a river in Kostroma Oblast, RSFSR; a right tributary of the Unzha. The Viga is 175 km long and has a basin area of 3,360 sq km. The river originates in the Galich Upland and flows through flat country. The channel is meandering. The Viga is fed by snow and rain. It freezes in November, and the ice breaks up at the beginning of April. The river is used for floating timber.