Four hundred million people--if it were a country, it would be the third largest in the world--rely on the Ganges River and its tributaries for their livelihood. Six thousand rivers provide a perennial source of irrigation and power to one of the world’s most densely populated and poorest areas. The Himalayas, “the water tower of the Ganges,” provide 45 percent of the annual flow. These facts represent the potential payoffs to the populations of Bangladesh, India and Nepal as well as the threat that climate change poses to poor and already vulnerable people of these countries.
A recent visit gave me a clear picture of both the potential and risks of this mighty river system. Regulating water through reservoir storage in Nepal could potentially lower flood peaks and prevent the worst flood shocks in its own lowlands, the northern Indian states and Bangladesh. Nearly fifty million farmers could benefit from higher dry-season flows. Estimated conservatively, Nepal sits on a hydropower resource of 83,000 MW. Meanwhile, its southern neighbor India, growing at over 8 percent a year, is thirsty for clean energy.
In the Rolwaling Valleyabout 20 miles southwest of Mount Everest, I made an aerial tour of Tsho Rolpa, the largest glacial lake in Nepal, formed over the last 40 years as the Tarkarding glacier stagnated, melted and retreated. At about 15,000 feet, the lake, which is over two miles long and up to 500 feet deep, continues to expand. An unstable natural moraine dam retains the lake. The current risk is high that the dam will burst. A catastrophic out flow will occur, devastating villages, farmlands, infrastructures and taking thousands of lives downstream. This tour provided us with a harsh reminder that the Himalayas contain the largest body of ice outside the Polar Regions but also present the fastest glacier retreat of any mountain range, with potentially catastrophic consequences for the region, in particular in the dry season.
From Tsho Rolpa, we flew south along the Tama Koshi River to Kirne where we toured the Khimti Hydropower Plant. A relatively environmentally-friendly project, it is a “run of the river” scheme--there is no dam at the intake, the technology is quite impressive, and the entire operation is run by a control room operated with a supervisor and operator (no personnel inside the power plant). The power plant contains five turbines that generate a combined 60 MW of electricity. A whole community lives on site, with a private school, a clinic, and a fire department. The school has about 430 students, of which 130 are children of the plant’s employees and the rest are from the local community. All classes are taught in English, and the school has recently expanded through grade 10.
From Kirne, we followed the Tama Koshi River south to the Koshi barrage. Built in 1964, the purpose of the barrage is to provide irrigation through manmade canals to India and Nepal (through the Western Koshi Main Canal). India built the barrage on Nepali territory under a treaty signed in 1954 and still controls the opening of the 56 gates during the rainy season.
As David Grey, the World Bank’s Senior Adviser on Water Resource Management points out, Nepal’s water assets are unique and world-class. It needs world-class capacity to manage them, so the country can have domestic prosperity, peace and growth. Nepal is also the linchpin to regional cooperation and benefit-sharing, something that has eluded South Asia--the least integrated region of the world--in the past. Perhaps climate change can provide the much-needed trigger to opening this dialogue.
The well-being of four hundred million poor people is at stake. Helping Nepal, Bangladesh and India develop this river basin for improved power, irrigation and disaster management is one of the most exciting challenges of my career.
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