The research, led by Thiago Couto of the University of Washington, examined the scale and expansion of small hydropower dams worldwide. In total, 82,891 smaller dams were recorded in operation or under construction in 150 countries – that’s 11 small dams for each large dam globally. This number could triple, according to the new study, if all potential capacity is developed, with a further 10,569 small dams already in the planning stages. China leads the way, with over 47,000 small dams currently in operation. the environmental policies and the existing body of scientific knowledge are insufficient to guide and inform the fast expansion of the small hydropower sector.
— source news.mongabay.com