Sebezhsky District in the context of Cibla municipality

The Velikaya (Russian: Вели́кая) is a river in Novosokolnichesky, Pustoshkinsky, Sebezhsky, Opochetsky, Pushkinogorsky, Ostrovsky, Palkinsky, and Pskovsky Districts of Pskov Oblast, as well as in the city of Pskov in Russia. It is the largest tributary of Lake Peipus and belongs to the drainage basin of the Narva. It is 430 kilometres (270 mi) long, and the area of its basin 25,200 square kilometres (9,700 sq mi). The name of the river literally means "Grand" or "Great" in Russian. The towns of Opochka, Ostrov and Pskov are located on the banks of the Velikaya. The principal tributaries of the Velikaya are the Alolya (right), the Issa (left), the Sorot (right), the Sinyaya (left), the Utroya (left), the Kukhva (left), the Cheryokha (right), and the Pskova (right).

The source of the Velikaya is located in the Bezhanitsy Hills in the northwest of Novosokolnichesky District. The river flows south through a system of lakes to Lake Veryato, where it turns west. It accepts the Alolya from the right and gradually turns north, passing through the town of Opochka. Northwest of the urban-type settlement of Pushkinskiye Gory it turns west, accepts the Sinyaya from the left and turns north. In the city of Pskov the Velikaya accepts the Pskova from the right and turns northwest, forming a river delta as it enters Lake Peipus.

Pustoshkinsky District (Russian: Пусто́шкинский райо́н) is an administrative and municipal district (raion), one of the twenty-four in Pskov Oblast, Russia. It is located in the south of the oblast and borders with Bezhanitsky District in the north, Novosokolnichesky District in the east, Nevelsky District in the south, Sebezhsky District in the west, and with Opochetsky District in the northwest. The area of the district is 1,870 square kilometers (720 sq mi). Its administrative center is the town of Pustoshka. Population: 9,379 (2010 census); 12,071 (2002 Census); 14,063 (1989 Soviet census). The population of Pustoshka accounts for 49.2% of the district's total population.

Opochetsky District (Russian: Опо́чецкий райо́н) is an administrative and municipal district (raion), one of the twenty-four in Pskov Oblast, Russia. It is located in the southwest of the oblast and borders with Pushkinogorsky District in the north, Novorzhevsky District in the northeast, Bezhanitsky District in the east, Pustoshkinsky District in the southeast, Sebezhsky District in the south, and with Krasnogorodsky District in the west. The area of the district is 2,028.9 square kilometers (783.4 sq mi). Its administrative center is the town of Opochka. Population: 18,673 (2010 census); 23,973 (2002 Census); 28,877 (1989 Soviet census). The population of Opochka accounts for 62.1% of the district's total population.

The Sinyaya (Russian: Синяя, Belarusian: Сінюха, Latvian: Zilupe) is a river in Verkhnyadzvinsk Raion of Vitebsk Region of Belarus, in Zilupe, Ludza, and Cibla municipalities of Latvia, and in Sebezhsky, Krasnogorodsky, and Ostrovsky Districts of Pskov Oblast in Russia, part of the Baltic Sea basin. It is a left tributary of the Velikaya River. It is 195 kilometres (121 mi) long, and the area of its basin 2,040 square kilometres (790 sq mi).

Its source of the Sinyaya is Lake Osveya, Belarus, close to the place where the borders of Belarus, Latvia and Russia meet. After a short stretch it flows along the Belarus-Latvia border, then turns north and makes the Latvia-Russia border. It further departs from the border into the Latvian side, and flows through the town of Zilupe. North of Zilupe, it returns to the border. Even further north, the river turns northeast and enters Russia. It flows through the urban-type settlement of Krasnogorodsk and turns east in the selo of Venyavino. The mouth of the Sinyaya is in the village of Ustye.