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
Rossola nera bunch rot and powdery mildew. In 2000 there were 115 hectares (284 acres) of Rossola nera planted in Italy, the vast majority of it in the Valtellina region of Lombardy and extending all the way to the Swiss border. Here the grape is a minor blending component permitted to account for between 5-25% of the various "Denominazione di origine controllata" (DOC) red wines of Lombardy. In the Valtellina DOC, up to 20% of Rossola nera can be blended into the Nebbiolo-based wine (known locally as "Chiavennasca") provided the grapes are limited to a harvest yield of 12 tonnes/ha. The finished