Songhua River

The Songhua or Sunghwa River (also Haixi or Xingal, Сунгари Sungari) is one of the primary rivers of China, and the longest tributary of the Amur. It flows about 1,897 km from Changbai Mountains on the China–North Korea border through China's northeastern Jilin and Heilongjiang provinces.

The river drains 557,180 km2 of land, and has an annual discharge of 76.2 km3/year to 81.77 km3/year.

The extreme flatness of the Northeast China Plain has caused the river to meander over time, filling the wide plain with oxbow lakes, as remnants of the previous paths of the river.

Geography
The Songhua rises south of Heaven Lake, near the China-North Korea border.

From there it flows north, to be interrupted by the Baishan, Hongshi and Fengman hydroelectric dams. The Fengman Dam forms a lake that stretches for 62 km. Below the dam, the Second Songhua flows north through Jilin, then northwest until it is joined by its largest tributary, the Nen River, near Da'an, to create the Songhua proper.

The Songhua turns east through Harbin, and after the city, it is joined from the south by the Ashi River, and then by the Hulan River from the north.

A new dam was constructed in 2007 near Bayan (50 km northeast of Harbin), creating the Dadingshan Reservoir, which is named after the scenic area on the south bank.

The river flows onward through Jiamusi and south of the Lesser Xing'an Range, to eventually join the Amur at Tongjiang, Heilongjiang.

The river freezes from late November until March. It has its highest flows when the mountain snow melts during the spring thaw. The river is navigable up to Harbin by medium-sized ships. Smaller craft can navigate the Songhua up to Jilin and the Nen River up to Qiqihar.

Cities along the river include:
 * Jilin
 * Harbin
 * Jiamusi

History
In November 2005, the river was contaminated with benzene, leading to a shutdown of Harbin's water supply. The spill stretched 80 km and eventually reached the Amur (Heilong) River on the China–Russia border. On July 28, 2010, several thousand barrels from two chemical plants in China's Jilin City were washed away by floods. Some of them contained 170 kg of explosive material like trimethylsilyl chloride and hexamethyldisiloxane. In 2016, the part near the city of Jilin was affected by a minor flood.