[3] The upper part of Nizhnyaya Tunguska is 580 kilometres (360 mi) long and follows a wide valley with flat slopes that was formed by sand and clay deposits.

The average annual discharge of the Kochechum is 600 cubic metres per second (21,000 cu ft/s), and its basin covers nearly 100,000 square kilometres (39,000 sq mi).

The river has no big lakes in its basin; the biggest is Vivi with a surface area of 229 square kilometres (88 sq mi).

According hydrological observations during 52 years, the minimum average monthly discharge was 27.8 cubic metres per second (980 cu ft/s) in March 1969—it was exceptionally dry winter—and the maximum value corresponds to June 1959 and was 31,500 cubic metres per second (1,110,000 cu ft/s)[7] The diagram below contains mean values of monthly average discharges calculated on the base of a 52-year-long period of observations at hydrological station "Bolshoy Porog" (фактория Большой Порог, Bolshoy Porog factory).

The summer break-up and drifting of ice passes very violently; it leaves traces in the form of torn-apart uprooted trees and polished rocks.

[3] During some days of spring freshets the river's discharge can peak at 74,000 to 112,000 cubic metres per second (2,600,000 to 4,000,000 cu ft/s), and it supplies 50 to 60 per cent of the water volume to the lower stream of the Yenisey in the time of its seasonal inundation.

The channel of Nizhnyaya Tunguska with its tributaries constitutes dense network of rivers and creeks which creates convenient summer pathways through the wide rifted valley of Eastern Siberia.

The passage of large ships and barges is possible during the spring inundation, and rainy weather during particular years allows short periods of navigation at the end of summer or the start of autumn.

As of 2010 the shipping routes of Yenisey River Steamship Lines (Russian: Енисейское речное пароходство) includes the village Kislokan, 1,155 kilometres (718 mi) from the estuary.

It was suggested (and some research was done) in 1911 to build a canal joining the Lena and Nizhnyaya Tunguska rivers in the neighbourhood of Kirensk.

After completion of this project Nizhnyaya Tunguska will be dammed, flooding about 10,000 square kilometres (3,900 sq mi) of forest and tundra (roughly the size of Lebanon or the islands of Hawaii), some of which contains buried nuclear waste, and displacing the indigenous Evenk population.

The plant will be built and operated by RusHydro in the Krasnoyarsk region, and the electricity will be channeled to European Russia via a 3,500-kilometre (2,200 mi) system of power lines.