Within the park area, Mureş is 88 km long and 120 m wide on the average, the last part of it, from Nădlac to Cenad, being the border between Romania and Hungary. In time, it has undergone a series of natural changes, but, unfortunately, also many artificial ones determined by people. 
The mean annual discharge of the Mureş River is of 184 m3/s. The maximum discharges of the river can reach over 2,000 m3/s (2,330 m3/s during the flood from 1975, for example). But the use of its waters is restricted by their quality and by the fact that the river here approaches the end of the drainage area, gathering pollutants which make it useful only for industry and agriculture. Still, in this sector the river Mureş has improved its quality parameters in the last years.