ITAHARI: In every monsoon, the Koshi Barrage comes into the national limelight for the rising water level and possible alertness and danger associated with it.

With 56 sluice gates to regulate water, the 1150-metre-long and 10-metre-wide Barrage connecting Sunsari of State-1 and Saptari of State-2, has an interesting story before its construction of 1959 and operation of 1962.

As the biggest river of Nepal and its character as transnational glacier-fed river, Koshi is an interesting topic to both Nepal and India. Koshi Barrage is also an integral part of this holy river for Hindus.

Here are nine facts of the Koshi Barrage of Nepal.

One of the four major ideas to control floods of Bihar of India

Koshi is known as the ‘sorrow of Bihar’ as flood wreaks havoc in the Indian state.

Barrage was a product of multiple ideas to control monsoon floods in India’s Bihar State.

Along with construction of the embankment, digging of canals at Nepal and Bihar, construction of hydropower project of 12 thousand kilowatts, Indian side conceptualized Koshi Barrage at Bhimnagar of Nepal to control floods at Bihar.

According to a Documentary titled ‘Kosi’ directed by Mahesh Chunawala, Central Water and Power Commission of India made a six-year-long study and approved these four ideas to ‘tame’ Koshi.

Koshi taming was also a result of 1953 devastating flood in Bihar. The then Prime Minister of India Jawaharlal Nehru visited the affected areas and promised to float a ‘Koshi Scheme’ to embank nearby 150 kilometres of the river from near the base of the Himalayas in Nepal to near its confluence with the Ganges in Bihar, said an article co-authored by Peter Gill and Bhola Paswan in the thethirdpole.net.

Just a year later to this commitment, Nepal and India inked Koshi Agreement on 25 April 1954.

South Asia’s biggest river project at that time

Koshi Barrage was the biggest water project at the time of its construction, according to a journal article titled ‘The Bihar Flood Story’ written by Dinesh Kumar Mishra, an Indian engineer, in the Economic and Political Weekly in 1997.

Mishra said technicians were taken to visit Mississippi of USA and Yellow River of China to make observation of the similar project as such projects were not found in South Asia.

Jointly inaugurated by the then king of Nepal and PM of India

On 30 April 1959, the then king Mahendra and independent India’s first Prime Minister Jawaharlal Nehru laid Koshi Barrage’s foundation.

At the formal function, thousands of people were present at Bhimnagar, the construction site of the project.

One million plus people involved at the construction site

The mega project was in mega scale on the human resources front also. Based on the 10:36-minute-long ‘Kosi’ documentary, 1 million and 20 thousand people were involved at the project site.

The documentary said, the estimated cost of the project was 500 million Indian Rupees.

Use of ropeways and trams

In order to ferry large quantity of earth and boulders, ropeways and trams were used. Tram from Dharan to Bhimnagar and ropeway from Fusre to Railway of Dharan were operated to transfer boulders.

Railway Chowk of Dharan was coined after the use of tram at the area. No trams and ropeways are found these days.

However, the first use of trams and ropeway in the State-1 and 2 is linked to this legacy.

Two different agreements of Koshi

In order to manage Koshi and construct Koshi Barrage, Koshi Agreement was first made on 25 April 1954.

However, in order to amend it, another agreement was made on 19 December 1966.

It was signed during the premiership of Matrika Prasad Koirala. Based on this agreement, some new provisions including 199-year-long lease to India was inked.

Expired barrage

There is no exact date of the expiration of Koshi Barrage in public domain.

Based on Indian media reports, Koshi Barrage has outlived its stipulated lifespan.

However, the Indian media have varied dates of the barrage’s expiry date. For example, in a report published in the Financial Express, it is said lifespan of the Koshi Barrage is 27 years.

But, another report published by The Times of India said the lifespan of the Koshi Barrage is 30 years.

Whatever the reports, the 58-year-old Koshi Barrage has outlived its lifespan.

Barrage to withstand highly destructive and large silt-carrying river

Koshi is an unpredictable river. And, the Koshi Barrage has to withstand the triple pressure of shifting river, large volume of silt and floods.

Some researchers say Koshi River has shifted 115 kilometres west in the last 200 years.

Likewise, the erosion rate of Koshi is also high. According to a journal article penned jointly by authors trio- K.R. Kafle, S.N. Khanal and R.K. Dahal for the Kathmandu University’s Journal of Science, Engineering and Technology, which was published on August 2015, erosion rate of Koshi at Barahakshetra area is 169 ton/ha/yr.

Koshi is also a river carrying large volume of silt. According to a report titled ‘Understanding Sediment Management’ carried out by the International Center for Integrated Mountain Development (ICIMOD), Koshi has ‘exceptionally high sediment carrying capacity.’

According to the report, Koshi accommodates just nine per cent of water to Ganges river but represents 25 per cent of its total sediment.

The report said Koshi carries 100-135 million tons of silt in a year. According to Dr Santosh Kumar, the former professor of Water Resources at N.I.T. Patna of India who has widely researched on Koshi, the Koshi Barrage is designed to withstand 954,000 cusecs of waters.

However, the deposited silt on the river has made it easy to pressure barrage. For example on 18 August 2008, there was embankment breach at Kusaha of Sunsari causing heavy floods to southern Sunsari of Nepal and northern Bihar at a time when the water volume was just around 148,322 cusecs.

The volume of Koshi waters during monsoon goes five to ten times higher than during the dry-season, says a report titled ‘Avulsion threshold and planform dynamics of the Koshi River in north Bihar and Nepal: A GIS framework’ which is written by R. Sinha, K. Sripriyanka, Vikrant Jain and Malay Mukul.

A hub of highway and hangout

Koshi Barrage is not limited within flood regulation. It is also a hub of national highway and a popular hangout.

The East West highway passes through this barrage. Before the inauguration of the Chatara-Belaka bridge over Koshi river on 3 August 2015 by the then Prime Minister Sushil Koirala, Koshi Barrage was the sole section to cross Koshi River for the vehicles.

Despite the construction of the New Koshi Bridge located at 52-kilometres upstream the Koshi Barrage, the barrage is still a busy section of vehicular movement of East-West Highway.

Besides its importance as the part of Nepal’s national highway, Koshi Barrage is a popular hangout for travelers, both Nepalis and neighboring Indians from Bihar.

Daily, dozens of people frequent to this place for clicking pictures, making videos and having fun, with the locally available fishes at the nearby eateries around the barrage area.