The Soan River (Urdu: سواں), also referred to as the Swan, Sawan, or Sohan, is a river in Punjab, Pakistan.
The Soan River is an important stream of the Pothohar region of Pakistan. It drains much of the water of Pothohar. It starts near the small village of Bun in the foothills of Patriata and Murree. It provides water to Simly Dam, which is the water reservoir for Islamabad. Near Pharwala Fort it cuts through a high mountain range, a wonderful natural phenomenon called Soan Cut. No stream can cut such a high mountain, which proves that the Soan was there before the formation of this range. And as the mountain rose through millions of years, the stream continued its path by cutting the rising mountain. Ling stream, following a relatively long course through Lehtrar and Kahuta falls in the Soan near Sihala on southern side of Village Gagri/Bhandar.
Islamabad Highway crosses this stream near Sihala where the famous Kak Pul bridge is constructed over it. The Ling Stream joins the Soan river just before the Kak Pul. Two other famous streams, the Korang River joins it just before the Soan Bridge and Lai stream, joins this stream after the Soan Bridge. After following a tortuous path along a big curve, the stream reaches Kalabagh proposed Dam Site close to Pirpiyahi where it falls into the Indus river. There is a famous railway station by the name of Sohan and a beautiful railway bridge very close to it. This relatively small stream is more than 250 kilometers long. Due to its mountainous course and shallow bed, it is hardly used for irrigation purposes. There are many species of fish in this river like China Rahu, Mahasher, Snakehead, Balm and Catfish are the main species of fish in this stream and Kingfisher birds hunt here too. In addition, there are many species of tortoises and turtles. The marine life of this river has been endangered due to drainage of chemicals of Sihala Industrial State and effluent water of Rawalpindi city into it. There was a time when peoples used to fish in this stream with nets and hooks and bring home handsome catch but now, not only the above species of fish have diminished but also peoples avoid to eat Soan River's fish as it feeds on contaminated water, which can cause different diseases. Ministry of Environment must take action and treat the effluent water of Rawalpindi city before releasing it into Soan River and also punish and fine those industrialists who are releasing chemicals and other industrial waste into the river and destroying the beautiful marine life of Soan River.