 It freezes up in November and stays icebound in April.The town of Troitsk and three reservoirs (the largest being Troitsk Reservoir) are situated on the Uy.It rises in the southern Ural Mountains east of the headwaters of the Ural between Chelyabinsk and Magnitogorsk and flows east with many meanders past Troitsk to meet the Tobol near Zverinogolovskoye (formerly the fort of Ust-Uysk).