The hydrographic network of Timisoara is very rich in rivers, lakes and swamps. Except for the rivers Bega and Timis, the other rivers often run dry during the summer period.
The main river course is the Southernmost tributary of the Tisa River. Springing from the Poiana Ruscai Mountains, the Bega River is canalized and open to navigation between the city of Timisoara and the lower Tisza (115 km). The Bega canal was built between 1728 and 1760 but its final arrangement was done later. For the regularization of the discharge in limits to permit the accomplishment of the functions which was built for, a hydrotechnical hitch was built at Costei whose main function is to regularize the discharge respectively to ensure the water transphere from the Timis River to the Bega canal according to the necessities and to the quantity of the flows of water taken upstream by the two rivers. The Bega canal has a 600-700 BTU barge tolerance and a 3.000.000 waggon annual transport capacity. In order to eliminate the flood threat, so frequent in the past, the construction work was completed later by the hydrotechnical system from Topolovatul Mic through which during the abundent stream of water period, the discharge surplus registered by the Bega River was led towards the Timis river.
From the variety of the river branches that existed before the canalization of river, there are only a few left such as the Bega Moarta (in the Fabric Neighbourhood) and the Old Bega (towards West Side, flowing through Sacalaz).
There are also numerous lakes in the area of Timisoara either natural or of anthropic origin. The natural lakes were formed in the place of old meanders or in detached areas such such as those near the Kuntz colony near Giroc, the Snakes Lake from The Green Forest and so on. The lakes of anthropic origin (towards Fratelia, Freidorf, Mosnita, Mehala, Strandul Tineretului and so on) are notable by their location right near the peri-urban localities.
Reguarding the sunterranean rivers of Timisoara, it has been ascertained that its ground-water layer lies at 0,5 to 4 m depth. The deep ground-water layers situated from 4 or 9 m to 80 m depth increase from North to South and contain drinking water reassuring in this way some of the necessary demands of the urban consumption. There are also the deepest ground-water layers found in The Unification Place (hipothermal waters) at South from the fortified town and in the Fabric Neighbourhood (mezothermal waters) with therapeutical value and with balnear purpose.
