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
Kobuk River Beaver Creek, Mauneluk River, Kogoluktuk River, Shungnak River, Ambler River, Akillik River, Tutuksuk River, Salmon River, and the Squirrel River. Within Kobuk Valley National Park, are the Kallarichuk, Kaliguricheark, and Adillik rivers. All of their headwaters are in the Baird Mountains. The major tributaries flowing north from the Waring Mountains are the Pah River, Pick River, and Niaktuvik Creek. The Pah River drains a lowland area of the basin. Most major tributaries draining high relief areas have higher unit runoff than tributaries draining the lower relief areas. Walker Lake is at an altitude of in the headwaters of the Kobuk