Sevan Lake Problem in Water Resources Regional Management

Levon Chilingaryan, Boris Mnatsakanyan, Kamo Aghababyan

Institute of Water Problems and Hydraulic Engineering, Yerevan, Armenia
e-mail: chakopian@ysu.am

Abstract

Sevan is the biggest natural reservoir in Armenia (RA) and in South Caucasus, one of the biggest mountain lakes in the world. The problem of the lake appeared in last century due to usage of its water resources for irrigation and power production, and this problem was partly solved. There is Sevan-Hrazdan hydro-economic complex, which includes a cascade of hydro-power plants (with total capacity of 556 MW) constructed on Hrazdan River, which flows out of Lake Sevan. The complex also includes irrigation systems for 80’000 hectares of lands in Ararat Valley.
The first scheme for the problem solution included use of age-old water resources of the lake. For protection of the lake and rehabilitation of its ecological balance some measures have been implemented to stop the water level drop and for its further partial increase. The problem of the lake took on a new significance in aspects of its ecosystem and water quality rehabilitation, protection and complex usage of water resources of the lake and the whole region.
In hydro-economic aspect the new scheme includes the accomplishment of new tasks: replacement of energy production by special drawdowns of water from the lake; water stock replenishment with the purpose of providing the irrigation drawdowns and ensuring the water level increase. The latter task was accomplished by transferring into the lake the water of adjacent basins’ rivers.
Such solution brings the problem onto the regional level significance, as the growth of water level of the lake - together with its ecosystem rehabilitation – allows creating a strategic water stock, a reserve of clear fresh water for the region water supply as well as the reserve water volume for production of regulated and guaranteed energy of high quality. Currently the water level grows, thus creating the prerequisites for accomplishment of afore mentioned tasks in corresponding integrated management of water resources of the lake and the whole region.
With the purpose of solving the problem of the lake a big complex of works is implemented in studying of resource forming features, water regime and balance in the lake and adjacent basins, in development of scientific basis of redistribution and regulation of local water flow, in effective use of drawdowns from the lake. Currently a complex program of measures is running, aimed at rehabilitation and protection of the lake's ecosystem, reproduction and use of its natural resources. There is a law about Sevan Lake currently in force, which is a serious guarantee for program implementation in practice. At the same time many tasks need revision, re-understanding and correction to find new, more effective solutions.
The aforementioned considerations are related to the key question of the growth of water level of the lake. It is to finally define the optimal level of water increase, to develop the accompanying and after-increase tasks related to the use of the aforementioned reserves. And, what is most important, the scientific basis for technical policy of further handling of the issue of the lake must be developed considering the regional management of water resources.