Nura (river)

The Nura is a major watercourse of northeast-central Kazakhstan. It is long and drains an area of.

Course

The river rises in the Kyzyltas mountains, 4 km south of Qarakolboldy, which is a subrange of the Kazakh Uplands and flows initially north-northwestwards for about. It then turns to the west and flows in that direction for, then southwest for. The Nura turns north near Esengeldi for about, eventually turning southwest as it draws close to Astana, near the river Irtysh. From there, it flows southwest for almost through a series of lakes, including Sholakshalkar and Korgalzhyn, finally ending in the endorheic Lake Tengiz. The river's largest tributaries are the Sherubainura, Ulken Kundyzdy, Akbastau and Ashchysu. It is heavily used for irrigation and municipal water supply. The average discharge at the mouth is.
The Irtysh–Karaganda Canal crosses the Nura at, in what appears to be a tunnel. Some of the canal's water is directed into the Nura, replenishing this river.
The Samarkand Reservoir is constructed on the Nura downstream from the canal crossing, providing a waterfront for the city of Temirtau.

In 1972, an acetaldehyde factory in the city of Temirtau began to discharge large quantities of mercury 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 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 downstream and during high water, contaminants are spread all over the floodplain, creating a widespread problem. There is an estimated of contaminated soil surrounding the site. Ash from coal-fired power plants also pollutes the river.