Balasan river

News: Recently, heavy rains caused landslides and flooding in the Darjeeling hills, damaging roads and infrastructure, including the collapse of the Dudiya iron bridge over the Balasan river.

About Balasan River

• It is a perennial river flowing in the Darjeeling District of West Bengal.
• Origin: It originates from Lepchajagat on the Ghum-Simana ridge at an altitude of about 2,361 m in the Darjeeling Himalayas, below Tiger Hill.
• Naming: The name ‘Balasun‘ is derived from the Lepcha language, highlighting local heritage.
• The main course of the Balason River flows from north to southeast for approximately 51.92 km.
  
• The river basin spans parts of Rangli Rangliot, Naxalbari, Matigara, Jorebunglow Sukiapokhri, Mirik, and Kurseong in the Darjeeling district of West Bengal.
• Tributary of: It is a major right-bank tributary of the Mahananda River, joining it at Noukaghat, near Siliguri.
  • The Mahananda River eventually merges with the Ganga river system.
• Right-bank tributaries: Pulungdung Khola, Rangbang Khola, Marma Khola, Manjwa Jhora, and Dudhia Jhora.
• Left-bank tributaries: Bhim Khola, Rangmuk Khola, Pachhim Khola, Rinchigtong Khola, and Ghatta Hussain Khola.
• Drainage pattern: The drainage network exhibits a dendritic pattern and river valley is characterised by a steep, ungraded channel, narrow valley floor, and steep valley sides.
• The basin area is largely composed of intensely metamorphosed rocks, including gneiss, slates, phyllite, and schists and are basin area is dominated by Inceptisol soils.