Kapchagay Reservoir, Hydroelectric reservoir in Almaty Region, Kazakhstan

Kapchagay Reservoir is a large artificial water body in the Almaty Region of Kazakhstan, formed by blocking a section of the former river valley. The surface extends from shallow sandy shores to areas where the water runs deep and calm.

A dam and the Kapchagay hydroelectric station were built between 1965 and 1980 in the narrow Kapchagay gorge between rock banks of the Ili, and filling began in 1970. The reservoir regulates the Ili's flow, and its water also softened the climate as far as Almaty. The dam crests measure 470 and 370 m, with heights of 50 and 56 m.

The reservoir is named after the Kapchagay gorge on the Ili, not after the dam. Its Kazakh name is Qapshağay su qoymasy. The western shore holds the town of Konaev, and the water is used for irrigation, fish farming and recreation. The prevailing westerly wind is called the Chilik; the opposite wind is the Balkhash.

The shoreline can be reached by road from the nearby city, where parking areas and basic facilities are available. In summer the site suits day trips with opportunities for swimming, while in winter the wind sweeps across the open water.

The reservoir's filling, begun in 1970, submerged the Ili riverbed and the left-bank floodplain up to the mouth of the Charyn. The dam and Kapchagay hydroelectric station were built between 1965 and 1980 in a narrow gorge between rock banks. The station's four turbine tunnels and two construction-operation spillway tunnels are cut into those rocks.