Heavy Rain In Nepal Leads To Breach In Embankment Of Gandak In Bihar, Pg9

Key Highlights:

• Heavy rainfall in the Nepalese catchment area of the Gandak River basin triggered a severe flash flood.
• The Gandak embankment breached at Bagaha, Bihar, threatening downstream districts in Bihar and Uttar Pradesh.
• A massive discharge of 5,43,500 cusecs was recorded at the Valmikinagar Gandak Barrage.
• The river established a new Highest Flood Level (HFL) of 91.25 meters at the Bagaha gauge site, surpassing the previous 2024 record.
• Critical breaches occurred at three sites, including two in West Champaran, Bihar, and one in Kushinagar, Uttar Pradesh.
• The Water Resources Department and district administrations have mobilized teams for emergency repairs and continuous monitoring.

Gandak Flood.jpg

Detailed Insights:

• The Gandak River, also known as Narayani in Nepal, is a significant transboundary left-bank tributary of the Ganga River, originating in the Himalayas.
• The Valmikinagar Gandak Barrage, located near the India-Nepal border in West Champaran, was constructed under the 1959 Gandak Agreement between India and Nepal.
• Its primary functions include regulating river flow, providing irrigation to Bihar, Uttar Pradesh, and Nepal, and generating hydroelectric power.
• During the recent event, the river maintained a discharge exceeding 500,000 cusecs for 13 hours and over 400,000 cusecs for 32 hours.
• The breaches occurred at Khairatwa and Phuliyakhar villages in West Champaran, Bihar, and on the right bank in Kushinagar district, Uttar Pradesh.
• Flood management in Bihar is challenged by its geographical vulnerability, high sediment load in rivers, and the transboundary nature of several major rivers.
• Effective transboundary flood management necessitates cooperation between India and Nepal, as facilitated by existing frameworks like the Gandak Agreement.
• Bihar's flood control strategies involve structural measures like embankment construction and maintenance, alongside non-structural measures such as flood forecasting and disaster preparedness.

Key Concepts Involved:

• Flash Flood: A sudden and rapid flood in a low-lying area, typically caused by intense rainfall.
• Embankment: A protective wall or bank, usually made of earth, built to prevent a river from overflowing its banks.
• Cusecs: A unit of flow rate, representing one cubic foot of water per second, used to measure the discharge of water.
• Highest Flood Level (HFL): The maximum water level recorded at a specific location during a flood event.