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 grape (frequently with Nebbiolo) where it contributes acidity to the blend. Over the years Rossola nera has been known under a variety of synonyms including: Rossoladure, Rossera, Rossola and Rossolo. However, Vitis International Variety Catalogue (VIVC) managed by the Geilweilerhof Institute for Grape Breeding in Germany currently does not recognize any synonyms for the grape variety. The VIVC does list "Rossola nera" as a recognized synonym of Mourvèdre. Rossola nera Rossola nera is a red Italian wine grape variety that has been growing in the Valtellina region of Lombardy since at least the 17th century. In 2004 DNA profiling determined