Kak (Ulken Kak)
Kak, also known as Ulken Kak, is a lake in Timiryazev District, North Kazakhstan Region, Kazakhstan.
The southern shore of the lake lies very close to the border with Kostanay Region. Timiryazevo town, the administrative center of the district, lies to the northeast of the lake.
Geography
Kak lies in a shallow depression to the west of the Ishim, in an area of scattered lakes at the southern limits of the West Siberian Plain. The lake is roughly oval, has very little depth and its bottom is flat. The middle of the lake has a maximum depth of only about and is surrounded by a wide zone of clayey shoals. Its main food is snow and the level of the water is subject to seasonal changes, shrinking by 20 to 40% in years of drought. The water of the lake is fresh and soft, with a mineralization between and.The lake is also known as "Big Kak" in order to differentiate it from Kak "Little Kak" lake, located to the ENE in the same district.