More than 1,000 opponents of plans to build a dam on China’s biggest freshwater lake have signed a petition calling for the project to be abandoned, saying it will take a huge toll on endangered migratory birds and the rare Yangtze finless porpoise. In an open letter to authorities in Jiangxi province last week, Let Birds Fly, a Hangzhou-based environmental group, said it would be “extremely irresponsible” of the government to approve the project for Poyang Lake. “It goes against China’s efforts of to conserve the environment … It would do irreversible [damage] to our ecosystem,” the signatories said in the letter. Two endangered Chinese finless porpoises found dead in Yangtze River as species struggles for survival The letter came after the government released the plans online for public feedback. The 13 billion yuan (US$2 billion) project includes building a 3km-long (1.86 miles) and 23.4 metre-tall sluice gate between Poyang and the Yangtze River, to stop water flowing out of the lake during the annual dry season between November and March, according to the notice posted online. It would also aid irrigation, urban and rural water supply and shipping on the lake, the notice said. Poyang’s water levels fluctuate widely between the wet and dry seasons but the dry spells have grown longer in recent years , turning parts of the lake into wetlands in the winter. Addressing a seminar on the project on the weekend, Liu Shukun, a senior engineer of the China Institute of Water Resources and Hydropower Research, said one big reason the lake was drying up was the Three Gorges Dam upstream, which limited the flow of water downstream. Other factors included the construction of reservoirs nearby and climate change. The project has been on the government’s drawing board for more than a decade but was shelved mainly because of objections from environmentalists. In 2009, the Jiangxi government sent the plan to the State Council for approval but it was knocked back over environmental impact concerns. Seven years later, the Jiangxi water resources department tried to get the project off the ground again, releasing an environmental impact assessment. But this, too, raised objections from environmentalists, scientists, and the public. WWF, which has been vocal about protecting the endangered Yangtze finless porpoise in the lake, called for the project to be abandoned altogether and new solutions found. Conservationists said building dams would have an irreversible or uncertain impact on water quality, fish diversity and the porpoise’s habitat. They said that increasing the water flow in winter would also submerge the lake’s wetlands, which are a source of food for migratory birds. If China’s finless porpoise is doomed, so is the mighty Yangtze River on which it depends Jiang Yi, head of Yangtze finless porpoise conservation at the China Biology Diversity Protect and Green Development Foundation, a Beijing-based environmental NGO, said the lake was the most important habitat for the species. “China only has 1,012 Yangtze finless porpoises and 457 of them are in Poyang Lake,” Jiang said. Yue Hua, another conservationist at the foundation, said 98 per cent of the estimated 4,000 Siberian cranes left in the wild spent winter at the lake. According to Jiangxi government data, 65 species of water birds with a combined population of 667,000, were spotted at the lake in 2019. Wang Hao, from the Chinese Academy of Engineering, agreed that the Three Gorges Dam and other upstream reservoirs were the main reasons for the fall in the lake’s water levels, but he said the new project would be a solution. “As long as these reservoirs are in place, the water levels of the lake will continue to fall every year between September and Octoberand this will inevitably become a natural and irreversible trend,” Wang said. Building a dam between the lake and the Yangtze could help boost fish stocks and the porpoise population, he said. “[We should see] this as an environmental project,” Wang said.