The Nura River or River Nura is a major watercourse of northeast-central Kazakhstan

Kazakhstan

Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

. It is about 978 kilometres (607.7 mi) long and drains an area of 58100 square kilometre.

Course

The river rises in the Kyzyltas Mountains and flows initially north-northwestwards for about 100 kilometres (62.1 mi). It then turns to the west and flows in that direction for 220 kilometres (136.7 mi), then southwest for 180 kilometres (111.8 mi). The Nura turns north near Isen for about 200 kilometres (124.3 mi), eventually turning southwest as it draws close to Astana near the Irtysh River. From there, it flows southwest for almost 300 miles (482.8 km), through a series of lakes, finally ending in the endorheic

Endorheic

An endorheic basin is a closed drainage basin that retains water and allows no outflow to other bodies of water such as rivers or oceans...

 Lake Tengiz

Lake Tengiz

Tengiz Lake is a saline lake in north-central part of Kazakhstan. Lake Tengiz is an important wetland site for birds. It ia a part of a Ramsar wetland site of international importance, "Tengiz-Korgalzhyn Lake System". 318 species of birds have been recorded at Lake Tengiz, 22 of which are endangered...

. The river's largest tributaries are the Sherubainura, Ulkenkundyzdy, and Akbastau rivers. It is heavily used for irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 and municipal water supply. The average discharge at the mouth is 28.39 m3/s.

Pollution

In 1972, an acetaldehyde

Acetaldehyde

Acetaldehyde is an organic chemical compound with the formula CH3CHO or MeCHO. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale industrially. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants as part...

 factory in the city of Temirtau

Temirtau

Temirtau is a city in the Karaganda region of Kazakhstan. Pop 180,000.-History:*1905, June, 15 - the first groups of settlers settled down on the left bank of the Nura River. There were 40 families, that had arrived from Samara...

 began to discharge large quantities of mercury

Mercury (element)

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

 waste into the river. Although the factory closed in 1997, large amounts of mercury remain in the river and the area around it. Most of the mercury is spread in alluvial soils for a 25 kilometres (15.5 mi) stretch from Temirtau to the Intumak Reservoir, where most of the pollution was trapped. Despite that, significant levels of mercury are still found as far as 70 kilometres (43.5 mi) downstream and during high water, contaminants are spread all over the floodplain

Floodplain

A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

, creating a widespread problem. There is an estimated 1500000 cubic metre of contaminated soil surrounding the site. Ash from coal-fired power plants also pollutes the river.