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
Kaljani River Kaljani River Kaljani River () is a tributary of Torsha river, originated (26°50'24"N 89°26'28"E) in Bhutan at the foothills of the Himalayas and it flows from north to south via Bhutan & India and confluences (26°16'25"N 89°35'01"E) with Torsha river that again confluences with Brahmaputra river which confluences with Padma river that merges with Bay of Bengal. Kaljani river and its tributaries are attractions of the Dooars[] Major tributaries of Kaljani are Dima, Nonai, etc. The major portion of the river flows through the Indian state West Bengal. In 1993, towns like Alipurduar, Hamiltanganj on its bank was flooded when