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
Congo River for the lack of bridges crossing the main rivers, although there are a number of ferries available for crossing the great "Congo river" and the major tributaries. The main reasoning is the mere width of the Congo river and main rivers, and the second is the lack of funds to set up permanent river crossings, this is however slowly changing to the better. There are only two bridges on the Congo river proper and main tributaries, which both are found in the DR Congo: There is one bridge on the Uele River, and two on the Kibali River, which all