The Sviyaga is a river in the Ulyanovsk Oblast and Tatarstan, a right tributary of the Volga. It is 375 kilometres long, and its drainage basin covers 16,700 square kilometres. The Sviyaga flows into the Sviyaga Cove of the Kuybyshev Reservoir, west of Kazan. It freezes up in November or December and stays icebound until April or May. Major tributaries ar…The Sviyaga is a river in the Ulyanovsk Oblast and Tatarstan, a right tributary of the Volga. It is 375 kilometres long, and its drainage basin covers 16,700 square kilometres. The Sviyaga flows into the Sviyaga Cove of the Kuybyshev Reservoir, west of Kazan. It freezes up in November or December and stays icebound until April or May. Major tributaries are the Arya, Birlya, Bula, Karla, Kubnya, Sulitsa and Tosha rivers.