Uy River (Tobol basin)
The Ui (Russian Уй ) is a 462 km long left tributary of the Tobol east of the Urals, in the southwest of the West Siberian Plain in Russia and along the border with Kazakhstan.
He is not to be confused with the same name, right tributary of the Irtysh Ui, also in West Siberia.
The Ui rises in about 700 meters above sea level on the eastern flank of here good 1000 meters high Southern Urals, about 50 kilometers southwest of the city Miass. The source and the headwaters of the river are in the Republic of Bashkortostan. First, the Ui flows in a southeasterly direction over the Transuralplateau ( Sauralskoje plato ), reached the Chelyabinsk region and then turns to the east. From the city of Troitsk, the river forms to wide sections of the border between Russia and Kazakhstan, the last 50 kilometers of the mouth into the Tobol the village Ust- Uiskoje the border between the Russian Oblast Kurgan and Kazakhstan.
The catchment area of 34,400 km ² comprises Ui. The average monthly water flow is at about 60 km above the mouth situated village Krutojarski 13.5 m³ / s ( minimum in February, 1.7 m³ / s, maximum during snowmelt in April 61 m³ / s).
The largest tributary is the Uwelka, which opens from the left in Troitsk in the Ui. Above the last kilometer before the mouth, on which widens the river, it is about 30 meters wide and two meters deep; its flow rate: 0.4 m / s
The Ui freezes from November to April.
Economy and infrastructure
The Ui is not navigable. In its course, there are three smaller reservoirs that provide drinking water and irrigation. Largest Dam is the Troizker dam with an area of 10.8 km ², which serves inter alia as a cooling water reservoir for the Troizker thermal power plant.
In the upper reaches of the Ui of the railway Miass - Utschaly is crossed in Troitsk from the main route Chelyabinsk - Orsk or - Qostanai (Kazakhstan). In Troitsk the highway M36 from Chelyabinsk Yekaterinburg on the Kazakh border crosses the river.
In the largest part of its course the Ui is accompanied by regional and local roads.