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) which up to 6,000 soldiers were stationed, was located on the site of modern Enns. The adjacent settlement (today: "Lorch") received the privileges of a "municipium" in 212 from Emperor Caracalla. At that time about 30,000 people lived here. During the Diocletian Persecution of Christians, a commander of the Roman army, Saint Florian, died as a martyr at "Lauriacum" on 4 May 304, when he was drowned in the Enns river. Only nine years later, the Emperor Constantine I proclaimed religious tolerance with the Edict of Milan. About 370, an Early Christian basilica was built on the remains of a