Nura (river)

The Nura (Нұра, Nura; Нура) is a major watercourse of northeast-central Kazakhstan. It is 978 km long and drains an area of 60800 km2.

Course
The river rises in the Kyzyltas mountains, a subrange of the Kazakh Uplands and flows initially north-northwestwards for about 100 km. It then turns to the west and flows in that direction for 220 km, then southwest for 180 km. The Nura turns north near Esengeldi for about 200 km, eventually turning southwest as it draws close to Nur-Sultan near the river Irtysh. From there, it flows southwest for almost 300 mi 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 28.39 m3/s.

The Irtysh–Karaganda Canal crosses the Nura at 50.09056°N, 73.37778°W, in what appears to be a tunnel. Some of the canals water is directed into the Nura (a chute below the dam at 50.09167°N, 73.37694°W), replenishing this river.

The Samarkand Reservoir is constructed on the Nura downstream from the canal crossing (the dam is at 50.10472°N, 72.91889°W), providing a waterfront for the city of Temirtau.

Pollution
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 25 km 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 km downstream and during high water, contaminants are spread all over the floodplain, creating a widespread problem. There is an estimated 1500000 m3 of contaminated soil surrounding the site. Ash from coal-fired power plants also pollutes the river.