When the World Commission on Dams reviewed the development effectiveness of dams, multipurpose projects with large dams, power plants and irrigation schemes had the worst social, environmental and economic track record. As the world is grappling for appropriate answers to climate change, influential actors such as the World Bank want to give these complex schemes a second chance. They are wrong. While we need to integrate the concerns of climate change, water, energy and food security, we don’t need to go back to old-fashioned multipurpose schemes like the Narmada dams. And while we need to store water to adapt to a changing climate, we can do so in other ways than the big, centralized reservoirs of the past.
Large dams and reservoirs are not well-suited to a changing climate for two reasons. First, the arteries of our planet are already suffering from a higher rate of species extinction than any other major ecosystem. Climate change will compound the pressure on vital freshwater resources, and will make projects with large ecological footprints unaffordable. Secondly, big reservoirs cannot respond flexibly to the rapid shifts in streamflows that climate change brings about. Dams that reflect past hydrological patterns may become unsafe as storms intensify, and uneconomic as droughts become more frequent.
Climate change has already begun affecting the world’s rivers and dams. Only last month, Bhutan’s Prime Minister Jigmi Thinley warned: “The climate is changing, global warming is real and the impact on our hydrology is very severe… Hydropower may not be the sort of exponential source that we considered it to be.” Countries like Tanzania are suffering frequent brownouts because they depend on hydropower projects that are ill-matched with today’s climate. A new paper in the scientific journal, PLoS Biology, found that “particularly for large [water] infrastructure projects, the risks for investors, communities, and ecosystems are extremely high given uncertainties in future hydrological conditions”. It concluded that “climate-infrastructure mismatches may make poor nations even poorer”.
Future development strategies need to move away from technologies that depend on stable climatic conditions. A recent World Bank report warns that “long-lifespan infrastructure, such as hydropower plants, is generally less adaptable” to climate change. “An adaptation response”, the report finds, “may require a policy decision to diversify away from hydropower”. The International Monetary Fund has encouraged East African countries to minimize their “very significant dependence on hydropower”. And the authors of the new scientific paper recommend making infrastructure less vulnerable by designing for “multiple potential climate regimes”, and building in stages to take changing climate conditions into account.
Luckily, solutions that integrate water, food and energy security with climate resilience exist. They include a wide spectrum of small, decentralized, bottom-up approaches such as local check dams, other water harvesting techniques, mechanic treadle pumps, drip irrigation, and the system of rice intensification. Combining traditional knowledge and innovative techniques, these approaches rely on the initiatives of small farmers, use water efficiently, cost less than large dams, enhance the food security of the poor, and typically have minimal environmental impacts. Similarly, a diverse mix of decentralized renewable energy projects – including wind, small hydro, solar and geothermal – will not only strengthen resilience to climate change. It will also be effective at improving energy access for the rural poor and limiting environmental impacts.
Bottom-up solutions have an impressive track record. The system of rice intensification for example increases yields and makes them more resilient to climate change through reduced use of water, fertilizer and pesticides, but increased attention to soil biology. Its methods have been validated in 42 countries. The small check-dams that Rajendra Singh and his Tarun Bharat Sangh have pioneered have revived several rivers and brought prosperity to arid regions throughout Western India. The simple treadle pumps that Paul Polak and International Development Enterprises have developed have lifted millions of farmers out of poverty. Yet these approaches have so far only received a minuscule proportion of the aid, investment and political support that big dams receive.
While there is no single silver bullet, proper legal, scientific and financial support could scale up effective bottom-up approaches in the water and energy sectors immensely. Local communities and small farmers deserve legal rights to the land and water that they have worked with for generations. Small farms and rainfed agriculture deserve research support on the same scale that was poured into the green revolution. Decentralized renewable energy options deserve priority over big dams if development aid aims to reduce energy poverty in a sustainable manner.
Some 500 representatives of governments, business, academia, aid institutions and NGOs will meet in Bonn in November to discuss ways to strengthen water, energy and food security under climate change. They should give the pioneers of bottom-up solutions the credit that they deserve, and call for a massive shift of incentives, aid and investment flows from the centralized ways of the past to the resilient approaches of the future.