Abstract
The ecological condition of an ecosystem of the lake Sabyndykol is analysed, the hydrological and hydrochemical characteristic of a reservoir is given. Biological diversity of phytoplankton, phytobenthos, zooplankton, zoobenthos, fish fauna, coastal and water vegetation is revealed. Ground deposits of lake ecosystem are considered. The processes of instruction and shallowing of a reservoir which have amplified recently are considered. It is proved that the drain of flood and storm waters from the nearby settlement leads to water pollution. The cattle grazing on the lake coast promotes violation and destruction of coastal vegetation. Practical recommendations of nature protection character are suggested.