of flow here grow to . The channel and water flow of the river's lower stream has its own distinguishing features, which can be seen in some places at Nizhnyaya Tunguska, including the following: The strips of stones with sizes , which stretch near water along the shore line. This peculiar feature of Arctic stony rivers with the local name "bechevnick" is formed during every period of ice drift and river inundation at spring. At some locations these sorts of pebbles are polished and pressed together to the extent that they create a cobbled road of their own kind. The slopes of the river canyon during its evolution underwent stone avalanches that formed stone runs of individual rocks as big as in diameter. These slide-slopes have a local name, korga, and create zones of calm backwater downstream. The stream in the channel of the Lower Tunguska sometimes forms whirlpools. They originate downstream of cliffs which channels flow to the opposite shore. These whirlpools can reach depths to and occur most often during high-water periods in early summer. Tributaries The most significant tributaries of Nizhnyaya Tunguska are the rivers entering from the right: Yeyka, Kochechum, Yambukan, Vivi, Tutonchana, Erachimo, and Severnaya. Entering from the left are the Nepa, Bolshaya Yeryoma, Teteya, Ilimpeya, Nidym, Taymura, and Uchami. The most prominent tributary is Kochechum, which joins the main stem from the north near Tura. The average annual discharge of the Kochechum is , and its basin covers nearly . On the whole, the right tributaries of Nizhnyaya Tunguska dominate over the left and add more water. The river has no big lakes in its basin; the biggest is Vivi with a surface area of . Inflows to the Nizhnyaya Tunguska are strongly seasonal. Hydrology The value of average water discharge of Nizhnyaya Tunguska gives it eleventh place amongst largest rivers of Russia. The annual water discharge at the river's mouth is equal to . The minimum value observed in 1967 was ; the maximum was in 1974 or, respectively, for the estuary of the river it was about and about . The water supply of the river is from melting snow and summer rains. During winter season Nizhnyaya Tunguska contains little water as its basin lies in the region of permafrost and it has no subterranean water sources. According hydrological observations during 52 years, the minimum average monthly discharge was in March 1969—it