The Himalayan region, of which Nepal is a part, stores one-fifth of the world's fresh water. It is therefore fitting that two landmark books this year on water management and regional cooperation to harness water resources should both be published in Nepal.

The first is Himalayan Waters by the Bhutanese water expert Bhim Subba and published by the communication and media training agency, Panos South Asia. The other is Water in Nepal, a collection of articles and monographs by Nepali resource economist, Dipak Gyawali and published by Himal Books. Between them, the two books have the potential to turn anyone into an arm-chair water expert. The lay reader, journalist, academic, policy makers and donors get a tour de horizon of the enormous hurdles and stupendous potential for better water management in the region and in Nepal.

The Himalaya is the fountainhead of water that sustains some 1.5 billion people. Water from the roof of the world flows down the Indus to the Arabian Sea, it flows north from the Karakoram to the Aral and the Caspian, from eastern Tibet it gurgles down the Yangtse to the Chinese heartland, it tracks down the Mekong and Irrawady to south-east Asia, and through the Ganga-Brahmaputra system it flows to the Bay of Bengal.

But despite this enormous water storage capacity, as Subba points out, the South Asian region suffers from the curse of too little or too much water. For four months during the monsoon season, there is too much water. For the rest of the eight months, there is too little. That is why Cherrapunji in Meghalya, which gets about 9,000 mm of precipitation a year is described as the "wettest desert in the world". During the non-monsoon months, there is actually a water shortage in this eastern Indian town. "The region is water rich but yet water stressed," writes Subba.

The Himalaya provide a valuable source of water for drinking, irrigation, energy, industry and transportation. But when they burst their banks Himalayan rivers can make millions destitute. One fifth of Bangladesh is submerged every year, and during bad years like 1986 nearly 70 percent of the country goes underwater. The same floods that destroy also bring valuable silt, replenishing nutrients in the soil. Water makes life possible, but it also takes away lives.

In the mountains, rains bring the annual curse of landslides and erosion which add sediments to already choked rivers. Roads, bridges, and railway tracks are washed away. Numerous glacial lakes located at the head of these rivers can bring destructive flashfloods when they burst. Global warming is gorging many Himalayan glacial lakes with snow-melt which could push through their loose moraine dams at any time with cataclysmic floods downstream.

Managing these rivers and water sources holds promise for the future, but only if they are properly managed for the common good. Appropriate projects, carefully chosen and affordably built, cooperation between countries in the region alone can sustain the healthy agriculture and robust industry to ensure better quality of life for one of the poorest and most-densely populated regions of the world.

South Asia's river systems are the cradle of the civilisations that evolved here over millennia. Today, rivers have come under the jurisdiction of different governments, some of them on not very good terms with each other. Still, the rivers make a mockery of artificial lines on the map. Ideally, transnational water resources planning must respect a river's will and let it flow according to the parameters of a watershed and not national boundaries. Our inability to do this has resulted in half the population of the Indus-Ganga-Brahmaputra belt living below the poverty line even as precious fresh water flows wasted to the sea. Worse, sharing the water of common rivers has now become an issue for conflict between and within nations.

In Himalayan Waters, Bhim Subba brings the total picture of this complex subject to the English-reading public in the region. The easy-to-read and precisely written text is refreshing, the illustrations by Subhas Rai are clear and colourful, and the photographs are well-chosen and illustrative. It is hard to pull off something like this: a text book that looks like a coffee table book, but Subba has done it.

Dipak Gyawali's Water in Nepal, on the other hand, is a seminal and exhaustive collection of past articles that gives in historical perspective the reasons why falling water has not translated into hydro-dollars for Nepal. Gyawali demystifies and de-mythifies water in Nepal. How governments, bureaucrats and politicians over the years made wild promises about how exporting water to India is the panacea that will lift Nepal out of poverty. Water in Nepal lays out the prerequisite questions that need to be asked before that can happen: Who benefits and who holds the key to this vast treasure? Who pays the cost and who reaps the harvest? Gyawali urges a paradigm shift in the way Nepal looks at water, and in doing so turns many long-cherished dreams on their heads. For example, although electricity is a finished product for us, it is only a raw material for the buyer (India), and no country can get rich by exporting just raw materials.

Water Nepal and Himalayan Waters both dissect the Kosi project in India's Bihar district, and how instead of controlling floods the embankments have pauperised the already-poor state, sustained corruption and made that part of India what it is now. Why is this relevant to Nepal? Because every time the embankments are unable to stop floods, the Bihar government and New Delhi bring up the subject of the Kosi High Dam in Nepal. Gyawali gives another example of what he means by paradigm shift: after spending billions and several decades on canal construction for irrigation Nepal and India have both found that private tube-wells sprang up adjacent to the canals and helped boost agricultural production. Farmers, it seems needed water, but kickback-driven politicians and bureaucrats pushed lucrative construction work.

Water is a subject that touches everyone, but it is little understood. Everyone has an opinion on water, and when water is concerned it seems emotion and passion sideline rational and scientific thinking. The simplistic answers and solutions have powerful logic: Nepal can only develop by building large dams and exporting electricity to India, the best way to control floods is to build embankments, widespread irrigation will boost food-production, building storage reservoirs in Nepal is the answer to Bangladesh's flood woes, deforestation in the Himalaya is the reason floods are getting worse in the plains. Both Subba and Gyawali in their books tell us, alas, that the truth is much more complicated than that. What makes it murkier is that politics, populism and geopolitics get mixed up with the science.

This is a pity, because Himalayan rivers play a vital role in the people's battle against hunger, providing water to hundreds of millions of farmers in Bangladesh, Bhutan, Nepal, India and Pakistan. But these countries have yet to develop ways to use this gift for the general good of their people. Mixing water with politics is a disservice to the people who this precious fluid is supposed to benefit.

On the one hand water is getting scarcer, but on the other more and more valuable farmland in the plains is turning flood-prone, or water-logged. Today, there is a better understanding of the behaviour and nature of Himalayan rivers than in the past. New perceptions about floods and water scarcity are emerging. Farmers who were blamed in the past for clearing forests in the hills and making floods worse in the plains have been exonerated. The limited role that forests and watershed management play in regulating floods is better understood.

Embankments, which were initially designed to reduce floods made things worse. India has constructed more than 15,000 km of expensive levees after independence, with Bihar alone having more than 3,400 km. But floods are worse than ever before. Even so, governments in the region still spend millions on conventional and discredited methods of flood and erosion control.

As with the embankments, proponents of the big dams still view them as long-term solutions to meet power, irrigation and flood control requirements of the future. However, big dams are being increasingly challenged by both ecologists and economists who see them as unsustainable due to high environmental, economic, and social costs. Subba avoids polemics and lays out the pros and cons for both schools of thought. But what is clear is that given the political sensitivity of crossborder river sharing, the exorbitant economic cost of large dams, and the growing reluctance of international credit institutions to support these grandiose schemes, their days are numbered.

In his book, Gyawali lays out the famous example of Arun III in Nepal: chronicling the World Bank's hard-nosed policy to force Nepal to agree to an expensive mistake, the politics within Nepal that drove the project, the international alliance of anti-Arun activists that brought it down in 1993. Ten years later, the vindication: because Arun was scrapped, Nepal finds itself in the relatively comfortable hydro-power situation it is in at present. Despite all the mistakes and the politicisation, something in Nepal worked. But neither Subba and Gyawali are knee-jerk anti-dam wallahs, just anti-bad dams.