Operation start: 1953

Altitude above the sea level: 1,376.0 m

Pressure (h) 285 m

Installed capacity: 224 MW

Turbines: 4 x 56 MW

Average annual production: 202 GWh

Open diversion canals: 7,268.34 m

Diversion tunnels: 11,503.07 m

Operation regime: The whole year


The Argel HPP (formerly Gyumush) is the third stage of the Sevan-Hrazdan Cascade. It is the most powerful Hydro Power Plant of Armenia. The plant is located on the left bank of the Hrazdan river.

The estimated water consumption of the plant makes 90 cubic meters per second. Diversion is of mixed type. The time of water to reach the place is 100 minutes by diversion, and 5-6 hours by the riverbed. The water diversion tunnel is connected to the pressure chamber by a 293.2 m long supply canal. The supply canal is connected to the Daily Regulation Basin (DRB) through the feeding penstock. The DRB is used to cover the maximum loads of the power system and to be used in emergency working procedures. The capacity of DRB is 300,000 cubic meters, the energy capacity is 194,000 kWh.

The estimated water consumption in case of the maximum capacity is 22.5 cubic meters per second. The diversion of the plant is fed from the ten-day regulation reservoir of Akhpara.

Akhpara Reservoir
  • Capacity: 5.6 million cubic meters
  • Useful capacity: 3.1 million cubic meters
  • Dead volume: about 2 million cubic meters
  • Full Reservoir Level (FRL)` 1695.5 m
  • Dead Storage Level (DSL): 1692 m
  • Dam height: 15 m, base width: 75.12 m, roof width 5.5 m, length: 117.3 m
  • The mirror surface of the reservoir at 1695 meters is 1.7 million square meters
  • Energy capacity: 2.65 million kWh