1961-1981 The Complex of Hydraulic Works for Transfer of the Arpa and Yeghegis

The scope of the Project included:
1. The headwork is Kechut Reservoir on the Arpa River, the storage capacity of which is 25 mln. m3 and the dead volume – 7 mln. m3 with the emptying volume of 77 mln. m3 .

2.  The reservoir has a puddle-core rock-fill dam with 47.3 m height, the length and width of crown being 234 m and 14 m respectively and the maximum width at the base being 190 m.

3.  The water intake of the Arpa-Sevan conduit is situated on the right bank of reservoir, and
the entrance opening with flat gate has 3.5 m × 3.0 m size and ensures the throughput of 16 m3/sec water flow via Tunnel No.1.

4.  The shaft-type irrigation outlet has a pressure tunnel of 2.6 m in diameter. The length of irrigation tunnel is 292 m and the discharge through the tunnel varies from 30 to 32 m3/sec depending on the head at water intake.

5.  The maximum water flow through the “Daisy” shaft-type catastrophic overflow reaches the value of 272 m3/sec. The clear diameter of shaft water outlets and of the discharge is 6 m.

6.  18 km long Tunnel No.1 of the Arpa-Sevan conduit takes its origin from the water intake of Kechut Reservoir. The tunnel has 3.7 m ×3.6 m clear dimensions and has a trough-shaped cross section.

The tunnel has been driven from four faces, the first and the fourth faces being drifted from the intake and outlet portals respectively, and the corresponding counter second and third faces drifted from Shaft No.1. The diameter of Shaft No.1 is 6 m and its height is 192 m.