Мста
The district is located in the southern end of the Valdai Hills, on the divide separating the drainage basins of the Baltic and Caspian Seas. The rivers in the northern part of the district drain into the Msta River, a major tributary of Lake Ilmen in the basin of the Neva River and the Baltic. The Msta itself originates in the district and has its source in Lake Mstino. The principal tributaries of the Msta within the district are the Shlina, the Lonnitsa, and the Tsna. The Tsna and the Lonnitsa are technically inflows of the Vyshny Volochyok Reservoir, which has two outflows, one into Lake Mstino and the Msta, and another one into the Tvertsa River. The Tvertsa, a left tributary of the Volga River, is also the biggest river in the central part of the district. Some areas in the southwestern part of the district belong to the drainage basin of the Poved River, a right tributary of the Tvertsa. The rivers in the east of the district drain into the Volchina River, a left tributary of the Mologa, also in the Volga basin.