Since the water level in the lake did not rise as fast and as much, on 20 April 1981 the Council of Ministers of the Soviet Union made a decision for the construction of the Vorotan–Arpa tunnel. This long tunnel was begun from the Spandarian Reservoir on the Vorotan River further south from Kechut. Due to the Nagorno-Karabakh conflict and the 1988 earthquake in northwestern Armenia construction was halted. The tunnel was inaugurated on 26 April 2004. The Vorotan–Arpa tunnel brings an additional to the lake annually.