Nera (Danube) basin and it is not navigable. After the filling of the artificial Lake Đerdap, as a result of the Iron Gate I Hydroelectric Power Station which was finished in 1972, the mouth of the river into the Danube was flooded. In order to allow the optimal electricity production, the water level of the Nera at the mouth should not go below , while it must not exceed it if the flooding of the banks is to be avoided. Since the mid-1990s, there are significant problems in fixing the river's level, as the process is costly and complicated. In 2018, representatives
Enns (town) Enns (town) Enns is a town in the Austrian state of Upper Austria on the river Enns, which forms the border with the state of Lower Austria. Enns was one of the first places in Austria to receive town privileges. The town charter dates to 22 April 1212, the document is displayed at the local museum. The date is also depicted on the Town Tower, the landmark of Enns. Enns extends for 7.5 km from north to south and 8.6 km from west to east. Its total area is 34.3 km², of which 12.8% are covered with forest, and 64.1%