With half the planet’s large dams within its borders, China is the epicenter of global dam building. A new report warns that reckless dam construction has brought the country’s river ecosystems to the point of collapse.

Since the 1950s, China has dammed, straightened, diverted and polluted its rivers in a quest for rapid industrialization. Many of the projects built under Mao Zedong and his successors had disastrous environmental, social and economic impacts.

In the new millennium, the Chinese government realized that its ruthless dam building program threatened to undermine the country’s longterm prosperity and stability. In 2004, Prime Minister Wen Jiabao suspended dam construction on the Nu (Salween) and the Jinsha (upper Yangtze) rivers, including a project on the magnificent Tiger Leaping Gorge. The government created fisheries reserves and strengthened environmental guidelines.

The growing climate crisis ended the period of relative caution in building dams. In 2009, the Chinese government committed to reduce the carbon intensity of its economy by 40-45% by 2020. As a consequence, the government launched a relentless new dam building effort under its 12th Five-Year Plan (2011-15).

The current plan commits to approving 160 gigawatts of new hydropower capacity by 2015 – more than any other country has built in its entire history. It prioritizes 50 large hydropower plants on rivers including the Jinsha (upper Yangtze), Lancang (upper Mekong), Yarlung Tsangpo (Brahmaputra), and upper Yellow. The plan also authorizes the construction of five of the 13 dams on the Nu River that the government had stopped in 2004.

Alarmed by the pace of re­newed dam building, experts from Chinese environmental organizations have recent­ly published what they call the “last report” on China’s rivers. The report highlights four main problems with the current wave of hydropower development:

• Dams are seriously degrading China’s freshwater ecosystems. They are drying up rivers and lakes, inundating fertile floodplains, and compromising the capacity of rivers to clean themselves. As a result, the Three Gorges and other reservoirs have been turned into waste dumps. The Chinese river dolphin, which plied the waters of the Yangtze for 20 million years, is now extinct, and other freshwater species are under threat. Fish sanctuaries created to mitigate the impacts of dam building exist on paper only, or have been curtailed to allow space for more dams.

• Dams further impoverish poor communities. According to former Prime Minister Wen Jiabao, dam building has displaced 23 million people in China. Displaced populations are frequently cheated and bullied by corrupt local officials, and the promised jobs or replacement lands often don’t materialize. As dam building moves upstream into mountain areas, ethnic minorities are particularly affected by displacement.

• Reservoirs are destabilizing geologically fragile river valleys, creating frequent landslides, and compounding earthquake risks. Scientists suggest that the Zipingpu Dam in Sichuan may have triggered the Wenchuan earthquake, which killed at least 69,000 people in May 2008. Dam cascades in the seismically active valleys of southwest China are a particular concern for triggering earthquakes and being impacted by them.

• The decision-making process is in disarray, and government regulations are no match for the new dam-building rush. Integrated river basin plans and environmental impact assessments are almost always carried out after dam construction starts. Large projects such as the Xiluodu and Xiangjiaba dams even began construction before they received their final approval.

Even while energy intensive industries continue to suffer from over-capacity, China uses energy less efficiently than other countries at a comparable level of development. A less energy-intensive development path will be required to reduce the pressure on China’s ecosystems. In the meantime, the new report proposes a system of “ecological redlines,” similar to the protected Wild and Scenic Rivers in the US, which could save critical ecosystems from being dammed.

Since the report was published, activists have found new hope. In April, China’s National People’s Congress adopted a new Environmental Protection Law that for the first time foresees stiff penalties for violators and allows environmental organizations to file public-interest lawsuits. Around the same time, the new Prime Minister Li Keqiang expressed repeated concerns about the health of Chinese rivers.