China's state-owned dam builders are failing to keep their promises to protect the planet when developing hydropower projects abroad - increasing the threat of environmental and social problems, according to a new study by green group International Rivers. Some experts believe such business practices - if not improved - could harm Chinese companies' hopes of securing contracts for infrastructure projects as part of Beijing's ambitious "One Belt, One Road" initiative. This development strategy includes the Silk Road Economic Belt, linking the nation with Central Asia, Russia and the Baltic states over land, and the building of maritime routes with nations in Southeast Asia and around the Indian Ocean. The study looked at seven Chinese power companies involved in overseas dam projects: Sinohydro, Gezhouba Group, Three Gorges Corp, China Huadian Corp, China Huaneng Group, PowerChina Resources, and China Datang Overseas Investment. Five of the seven received lower scores for project performance than for policy commitment in the overseas dam projects, according to a benchmark developed by the California-based International Rivers, which compares their standard of their work offshore with international best practices. "The three companies [PowerChina Resources, Huaneng and Datang] who ranked last in project performance have significant gaps between project performance and policy commitments," said Stephanie Jensen-Cormier, the green group's China programme director. International Rivers carried out on-site research and conducted interviews with workers and local communities as part of a review of environmental and safety management procedures on one project run by each company in Cambodia, Malaysia, Laos and Ecuador. Sinohydro, which is working on the Coca Codo Sinclair hydropower plant, in Ecuador's Amazon basin, was ranked top for both its policy commitments and actual performance. Huaneng was ranked last for its policy commitment, and Datang last for its work on the ground. The study gave the seven companies high marks for their plans involving environmental management and the review of their project's environmental impact; the marks were roughly on a par with international standards. However, they performed particularly poorly when carrying out their environmental impact assessments (EIA). In Cambodia, for example, companies started construction work even before the assessments had been approved. Some companies failed to respond to the comments of local stakeholders in the reports, and none of the project's assessments was publicly disclosed, the environmental group's study found. A spokesman for PowerChina Resources argued that the company's poor rating was because of a "gulf in understanding" between Chinese companies and international non-governmental organisations. "Some of the information they required was a business secret, which cannot be shared," he said. Also, a request for the company to visit local communities "household by household" was not in line with domestic practice, he added. Wang Yongchen, an environmental activist who has campaigned against the widespread damming of China's major rivers, said the construction companies were notorious for the strength of their political manoeuvring and their poor standards of public consultation. Practices such as companies withholding project information from the public were "common" among businesses involved in domestic projects, Wang said. Mainland environmentalists have often criticised China's powerful state-owned companies and local government authorities for refusing to heed public concerns over dam projects; they have pressed ahead with dams that have disrupted the natural ecology of areas and displaced local communities. "Now I'm worried that they're taking such practices to foreign countries and damming the world's rivers, especially in underdeveloped regions, where rivers were once free-flowing," Wang said. Yet such business practices could lead to challenges for these Chinese companies in "more democratic" countries because they would face opposition such as public protests, which could derail the construction projects, Wang added. In one such case, construction of the China-led Myitsone dam project in Myanmar was suspended by the military-backed, civilian-led government after protests by locals. In a separate case, thousands of Nicaraguans demonstrated last month against the planned construction of a canal linking the Atlantic and Pacific oceans. The US$50 billion project is being built by Chinese businessman Wang Jing, whose company has tabled an environmental impact assessment to the Nicaraguan government for approval. "The Chinese companies have been facing big challenges in the overseas market," Jensen-Cormier said. "We learned that they are struggling and were interested in knowing why." Jensen-Cormier said that pressure from NGOs could help Chinese construction companies to better understand that their environmental and social track records were "critical components" when they tried to compete for overseas projects in future. Knowing that they were being monitored and assessed could also help them improve, Jensen-Cormier added. Some Chinese companies are already learning to live with such pressures and have benefitted because of their improved reputations. A spokesman for Sinohydro, which now runs more than 500 projects in 80 countries, said it had been working with organisations including The Nature Conservancy, International Hydropower Association and International Rivers since 2009, and was becoming more aware that benefits to local communities were an important part of the success of overseas projects. "Chinese companies started setting foot in overseas projects no more than 20 years ago and there is still a lot to learn about becoming more localised and internationalised," the spokesman said. However, it may take some time for all of China's construction companies working abroad to catch up with international standards. In January 2014, China started to require that companies publicly disclose full environmental impact reports. This overhaul of the domestic policy would help Chinese companies to get used to a higher level of transparency and eventually benefit the overseas projects they were involved in, Jensen-Cormier said. "However, the current laws and regulations in the host countries of the projects still have a significant impact on the Chinese companies' performance," she said. "Changes of this kind will take long time." Datang, Three Gorges Corp and Gezhouba Group could not be reached by the South China Morning Post for comment, while Huadian and Huaneng did not respond to requests at the time of publication.