Why in news? Nepal and India have agreed to reduce the height of the proposed Saptakoshi High Dam

Highlights:

• Height reduction mainly concerns in Nepal over the potential inundation of a large swathe of land upstream of the dam.
• The proposed hydropower generation from the multipurpose project will also decrease. The project is now expected to generate around 2,300MW, down from the earlier proposed 3,000MW.
• Reduction in dam height is mainly due to planned large storage hydropower projects in the tributaries of the Saptakoshi-Tamor, Sunkoshi and Dudhkoshi that regulate the water flow

About Saptakoshi High Dam

• It is also called Koshi High Dam
• Multipurpose project proposed to be constructed on the Saptakoshi River of Nepal.
• Aim: To control floods in south-east Nepal and northern Bihar of India, and to generate hydro power.

About Kosi River

• It is a transboundary river flows through China, Nepal and India.
• Source: Sun Kosi, Arun and Tamur Rivers form Saptakoshi
• It is the 3rd largest tributary of the Ganges by water discharge after Ghaghra and Yamuna.
• Kosi River is known as the “Sorrow of Bihar” as the annual floods affecting rural economy

Tributaries:

• Dudh Koshi, Likhu Khola, Tamakoshi River, Bhote Koshi, and Indravati.
• Kamala and Bagmati (Kareh) are the major tributaries of Kosi River in India

Catchment

• It covers six geological and climatic comprising the Tibetan plateau, the Himalayas, the Himalayan mid-hill belt, the Mahabharat Range, the Siwalik Hills and the Terai.

Kosi barrage

• It is also called Bhimnagar Barrage, was built between Indo-Nepal border.
• Project aims for irrigation, flood control and hydropower generation project on the Kosi River built under a bilateral agreement between Nepal and India
• The entire cost of the project was borne by India.

Biodiversity

• Sagarmatha National Park and Koshi Tappu Wildlife Reserve two protected areas are located in the Koshi River basin

Cultural Significance 

• The Kosi was also called Kausika in Rigveda.
• This river is mentioned in the epic ‘Mahabharata’ as Kausiki.