The article is devoted to the assessment of the ecological sustainability of Lake Gorkoye in the Chelyabinsk region (Russia). The condition of aquatic ecosystems in industrial regions is mainly determined by the impact on them of anthropogenic factors. The ecological assessment of Lake Gorkoye was carried out according to organoleptic and hydrochemical indicators. The conducted physical and chemical analysis of water in Lake Gorkoye allows stating that water pH characterizes water as slightly alkaline and alkaline, water saturation with dissolved oxygen is within the norm for water fishery use. The excess of the norms of ammonium cations and nitrite ions, with normal levels of phosphate and nitrate ions, suggests that water in Lake Gorkoye belongs to the dirty water class, which is confirmed by the calculated ratio of nitrite-ions and ammonium cations (1.00:9.69). The revealed COD/BOD ratio is equal to 2.09, indicating that the biological purification process cannot fully occur. Lake Gorkoye is in an unstable state directly caused by business activities in the surrounding area.