Through the Tisa and Danube rivers, it belongs to the
Black Sea catchment basin. Its own catchment area is . In the 17th century, the river was used for the transportation of wood and for the draining of the surrounding marshy lands. After the 1718
Treaty of Passarowitz when the
Habsburg monarchy acquired the Banat area, new Austrian authorities began concurrent construction of two parallel channeled flows. One included the channeling of the
Bega Veche or Stari Begej. Originally long, today it is a bit shorter and is actually a tributary to the Bega. It is mostly used for draining. The second channel is the modern Bega flow, previously known as the Navigable Begej. It included the long section between Timișoara (now in Romania) and Klek (now in Serbia). The river was previously used for dumping of the wastewater. Four complexes of
locks-
sluices were built from 1910 to 1912 which allowed for constant navigation, regardless of the periods of low water levels. Today two are in Romania (
Sânmihaiu Român,
Sânmartinu Maghiar) and two are in Serbia (Itebej, Klek). It was navigable for ships up to 500 tons. Also, floods were regulated, too. Due to the lack of proper maintenance, the Serbian section of the channel stopped being navigable in 1958. Due to the deteriorating state of the locks, even the recreational sailing was banned so the water was used only for irrigation and for supplying the fishponds. Works on the
marina and an anchorage in Zrenjanin began in the summer of 2019, concurrently with the construction of the bicycle path to the Romanian border. As the works began in 2019, the deadline was moved to 2023, but the anchorage should be finished by 2022. Additional works includes the cleaning and revitalization of the river itself. By 2019, Romanian part of the river was completely cleaned, as the problems with the pollution were solved, partially due to the shut down of the dirt industries and partially because of the implemented treatment of the waste. On Serbian side, nothing has been on the pollution prevention and the major sources of pollution are the town of Zrenjanin itself and the Ečka fishponds, which also polluted the nearby Carska Bara nature reserve. Settlements on Begej include the villages of
Srpski Itebej (with a huge fishpond),
Novi Itebej,
Torak (formerly Begejci) and
Žitište. ==Tributaries==