservoir, the main criteria of which are the following:

  • FRL" 1367 m
  • DSL: 1363.8 m
  • Overall capacity: 1.125 million cubic meters
  • Useful capacity: 0.420 million cubic meters
  • Dead volume: 0.7 million cubic meters
  • Energy capacity of reservoir: 112.000 million kWh

An equalization tower is placed on the pressure water pipe to protect it from hydraulic shocks. A water flow regulator is installed for keeping the water flow from the reservoir to the diversion constant, depending on the horizon.