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-class river monitor her conning tower, gun turrets and cupolas were thick. During World War II, "Besarabia" was armed with two 120 mm L/45 naval guns, three 120 mm L/10 naval howitzers, two 47 mm quick-fire guns and four machine guns. She also had a range of 690 nautical miles, more than enough to travel across the greatest East-West extent of the Black Sea, which was 635 nautical miles (the Black Sea was the area of operations of the World War II Romanian Navy). Enns-class river monitor The "Enns"-class river monitors were built for the Austro-Hungarian Navy during the mid-1910s. The two ships