Guy R. Lanza

Dam the rivers and face the consequences

China leads the world in urbanization with more than 665 million people driving an economic growth rate in excess of 9 percent. The rapid growth of China's interior and its policy to renew/upgrade energy production infrastructure provide ample opportunity for poverty reduction while still making substantial contribution to the fight against climate change.

To be successful, China must develop a mix of renewable energy options that are truly green and sustainable. Large hydropower projects do not provide sustainable energy infrastructure for China or any other nation.

Some groups in China claim that hydropower will provide clean energy and alleviate climate change, for it reduces the use of fossil fuel. But pitting rivers against fossil fuels is a lose-lose proposition. The truth is that dams change the natural hydraulic function of rivers by destroying their natural flow dynamics, and the result is a cascade of negative environmental impacts.

The sudden seizure and storage of massive volumes of flowing water and sediment hasten the degradation of water quality, and reduce fish stock and invaluable biodiversity at a time when global water and food supplies are already under immense pressure. Besides, the sediment in dam reservoirs releases greenhouse gases, adding to the problem by contributing to climate change.

Contrary to common belief, controlling rivers' flow dynamics with dams does not provide a long-term solution to floods or droughts. Dams contribute to changes in regional hydrological cycles that combine with the more extreme patterns of weather associated with climate change and result in irregular episodes of flooding, drought and mud-slides.

Advocates of large hydroelectric projects, however, continue to perpetuate the myth of producing cheap, clean, renewable energy with little or no environmental and social costs. Experience shows that the opposite is true. Dam projects across the world have led to the loss of livelihoods of indigenous people and destruction of fisheries - an essential part of their culture and diets - and increased waterborne diseases. Schistosomiasis, already prevalent in the Yangtze River watershed, can increase following the impoundment of the river.

Hydropower projects in China are both numerous and massive in scale. And since the Three Gorges Dam on the Yangtze impounds the longest river in Asia, it is important for China to develop non-hydro options for energy.

China is poised to take the lead and set an example in intelligent planning to provide sustainable and renewable energy options to support its rapid economic and social development. But the plan must be comprehensive and should follow good models like the strategic environmental assessment - a process of appraisal that gives due consideration to environmental protection and sustainable development both. It integrates water resources management, too, which is an approach that combines and harmonizes key economic, social and environmental factors in a planning and management framework. The two approaches can be calibrated to provide sustainable options suitable for China.

To safeguard its rivers and their invaluable ecosystems, China should ensure that dam projects are selected using a basin-wide assessment of the river ecosystem with provisions to avoid harming threatened and endangered species. Before taking a decision to build a new dam, China should address outstanding social and environmental issues from existing dams, and maximize the benefits from existing projects.

Dam projects must provide for the release of environmental flows to help maintain healthy and productive downstream ecosystems. They should consider European Union and other effective global environmental impact assessment standards, and follow guidelines suggested by established expert groups. These groups strongly recommend that the cumulative environmental impact of hydroelectric projects at any scale must be given high priority in the planning process.

China should also take full advantage of the fact that global technology is close to the tipping point where solar energy will be competitive to fossil fuels and hydropower. A 2008 report of a United States-based academy of engineering panel predicts that we can reach solar grid parity in five years. Moving away from hydropower and toward renewable energy from a mix of decentralized options including solar, wind and geothermal is China's best option for long-term sustainable development.

Hydropower is only one source of energy for China and the rest of the world. The cheapest, cleanest and fastest solution is to make the use of energy more efficient. According to the McKinsey Global Institute, developing countries will account for about 80 percent of global energy growth up to 2020, and could cut their demand by more than half if they use existing technologies to improve energy efficiency. "This would leave energy consumption some 22 percent lower than it would otherwise have been - an abatement equivalent to the entire energy consumption of China today."

The author is a professor of aquatic ecology and microbiology at the University of Massachusetts.

(China Daily 06/07/2011 page9)